3^rd International Conference and Exhibition on Lasers, Optics & Photonics September 01-03, 2015 Valencia, Spain

Biography:

Tony Krier is professor of physics at Lancaster University where he is director of the Quantum Technology Centre. He obtained his PhD in 1983 and joined Lancaster in 1989, where he founded the mid-infrared optoelectronics research group. He was promoted to Reader in 1999, then to Professor in 2003 and has published more than 190 papers. He has worked extensively on mid-infrared (2-5 μm) materials and devices and in 1996 he founded the international mid-infrared materials & devices conference (MIOMD). His recent work concerns antimonide nanostructures and dilute nitride alloys for use in mid-infrared lasers, photodetectors and solar cells.

Abstract:

The mid-infrared spectral range is technologically important for a variety of applications including gas sensing, optical spectroscopy, bio-medical diagnostics etc. Although type II InSb/InAs QDs have shown electroluminescence up to room temperature and are a promising candidate for diode lasers at wavelengths longer than 3 µm , there have been only a few reports of InSb QD lasers. In this work, we demonstrate coherent emission from InSb QDs at wavelengths between 3.02 µm and 3.11 µm at temperature, Tmax up to 120 K using pulsed excitation, with a threshold current density, Jth~1.6 kA cm-2 at 4 K. The gain and spectral tuning behaviour were also investigated.
We developed a hybrid laser structure containing ten sheets of sub-monolayer InSb QDs in an InAs waveguide sandwiched between a p-InAs0.61Sb0.13P0.26 lower cladding layer grown by liquid phase epitaxy and an n+ -InAs plasmonic upper cladding layer grown by MBE. Fig. 1 shows the laser peak blue shifts with increasing temperature when T<50 K. For T>50 K, the peak moves to longer wavelength as temperature increases. The modal gain of the laser was extracted from lasers with different cavity lengths resulting in a value of 29 cm-1, (or 2.9 cm-1 per InSb QD layer), which is close to that found in type II QW lasers emitting at similar wavelengths. The material gain was estimated to be 19 x104 cm-1, which is similar to that for type I QDs.

Biography:

Gaetano Scamarcio is full professor of Physics since 2002. He graduated in Physics in 1985 and received the PhD in Physics in 1989. From 1989 to 1990 he has been a research fellow at the Max-Planck-Institute für Festkörper-forschung, Stuttgart, Germany, and in 1992 a visiting scientist at the Walter-Schottky-Institute, Garching, Germany. In the period 1994-1996, in 2000 and 2001 he has been a visiting scientist of Bell Laboratories, Lucent Technologies (formerly AT&T), Murray Hill, NJ (U. S. A.). In 2006 he has been invited professor at the University of Paris 7.
His main research interests are in the fields of quantum cascade lasers, optical, vibrational and transport properties of semiconductor structures at the nanoscale, spectroscopic techniques for real-time monitoring of optoelectronic devices, optoelectronic sensors for mechatronics. His research activity is documented by 220 ISI publications, and 7 filed patents. His publications gathered more than 2200 citations with an ISI h-index of 26. He has given 50 invited presentations at international conferences and workshops. Awarded researches programs comprises contracts funded by European, UE, ESA, Italian, MIUR, MAP, CNR, INFM as well as regional agencies and industrial projects for an overal budget > 50 M euro.

Abstract:

After reviewing the features of self-mixing interferometry in quantum cascade lasers, its inherent ultra-stabilkity and its several metrological applications, I will present our recent results on a novel contact-free method based on the use of THz quantum cascade lasers operating under optical feedback to image in reflection mode the free electron plasma photogenerated onto a semiconductor surface. Self-mixing interferometry is also used to demonstrate the possibility to produce sub-wavelength patterns acting as metamaterials in semiconductors pumped by a spatially modulated near-infrared beam.

Biography:

Philippe Christol is a professor in Electronic & Electrical Engineering and member of the Electronic Institute (IES) of Montpellier University, France, since 2005. He is specialist of infrared photodetection, in particular of antimonide-based photodetectors grown by Molecular Beam Epitaxy (MBE) on GaSb substrate. He is now Deputy Director of the IES laboratory (~180 members). He is author/co-author of over 80 publications in refereed journals, a book chapter and contributed to over one hundred communications in international conferences. His research interests currently focus on electrical and optical properties of new InAs/InAsSb and InAs/GaSb superlattice infrared photodiodes.

Abstract:

The last past years, Type-II super lattice (T2SL) made of InAs/GaSb nanostructures has emerged as a new material technology suitable for high performance infrared detectors. This was possible because T2SL is a particular quantum system with non-standard optical and electrical properties. Among T2SL specific properties, one of the main interesting is that several structures, with different InAs to GaSb thickness ratios in each SL period, can target the same cut-off wavelength. Recent previous work reports the study of photodiodes with different SL periods having the same cut-off wavelength at 5 µm at 77 K. This study shows the strong influence of the SL composition on dark current measurements, shape of spectral responses, quantum efficiency and type of background doping concentration of nid InAs/GaSb SL active zone. The objective of this communication is to use the flexibility of T2SL to fabricate by MBE a pin photodiode where the active zone is made of different SL periods. Influence of the SL period composition on the electrical and electro optical characterizations are reported and discussed. The results show that optimized SL structure for the MWIR domain can be designed by combining the best of each SL periods.

Biography:

J Wagner received the PhD degree in Physics from the University in Stuttgart, Germany, in 1982. From 1982 to 1984 he worked at the Max Planck Institute for Solid State Research, Stuttgart, Germany, in the group of Prof. M Cardona before joining the Fraunhofer-Institute for Applied Solid State Physics, Freiburg, Germany, in 1985. There he is currently Deputy Director and Head of the Optoelectronics Department. He is also Professor at the Institute of Physics of the University of Freiburg and an associated member of the Materials Research Center Freiburg (FMF). His current research interests include III/V-semiconductor based optoelectronic devices in particular for the infrared spectral range, as well as their integration into modules and systems. He is author or coauthor of 460 scientific publications including several review papers and book chapters.

Abstract:

Widely tunable quantum cascade lasers (QCL) are ideal light sources for spectroscopic sensing exploiting characteristic finger print absorption of molecules in the mid-infrared (MIR) spectral range. Such broadband tunability can be achieved by placing a QCL chip with a broad gain spectrum into an external cavity (EC-QCL), using e.g. a diffractive grating as wavelength-dependent feedback-element. This way wavelength tuning over >25% of the central wavelength can be achieved routinely in the MIR spectral range. EC-QCLs deliver a well collimated low-divergence output beam with high spectral brightness, which enables a range of new applications. These include in-line MIR spectroscopic sensing of substances in aqueous solutions and MIR backscattering spectroscopy for stand-off detection of hazardous substances. First we report on recent advances in broadband-tunable MIR EC-QCL technology by presenting a first implementation of a rapid scan EC-QCL, employing a custom-made large diameter (=5 mm) MOEMS scanning grating in Littrow-configuration as wavelength-selective optical feedback-element. This way, a scanning rate of 1 kHz was achieved, which corresponds to 2000 full wavelength scans per second. Second, exemplary case studies of EC-QCL based MIR spectroscopy will be presented. These include in-line spectroscopy for the detection of contaminants in water as well as imaging MIR backscattering spectroscopy for the detection of residues of explosives and related precursors on various kinds of surfaces in a realistic environment.

Biography:

Besnard Pascal has completed his PhD degree in Physics from University of Rennes and Postdoctoral studies at Ontario Lightwave and Laser Research Center, Toronto, ON, Canada. He is Professor at ENSSAT and was the Head of the Optronics department during 6 years and at the Head of the Laser Physics Group from 2000 to 2012. Since 2012 he is the Director of the unity CNRS Foton (optical Functions for the sciences of communication). His principal research interests include laser physics, noise, optical injection, optical feedback, and mode-locked lasers using semiconductor and fiber technology for optical communications and sensors.

Abstract:

Several scientific domains including defense, metrology, aerospace, and telecommunications require low frequency and intensity noise sources. Coherent lasers could improve detection and could offer new perspectives in the fields of instrumentation for high-speed optical telecommunications, microwave-photonics systems and highly sensitive sensors. If very coherent lasers have been realized in metrology or following fundamental studies (for examples, Menlo systems), their cost or complexity is prohibitive and there is a need for compact, low-cost coherent lasers (~Hz linewidth). We propose to use multi-stokes Brilouin lasers to reach such a goal (Hey Tow et al., “Towards more coherent laser sources by using a simple and compact Brillouin laser made of micro structured chalcogenide fiber” IEEE Photonics Technology Letters 25, 3, 2013). Generation of multiple Stokes orders with a single pump enables to filter out the pump noise as many times as the number of nonlinear components, which leads to a drastic reduction in the frequency noise, accompanied by a reduction in the intensity noise. We give for the first time frequency and intensity noise measurement for high-order Stokes components for Brillouin fiber lasers. We discuss future improvements and the impact of such low-cost, compact lasers.

Biography:

Shien-Kuei Liaw received the Ph.D. degree from National Chiao-Tung University, Taiwan, in 1999. In 1993, he joined the Telecommunication Laboratories, Ministry of Transportation and Communications, Taiwan. In 1996, he was a visiting researcher at Bellcore (now Telcordia), Red Bank, NJ. USA in 1996 and a visiting Professor at University of Oxford, UK in Autumn 2011. He is now a distinguished Professor and the Director of Optoelectronics Research Center of National Taiwan University of Science and Technology, Taiwan. He has authored and co-authored over 200 international journal articles and conference presentations. His research interests include optical communication, fiber devices and fiber sensing.

Abstract:

Recently, much more attention has been directed to diode-pumped single-longitudinal-mode (SLM) fiber lasers because of their high reliability, compactness, and capability of shot-noise-limited operation in the megahertz frequency range. In this paper, a SLM linear-cavity fiber laser at C-band wavelength is proposed and demonstrated by using only two subring cavities, either in serial or parallel connection. The employed saturable absorber filter and two subring cavities successfully suppress the multi-longitudinal-mode oscillation caused by spatial hole burning in a linear cavity. Tunable laser sources have seen various applications in recent years such as optical switching, network protection or digital communication. Among various tunable lasers, fiber lasers now compete directly in several domains with semiconductor lasers because they present the advantages of high brightness, low intensity noise, thermal stability, excellent coupling into a single mode fiber and better compatibility with fiber components. In this paper we develop an L band tunable erbium-doped fiber laser (TEDFL) using a broadband fiber mirror (BFM) and a tunable fiber Bragg grating (TFBG) as cavity ends. Several characteristics such as the gain fiber length, threshold pumping power, pumping efficiency and side-mode suppression ratio (SMSR) are studied. The wavelength tuning function is also demonstrated.

Biography:

Anna Szerling received the MSc in Physics from the Warsaw University of Technology, Warsaw, Poland, in 2002 and PhD degree in field of electronics from the Institute of Electron Technology, Warsaw, Poland, in 2008. Her main research interests include processing and characterization of the semiconductor devices. She currently works on the THz and MIR quantum cascade lasers. For 10.2014 – 11.2014, she joined the group of Prof. M. Razeghi at CQD, USA, as a Visiting Scholar.

Abstract:

The Quantum Cascade Laser are valuable as the sources for the detection of large organic hydrocarbon molecules like the BTX compounds in the 12–16 µm region or for radio-astronomy as local oscillators in heterodyne detectors. In this work, long wavelength 16 µm quantum cascade lasers will be demonstrated at room temperature with high peak output power using a bound-to-continuum structure design. The structure was grown by gas sources molecular beam epitaxy and consist of a 45 period active region embedded in an optical waveguide. The devices were processed in 50 - to 70 - µm wide mesa using wet chemical etching and a SiO2 for passivation. Multimode emission with pulsed peak power up to 700 mW at 30°C and above 200 mW at 100°C will be presented. The emission spectrum consists of modes around 641 cm-1 (λ~15.6 µm) and around 602 cm-1 (λ~16.6 µm).

Biography:

Miriam Serena Vitiello received the Master degree in Physics (cum laude) in 2001 and the PhD Degree in Physics in 2006 from University of Bari. Since 2010 she is staff research scientist at the National Research Council in Italy, and she is leading the Terahertz photonics group at the Nanoscience Institute - NEST Laboratory and Scuola Normale Superiore in Pisa. She was visiting scientist for short research stages at the Technical University of Delft (April 2004, December 2004), at the Technische Universität of Munchen (July 2004) at THALES in Paris (2005) and at the University of Paris VII (2006). She coordinates the activities of Terahertz Photonics in the CNR Department of Physical Sciences and Technologies of Matter and she is a member of the scientific committee of more than 40 international conferences in the field of photonic devices. She is co-author of more than 100 refereed papers on international journals, holds 1 patent and delivered more than 60 invited talks at international conferences and more than 30 lectures at International Universities. She was the first European scientist to be awarded with the SPIE Early Career Achievement Award (2015). For her scientific research Miriam Vitiello has been granted the optoelectronics and photonics prize " Sergio Panizza " of the Italian Physical Society (2012), an International Scientific Author Award (USA, 2005) and two National Young Author Award (2004, 2005).

Abstract:

Terahertz (THz) radiation lies in the region of the electromagnetic spectrum, loosely defined as the 30-300 μm wavelength region that is often called “THz gap”. Recent technological innovation in photonics and nanotechnology is now enabling THz frequency research to be applied in an increasingly widespread range of applications, such as information and communications technology, sensing, medical diagnostics, global environmental monitoring, homeland security, and quality and process controls. Most of these applications require systems with targeted sensitivity and specificity exploiting advanced quantum devices, novel materials and technologies. To address the above application requirements, high power, widely tunable sources with controlled and directional beam profiles, together with high-speed and high-sensitivity resonant detectors need to be developed. This requires parallel developments in semiconductor materials and hetero structures, including micro/nano structuring and plasmonics, as well as related multifunctional THz optical components. The talk will provide an overview of our recent technological developments of Terahertz quantum cascade lasers, from the development of quasi-crystal THz intersubb and lasers, 1. To novel DFB concepts exploiting bi-period feedback gratings to control the emission frequency and the output beam direction independently. 2. A final emphasis on our micro cavity approaches for continuous tuning of THz QCL emission and waveguide adapters for efficient THz radiation out-coupling will be provided.

Biography:

Mi-Yun Jeong is an Associate Professor in the Department of Physics at Gyeongsang National University, Jinju, Korea. She received her BS degree from Gyeongsang National University, and her MS (2001) and PhD (2007) degrees from Korea University, under the guidance of Prof. D. G. Lim. Her current research interests include the second-order nonlinear optical effects of octupolar crystals, nanophotonics, plasmonics, and continuous tunable cholesteric liquid-crystal lasers. She has published 39 papers in peer-reviewed journals.

Abstract:

Cholesteric liquid crystals (CLCs) have become promising candidates for photonic crystal laser devices owing to their unique optical characteristics in mirror less lasing, as well as micron-sized thickness, low threshold, and lasing tunability in the full visible spectral range. In this paper, we introduced in-situ study on optical properties and continuous laser wavelength tuning in cholesteric liquid crystal laser array. General and polymerized CLC laser devices were fabricated to have fine-structured pitch gradient in a wedge CLC cell and to have tuning resolution less than 0.3 nm in abroad spectral range. The comprehensive optical properties of the laser lines and fluorescent spectrum generated by a CLC laser array were studied; the laser lines generated from a CLC with a right-(left-) handed circular helix were right-(left-) handed circular polarized, respectively. We found out that inside the photonic band gap, the CLC structure with right-(left-) handed helicity suppressed the fluorescence generated with right (left) circular polarized light, and instead the suppressed right (left) circular polarized light energy moved to the outside of the photonic band gap, so we can say that the fluorescence intensity outside of the photonic band gap is enhanced with right (left) handed circular polarized light. Depending on the position of the photonic band gap, the fluorescence quantum yield value increased by up to ~15%. And the polymerized CLC devices had good stability for a time of more than 1 year, and in response to strong external laser light sources, and thermal perturbation. And dynamic laser tuning by electric field and temperature control were also studied.

Biography:

Stephan Sprengel was born in Erding, Germany, in 1987. He received the Dipl. Phys. degree from the Technische Universität München, Germany in 2012. Since then he has been working towards the Ph.D degree at the Walter Schottky Institut, Technische Universität München. Currently he is engaged in the research on InP and GaSb-based type-I and type-II quantum well lasers, LEDs and Photodiodes for the mid infra-red including design, epitaxial growth, manufacturing, and characterization. He is a member of the Deutsche Physikalische Gesellschaft, and the IEEE Photonics Society.

Abstract:

Lasers operating in the near- and mid-infrared have many applications - Medical sensing, surgeries, biosensing and contactless highly sensitive gas detection. In this range, InP-based edge emitting lasers and VCSELs using type-I Quantum Wells (QW) offer excellent performance up to 2.3 µm wavelength. Beyond this wavelength, edge emitting lasers based on GaSb demonstrate low thresholds up to 3.7 µm. For VCSELs as well as for III-V on silicon concepts, on the other hand, GaSb is not the material of choice, since the process as well as growth technology are not as far developed as for InP. In this talk we present an innovative concept for InP-based edge emitters and VCSELs for 2-3 µm, using type-II QWs. In the center, three type-II quantum wells are implemented. Each consists of a GaAsSb hole-confining QW surrounded by two GaInAsQWs for electron confinement, forming a W shaped band structure. These W-shaped QWs are separated by tensile strained GaAsSb. Additionally, the structure includes electron and hole blocking layers for electrical confinement. For optical confinement, wave guiding and cladding layers are surrounding the structure. We present lasers at 2.5 μm with threshold current densities of only 0.31 kAcm-2 extrapolated to infinite length corresponding, to 0.1kAcm-2 per QW. Furthermore laser at 2.7 µm are presented, operating up to 80°C in pulsed mode. Additionally, a concept for InP-based type-II VCSELs is discussed. First VCSEL results at 2.5 µm wavelength are very promising.

Biography:

Bruce Wessels is the W.P. Murphy Professor of Materials Science and Engineering, and Electrical Engineering and Computer Science at Northwestern University. He received his undergraduate degree from U. of Pennsylvania and PhD degree in Materials Science from MIT. He is a fellow of APS, OSA and ASMI. He is author/co-author of 360 articles on electronic, magnetic and optical properties materials and devices. He is the holder of 15 U.S. patents. He is a former president of TMS.

Abstract:

Due to an exponential increase of information processing and communications traffic requirements, there are needs for active devices for photonic integrated circuits that operate at 50 GHz and above. One way to increase the bandwidth of an EO modulator is to decrease its size. In this paper, we report the simulation, design, fabrication and characteristics of a millimeter scale, EO modulator operating in the V-band at a wavelength of 1550 nm based on BaTiO3 thin film platform. Using two-dimensional photonic crystal (PhC), decreasing its length and optimizing device design based on our recent simulations of EO and microwave characteristics 50 GHz devices were demonstrated. Integration of these active devices on silicon will also be discussed.

Biography:

D Botez is Philip Dunham Reed Professor at the University of Wisconsin-Madison. He received his PhD from University of California, Berkeley. He is co-inventor of the resonant-optical waveguide array concept which represents the first photonic-crystal laser structure for spatial-mode control. His recent work focused on mid-infrared quantum cascade lasers (QCLs), which led to the first model for carrier leakage in QCLs. He is a Fellow member of the IEEE and OSA, and recipient of the 2010 OSA Nick Holonyak Jr. Award. He has authored or co-authored more than 400 technical publicationsof which over 300 were refereed, and holds 52 patents.

Abstract:

Resonant leaky-wave coupling of antiguides has been used for phase-locking near-infrared (IR) lasers to high pulsed (10 W) and CW (1.6 W) near diffraction-limited (D.L.) powers. The structures are analogous to 2nd-order lateral distributed-feedback (DFB) structures; thus, they represent high-index-contrast (HC) (Δn ≈ 0.10) photonic-crystal (PC) structures that allow global coupling between array elements in an in-phase mode of uniform intensity profile. For mid-IR QCLs coherence over large apertures has been reported from PCDFB lasers and master-oscillator power-amplifier (MOPA) structures. PCDFBs involve diffraction gratings; thus, inherentlyhave low index contrast (Δn ~ 0.008) and have shown near-D.L. operation to only 0.5 W/facet pulsed power. Flared MOPAs, have shown near-D.L operation to 3.9 W, but have no index steps; thus, are vulnerable to thermal lensing in quasi-CW or CW operation. We have implemented resonant leaky-wave coupling in 8.4 μm-emitting arrays of QCLs. Preliminary results are 5.5 W near-D.L. peak powers. Such HC-PC structures hold potential for > 5 W quasi-CW coherent power in the 8-10 μm wavelength range, and > 5 W CW coherent power in the 4.5-5.5 μm wavelength range. Furthermore, in combination with single-lobe-emitting, 2nd-order metal/semiconductor gratings, such arrays hold potential for >15 W CW surface-emitted, coherent power from 2-D HC-PC mid-IR QCLs.

Biography:

Weidong Chen is full Professor of Physics at the Université du Littoral Côte d’Opale (ULCO) in France. He received his PhD degree in 1991 from the Université des Sciences et Technologies de Lille (USTL) in France. Prior to joining the ULCO in 1993, he was an Assistant Professor at the USTL where he conducted research focusing on the development of laser sideband-based heterodyne THz spectrometer and its application to molecular rotation spectroscopy. His current research interests include developments and applications of photonic instrumentation (based on QCL, LED or optical parametric source) for optical metrology of atmospheric species: Trace gases (concentration, isotope ratios) and aerosols (optical properties). He has published more than 130 refereed technical papers and has co-authored over 140 presentations in the international conferences.

Abstract:

Chemically reactive atmospheric species play a crucial role in tropospheric processes that dominate regional air quality and global climate change. Contrary to long-lived species (such as greenhouse gases), real time in situ sensing of short-lived atmospheric molecules represents a real challenge due to their very high reactivity resulting in short lifetimes (of around 1-100 seconds) and ultra-low concentrations that measure in parts per billion by volume (PPBV) to parts per quadrillion by volume (ppqv). In this talk, we will overview our recent progress in the development of photonic instruments for in situ monitoring of such atmospheric species (like nitrous acid (HONO), nitrate radical (NO3), nitrogen dioxide (NO2). The experimental arrangements, based on the advanced photonic technologies (such as quantum cascade laser, light emitting diode) combined with selective and sensitive long optical path length enhanced absorption spectroscopy, as well as their applications to field observation and smog chamber study will be presented.

Biography:

Giuseppe Leo (born in 1966) received a Master in EE at “La Sapienza” University of Rome (Italy) and a PhD in Physics at the University of Orsay (France). From 1992 to 2004 he has been with the Rome-III University as assistant professor and then as associate professor. Since 2004 he has been full professor at the Paris Diderot University (France) and Head of the Nonlinear Devices group of MPQ Laboratory since 2006. His research domains include nonlinear optics and quantum optoelectronics, with a focus on AlGaAs platform. He has coordinated several research programs and published 80 articles, 9 book chapters and >150 conference papers. He has also edited 1 book and registered 3 patents. He is the director of the Denis Diderot School of Engineering.

Abstract:

Frequency conversion can be very efficient in whispering gallery mode semiconductor microresonators, thanks to high optical confinement and modal overlap. The crystallographic symmetry of AlGaAs, along with the circular geometry, provides effective quasi-phase matching without the burden of domain inversion. In this framework, some experimental studies have been recently reported on Second Harmonic Generation (SHG) in GaAs WGM microdisks. However, GaAs does not allow working with a Fundamental Frequency (FF) mode in the third fiber window of the telecom range, since the SH photon energy exceeds the energy gap and two-photon absorption losses are high up to 1800 nm.
Here we report on the demonstration of CW SHG in Al0.4Ga0.6As suspended microdisks on GaAs pedestal, with FF wavelength around 1.55 µm and an efficiency  = 0.7ï‚´10-3 W-1 comparable to state-of-the-art monolithic telecom devices. This result was obtained via the evanescent coupling between the disk and a tapered fiber, with 3.5 mW input power injected in the fiber.
Then we discuss the down-conversion that can occur in the same microdisk, with inverted roles for the SH (which becomes the input pump) and FF (which corresponds to the output signal and idler). In this case, with 3 ps pulses and a repetition rate of 300 kHz, a peak power of about 10 kW at 775 nm can provide signal and idler peak power of about 5 µW at degeneracy.
Finally, we illustrate the fabrication of the monolithic counterpart of such submicron-system, with a suspended AlGaAs nanowire in lieu of the fiber.

Biography:

Jwo-Huei Jou received his PhD in 1986 from University of Michigan, Ann Arbor, Michigan, USA, and worked as a Postdoctoral visiting scientist at IBM-Almaden Research Center, CA, USA, till 1988 before becoming a faculty in NTHU. He chaired the department from 2006 to 2009. He has published more than 120 journal papers and filed and/or been issued more than 60 patents, and has been serving as an editor of Fluorescent Materials and else.

Abstract:

Hydrocarbon-burning lighting measures, such as candles, oil lamps or torches, provide pleasantly warm-sensation, but are energy-wasting with problems like burning, carbon-blacking, flickering, oxygen consumption, and carbon-dioxide emission etc. Whilst, electricity-driven light sources, such as fluorescent tubes and LEDs, are energy-saving, but may cause blue hazards, including discoloring the paintings of van Gogh and Cezanne, irreparable damage to the retina of human eyes, and suppression of melatonin secretion etc. Notably, “Electric light at night may explain a portion of the breast cancer”, as reported by Stevens et al. in 2014. Undoubtedly, there is an urgent need for a blue-hazard free lighting source to safeguard human health. However, challenges arise for such a lighting source as high light-quality is desired while meeting the power-saving trend. Could one have an energy-saving, healthy lighting source with high light-quality to initiate lighting renaissance? To demonstrate such a possibility, we employ OLED technique with a high band-number of candlelight emission complementary emitters to fabricate a high quality, energy-saving and blue-hazard free OLED. The candle light emitting OLED can exhibit an approaching 90 color rendering index or an above 90 natural light spectrum resemblance index (SRI), with a power-efficiency at least 300 times that of candles at color-temperature below 2,000K. Most importantly, it shows a much lower melatonin suppression impact than candles, based on the same luminance level. It is indicated that the candle light-style OLED is physiologically-safer than candles, and the safest among all electricity-driven lighting sources ever.

Biography:

Nasser Peyghambarian received his Ph.D. in solid-state Physics from Indiana University in 1982. He then joined the University of Arizona where he is currently a Professor at the College of Optical Sciences and the Department of Materials Science & Engineering. He is an adjunct professor at the Electrical Engineering Department at UC San Diego, and the Director of the NSF Engineering Research Center for Integrated Access Networks. Additionally, he is the Chair of Photonics and Lasers at the University of Arizona and Director of the Photonics Initiative. He has over 500 publications in refereed journals and more than 25 patents.

Abstract:

Nonlinear optics (NLO) including second harmonic generation, fourth harmonic generation, optical parametric processes, difference frequency generation, and Raman effects would allow generation of new laser frequencies over a wide spectrum. Our recent results in developing fiber lasers sources covering uv to mid-IR will be summarized.

Biography:

Angelo Angelini has completed his PhD at the age of 28 years from Polytechnic of Turin. During his studies, he spent 6 months at Columbia University, Biomedical Engineering department. He is currently a research fellow at Polytechnic of Turin. He has published more than 10 papers in reputed journals.

Abstract:

An overview of recent results on photon management through surface modes on purely dielectric multilayers is provided. Diffraction as well as guidance and confinement of Bloch Surface Waves (BSW) are shown, and a particular focus on near-field coupling of emitters with BSW modes is provided. The ability of modifying the radiation pattern of emitters by employing nano structured surfaces is gaining growing attention in a variety of applications related to nanophotonics, such as few-molecule and quantum emitters detection. In this framework, Surface Plasmon Coupled Emission (SPCE) has demonstrated to be an effective way to address this issue. Generally, plasmonic-based mechanisms exploit a near-field transfer of energy from the emitters to plasmonic modes. However, the main drawback in using plasmons on metal is represented by ohmic losses, producing broad resonances and absorption of useful signal. An effect similar to SPCE occurs on properly tailored one dimensional photonic crystals sustaining BSWs. Due to the very low absorption coefficient of the 1DCP materials, the BSW-coupled fluorescence can propagate for longer distances as compared to plasmons. In addition, the use of dielectric structures offers interesting advantages such as a wide spectral tunability (from UV to IR); the possibility to have either TE or TM polarized BSW and higher Q-factors. By properly structuring the surface of 1DPC, light coupled to BSWs can be manipulated in several ways (e.g. diffracted, guided, and focused). In particular, spontaneous emission of emitters lying on the surface of 1DPC can be efficiently beamed out in arbitrary directions with low divergence.

Biography:

Dan Sporea received the MS degree in Electronics Engineering from “Politehnica” University, Bucharest, Romania, in 1972 and a PhD degree in Physics Engineering from the Institute for Atomic Physics, Magurele, Romania, in 1992. He is currently heading the Laser Metrology and Standardization Laboratory, at the National Institute for Laser, Plasma and Radiation Physics (INFLPR), Magurele, Romania. For the last four years he acted as technical Deputy Director for a project focused on the development of a research infrastructure – the Center for Advanced Laser Technology, which includes a PW-class laser. Within this project he was in charge with the set up of the Photonics Investigations Laboratory. He coordinated several research projects for the European Fusion Program and over 15 national projects related to laser metrology, radiation effects in devices and materials, optical fiber sensors for critical installations. He holds one American patent and over 20 Romanian patents. He co-authored several book chapters on optical information processing, optoelectronics, optical fiber and optical fiber sensors in radiation environments. He coordinated Romanian participation to intercomparisons projects organized by NIST, the Laser Centrum Hanover, and Physikalisch-Technische Bundesanstalt.

Abstract:

Optical fibre based sensors constitute an exciting alternative to classical optical and/or electric sensors as they provide several exceptional advantages: small dimensions; low mass and footprint; multiplexing capabilities (temporal, wavelength); immunity to various hazards (fire, explosions) and electromagnetic interferences; extended communication bandwidth; possibility to handle multi parameter distributed configurations with remote control. Of a special interest is the use of intrinsic or extrinsic optical fibre sensors under irradiation conditions, as their performances in such environments has to be evaluated in relation (i) to their radiation reliability (how well they keep their basic characteristics unaltered by the radiation-matter interaction) or (ii) to the way they can act as radiation detectors/monitors. As radiation detectors or monitors, optical fibre sensors found their use in niche application such as: particle accelerators, synchrotron installations, free electron lasers for scientific or industrial purposes (as transducers for dose rate, total dose, beam losses, beam profiling, and reconstruction of charge particle tracks); neutron, gamma-ray, beta ray distributed dosimetry; water and soil contamination monitoring. In the medical field, optical fibre sensors were applied in the dosimetry of ionizing radiation; dosimetry in computed tomography; sterilization of instrumentation. This talk describes different types of optical fiber based sensors for radiation monitoring and dosimetry. In the introduction various radiation effects on optical fibers and optical fiber based sensors will be presented and compared. The parameters of interest for these sensors such as: Sensitivity to radiation; energy dependence; recovery/ stability; dynamic range and linearity will be discussed. Our results on the use of such sensors (intrinsic or extrinsic) in medicine, particle accelerators or synchrotrons, nuclear waste management, and distributed radiation fields mapping will be introduced.

Biography:

Nasser Peyghambarian received his PhD in solid-state Physics from Indiana University in 1982, specializing in optical properties of semiconductors. He joined the University of Arizona in 1982 where he is currently a Professor at both the College of Optical Sciences and the Department of Materials Science & Engineering. He is an Adjunct Professor at the Electrical Engineering department at UC San Diego. He is Director of the NSF Engineering Research Center for Integrated Access Networks. He is also Chair of Photonics and Lasers at the University of Arizona as well as Director of the Photonics Initiative. His research interests include optical networks and optical communication, fiber optics, fiber lasers and amplifiers, organic photonics, 3D holographic display and 3D telepresence, nonlinear photonics, optical modulators and switches, laser spectroscopy, nanostructures and quantum dots.He is the Founder of TIPD, LLC and NP Photonics, Inc.

Abstract:

Nonlinear Optics (NLO) including Raman and optical parametric processes allow the generation of new frequencies. Our recent effort in the generation of new fiber laser sources in near IR and mid IR will be summarized.

Biography:

“Sebastian Rodriguez received the B.Sc. (2011) and the M.Sc. (2014) in Electronic Engineering in the Pontificia Universidad Javeriana, in Bogota, Colombia. He worked on Rohde & Schwarz as an Application Engineer on the Test and Measurement division. Now he is a Marie Currie fellow in the Department of Photonic Engineering of the Technical University of Denmark.”

Abstract:

There is an increasing demand for high capacity wireless communications technologies stemming from the requirement from 5G mobile wireless networking in combination with the proliferation of wireless devices affordable to a wider range of consumers. Moreover, the emergence of internet-of-things (IoT) is demanding too wireless connectivity to sensors and devices. In those scenarios wireless connectivity is much desired and it can be achieved by the use and or support of photonic technologies both for applications related to data transmission as sensing. This talk will review the demands and requirements for high capacity wireless data transmission links with capacities of 100 Gbps and beyond. We will present examples of signal generation, detection for such systems employing photonics technologies. We will also layout current research trends and open research challenges.

Biography:

J. J. Vegas Olmos received the B.Sc. and the M.Sc. in Telecommunications and Electronic Engineering, respectively, in 2001 and 2003. He obtained the Ph.D. degree from the Eindhoven University of Technology, The Netherlands, in 2006. He also holds a M.A. in East Asian Studies, a B.Ec. in Business Administration, and an MBA. He was a Research Fellow at Osaka University, Japan, from 2006 to 2008, and a Research Associate at the Central Research Laboratory, Hitachi Ltd. Since 2011, he is with the Technical University of Denmark, where he is an Associate Professor at the Department of Photonics Engineering.

Abstract:

Optical links using traditional modulation formats are reaching a plateau in terms of capacity, mainly due to bandwidth limitations in the devices employed at the transmitter and receivers. Advanced modulation formats, which boost the spectral efficiency, provide a smooth migration path towards effectively increase the available capacity. Advanced modulation formats however require digitalization of the signals and digital signal processing blocks to both generate and recover the data. There is therefore a trade-off in terms of efficiency gain vs complexity. Polybinary modulation, a generalized form of partial response modulation, employs simple codification and filtering at the transmitter to drastically increase the spectral efficiency. At the receiver side, polybinary modulation requires low complexity direct detection and very little digital signal processing. This talk will review the recent results on polybinary modulation, comprising both binary and multilevel signals as seed signals. The results will show how polybinary modulation effectively reduces the bandwidth requirements on optical links while providing high spectral efficiency.

Biography:

Abstract:

For decades, one of the expeditions of quantum physics has been to build a quantum computer that can process large-scale, challenging computational problems exponentially faster than classical computers. While scientists and engineers are progressing toward this target, almost every part of a quantum computer still needs noteworthy Research and Development (R&D). Current research is focusing on every angle of the quantum computer problem, including:
• innovative ways to generate entangled photon pairs,
• inventive types of gates and their fabrication on chips,
• superior ways to create and control qubits,
• novel designs for storage/memory buffers,
• effective detectors, and
• Creative ways to optimize them in various architectures.
Optimizing the waveguide geometry, integrated quantum optical circuits are constructed to realize single-photon quantum computing. The central elements for such circuits include sources, gates and detectors. However, a major missing function critical for photonic quantum computing on-chip is a buffer, where single photons are stored for a short period of time to facilitate circuit synchronization. As a significant step in the field, an all-optical integrated quantum processor is being developed at the National Institute of Quantum Computing (NIQC).
For fault-tolerant quantum computing, the speech will explore the frontier of current quests for quantum processing of ultra-high security, integrating the following enabling techniques including
• probabilistic Bayesian network,
• quantum filtering,
• Error Correction Code (ECC), and
• Riemannian geometry.

Biography:

Antonio Jurado-Navas received his M.S. degree (2002) and a Ph.D. degree (2009) in Telecommunication Engineering, both from the University of Málaga (Spain). He was the recipient of a Spanish Ministry of Education and Science scholarship (2004–2008). From 2004 to 2011, he was a Research Assistant at the Communications Engineering Department in the University of Málaga. In 2011, he became an Assistant Professor in the same department. Dr. Jurado-Navas has worked for different companies: Vodafone (2002-2004), Airzone (2008-2009), or Ericsson (2012-2015). Since 2015, he is a Marie Curie Fellow Postdoctoral Fellow at the Technical University of Denmark and member of the Atmospheric Optical Communications Group in the University of Malaga. His research interests include topics such as atmospheric optical communications, adaptive optics and statistics.

Abstract:

Recently, a new and generalized statistical model, called Málaga or simply M distribution, has been proposed to characterize the irradiance fluctuations of an unbounded optical wave front (plane and spherical waves) propagating through a turbulent medium under all irradiance fluctuation conditions in homogeneous, isotropic turbulence. Málaga distribution was demonstrated to have the advantage of unifying most of the proposed statistical models derived until now in the scientific literature in a closed-form and mathematically-tractable expression. Furthermore, it unifies most of the proposed statistical models for the irradiance fluctuations derived in the bibliography providing, in addition, an excellent agreement with published plane wave and spherical wave simulation data over a wide range of turbulence conditions (weak to strong). In this communication, reviews of its different features are discussed including a new interpretation and a physical interpretation of its parameters is provided. It is worth noting that the proposed expressions of this Málaga distribution together with their physical interpretation provide a very valuable tool for analyzing the effects of turbulence induced scintillation in atmospheric optical communication links under any turbulence conditions.

Biography:

Marcin Kowalczyk works as an Assistant Professor in the Institute of Telecommunications in the Warsaw University of Technology (WUT), Poland. He graduated the Faculty of Electrical Engineering, Automatic Control and Computer Science of the Kielce University of Technology and PhD studies at Faculty of Electronics and Information Technology at the WUT, where he received his PhD in 2010. His professional interests include optical communications, microwave electronics and database systems. He is author or co-author for more than 50 papers.

Abstract:

A light communications technology in a visible-spectrum, well-known as VLC, attracts an attention of many researchers, since last couple years. New regulations introduced by the management bodies at the world opened a gate for increasing the share in the global market illumination the light emitting diodes (LEDs), making them the most important kind of a light source, which will be used broadly at a near future. This fact is one of the most crucial reasons why with an introduction the VLC technology on the market the expectations related to it are so enthusiastic. Of course, the technology still needs a time to mature. Paradoxically, the concept of transmission in the visible-spectrum can find new applications during this time. One of them is a proposal of use the VLC link to a realization of Ethernet communication between devices forming a shared network. The article presents the results of initial investigations for an instance of such network where VLC is used as a base for realization optical wireless link path between two computers instead of cable connection or Wi-Fi. There is especially interesting that the LEDs were used in a double role. It means that some of the diodes are used as photo-detectors, not as light emitters.

Biography:

Prof. Mousumi Basu received her MSc in physics from Jadavpur University, India, in 1992, MTech in solid state technology in 1995, and PhD in physics in the area of fiber optics in 2000 from Indian Institute of Technology, Kharagpur, India. Since 2000, she has been a faculty member of physics in Indian Institute of Engineering Science & Technology, Shibpur, India. She has published several research papers in refereed journals and conferences. Her current research interest includes designing optical fibers in view of nonlinear pulse propagation and fabrication and characterization of optical nanofibers.

Abstract:

Propagation of optical pulses with different shapes in optical fibers has created tremendous research interests because of the potential applications in ultra high speed optical systems, quantum optics, high power lasers, supercontinuum generation. Nonlinear pulse reshaping towards Parabolic (PP), semi parabolic (SPP) and triangular (TP) pulses can be possible in optical fibers and it depends on fiber parameters such as dispersion, nonlinearity and gain; and also on pulse properties such as pulse energy, width and peak power. A Gaussian pulse propagating through a normal dispersion fiber amplifier, can be changed to a linearly chirped PP of self similar nature in presence of nonlinearity and thus it does not suffer from the deadly effects of optical wave breaking. Any pulse from a CW laser asymptotically converts into a PP independent of its initial shape when Raman fiber amplifier is used to provide gain. However use of erbium doped fiber amplifier (EDFA) may change the dynamics of pulse propagation. For EDFA the dipole relaxation time and gain dispersion term control the pulse propagation by modifying the nonlinear Schrödinger equation. It is also seen that the evolved pulse may be parabolic or nonparabolic; depending on the repetition rate of the input laser source, initial pulse parameters as well as fiber parameters. Some nonparabolic pulses are very close to PP, which are termed as semiparabolic pulse. Those SPP can be again stabilized to PP using two stage fiber system. At the same time prechirping technique in a normal dispersion fiber is also helpful to generate stable TP which are used as sawtooth pulses in optical signal processing.

Biography:

Vincenzo Spagnolo received the PhD in physics in 1994 from University of Bari. Since 2003, he works as assistant Professor of Physics at the Technical University of Bari. He has been a visiting researcher at the Rice University (TX) in 2009 and 2010. His current research interests include quantum cascade lasers, spectroscopic techniques for real-time device monitoring, fiber optics, optoacoustic gas sensing. He is author of 2 patents and has published more than 70 journal papers. He has given more than 30 invited presentations and co-authored over 100 presentations in the international conferences and workshops.

Abstract:

The detection and quantification of trace gas concentrations are of considerable importance for a number of applications, such as environmental monitoring, industrial process control analysis, combustion processes, detection of toxic and flammable gases, as well as explosives. One of the most robust and sensitive trace-gas optical detection techniques is the quartz enhanced photo-acoustic spectroscopy (QEPAS). QEPAS is an alternative approach to photoacoustic detection of trace gas, utilizing a quartz tuning fork (QTF) as a sharply resonant acoustic transducer to detect weak photoacoustic excitation with a compact and relatively low-cost absorption detection module.
I will report an overview of the latest developments in QEPAS trace-gas sensor technology employing quantum cascade laser sources, such as the realization of mid-IR fiber coupled sensor systems, QEPAS sensors operating in the THz spectral range and intracavity-QEPAS sensors, realized by coupling to a QTF in a build-up optical cavity. Results on the design and realization of new QTFs with different geometries, providing significant enhancements of optoacoustic generation efficiency, will be also reported.

Biography:

Sven Höfling received his diploma degree from the University of Applied Physics and his PhD degree from Würzburg University. During his scientific carrier he has moreover been affiliated with the Fraunhofer Institute of Applied Solid State Physics, Stanford University, the University of Tokyo and the National Institute of Informatics in Tokyo. He is holding personal chairs in physics at the University of Wuerzburg, Germany, and at the University of St Andrews, Scotland and he is running the 550 m2 clean room facility Gottfried-Landwehr-Laboratory for Nanotechnologies. Dr. Höfling published about 250 papers in peer reviewed scientific journals and he delivered more than 50 invited talks at international conferences.

Abstract:

20 years after their first reference interband cascade lasers (ICLs) have become a mature and competitive semiconductor laser source in the mid-infrared region. The carrier rebalancing concept that was introduced in 2011 drastically improved the performance. As a consequence the wavelength window that is accessible for ICLs operating at ambient temperatures could be extended. For GaSb based ICLs cw-emission at room temperature could be achieved up to a wavelength of 5.6 µm. As the need for thicker claddings at longer wavelengths makes the growth of the superlattice claddings increasingly difficult and limits the heat dissipation, a plasmon waveguide structure with highly doped InAs-layers grown on InAs-substrates is typically used for ICLs emitting beyond 6 µm. At cryogenic temperatures plasmon waveguide based ICLs have shown emission up to 10.4 µm. Up to now there has not been an attempt to explore the lower wavelength limit of ICLs. Here we present cw emission of a GaSb based ICL emitting at 2.8 µm and room temperature pulsed operation of an InAs based plasmonic waveguide ICL up to 7.1 µm. Furthermore, we show single mode emitting ICLs with distributed feedback gratings emitting between 2.8 and 5.2 µm.

Biography:

Kimberley C Hall completed her PhD at the University of Toronto in 2002, followed by Postdoctoral studies at the University of Iowa. Since 2004, she has been a Faculty Member in the Department of Physics and Atmospheric Science at Dalhousie University and holds a Canada Research Chair in Ultrafast Science. At Dalhousie University, she directs a research group focused on ultrafast spectroscopy and quantum control in semiconductor materials.

Abstract:

Low-temperature-grown GaAs is currently being applied in a wide range of ultrafast optoelectronic devices, including fast photodetectors, and photoconductive components for both CW and time-domain THz photonics. The attractive properties of this material for such applications, including a large dark resisitivity and short photocarier lifetime, stem from the introduction of excess As in the form of AsGapoint defects during growth at low temperatures.A comprehensive understanding of the ultrafast response of LT-GaAs is essential to optimize device performance as well as to further applications of related low-temperature-grown semiconductors including III-Mn-V spintronic materials and LT-InGaAs. We have applied femtosecond four-wave mixing to study the coherent carrier response of LT-GaAs. These experiments reveal clear signatures associated with the free-carrier-interband transitions, the Urbach band tail, and the fundamental exciton. The latter two features are inaccessible using linear spectroscopy due to strong band-edge broadening tied to optical transitions associated with the As impurity band, a contribution we show to be suppressed in the four-wave mixing response due to the enhanced sensitivity to the optical joint density of states relative to linear spectroscopy and the sensitivity of the signal to many-body effects. The spectral structure of the Urbach band tail revealed in our experiments provides a direct measure of the effective band gap in LT-GaAs, and will provide input into theoretical models of the electronic structure in the presence of As-related disorder.

Biography:

Mythili Prakasam obtained her PhD from Anna University Chennai, India in 2009. She joined Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB)-CNRS, Pessac-33608, France in 2009 and has been working till date at ICMCB. She has published more than 30 papers in reputed journals.

Abstract:

Tremendous efforts over the past six decades has led to huge progress in advanced solid state and fiber lasers for energy and power scaling. In the present scenario, solid state crystal lasers though are ideal for applications, primarily in terms of compactness and user friendly, these types of crystals are difficult to be grown due to the high temperature growth issues, which limit size and quality. Though transparent ceramics have low transmittance than single crystals has higher mechanical strength and large flexibility to fabricate into complex shapes. Transparent ceramics processing with nano sized ceramic powders and advanced densification technology provides an alternative approach to overcome the disadvantages/ limits of conventional single-crystal growth methods.It would be much easier to elaborate polycrystalline ceramics with a full densification state and a homogeneous chemical composition under sintering temperature much lower than its melting point with a relative low cost and size flexibility. We at ICMCB have demonstrated successfully the fabrication of transparent ceramics of both cubic and non-cubic crystal structured materials by combining the high sinter ability of nano crystalline (nc) powders with the rapid densification rates characteristic of spark plasma sintering (SPS). Further single crystals obtained by hydrothermal technique with their principle and optical applications will be discussed. An overview of transparent ceramics and single crystals obtained by high pressure techniques for various optical applications will be discussed in detail.

Biography:

Debasruti Chowdhury has completed her Master of Science from Bengal Engineering and Science University, Shibpur, India. Now she is pursuing her PhD work in Indian Institute of Engineering Science and Technology, Shibpur, India in the area of fibre optics. She has published research papers in peer reviewed international journal as well as in national and international conference proceedings.

Abstract:

At present many researchers have found research interests on some special type of optical pulse waveforms other than Gaussian or secant pulses. Specially, triangular pulses have potential applications in optical signal processing, wavelength conversion, time domain add-drop multiplexing and many more. Literatures reveal that the combined action of self phase modulation and normal dispersion on pre-chirped Gaussian pulse can lead to the generation of triangular pulse within a short range of fibre length. In this work we present the numerical results of the generation of triangular pulses through a normally dispersive highly nonlinear fibre (ND-HNLF). Here we investigate the effects of input power, input energy as well as the chirping parameter on the stability of triangular pulse generation. An input Gaussian pulse with an initial chirp is fed into the ND-HNLF and its propagation through the fibre is studied by solving the nonlinear Schrodinger equation (NLSE) numerically. To check whether the output pulse has reached the triangular zone the Structure Factor is calculated. The proposed ND-HNLF is used also as a fibre amplifier i.e. the effect of gain on the optimum length of triangular pulse generation and its stability is studied here. It has been noticed that controlling the input power of the chirped Gaussian pulse can lead to create triangular pulses for a stability length ~ 50 m in transient-state propagation regime. For active ND-HNLF the stability length is increased sufficiently in the steady state domain. This approach of creating triangular intensity profile is suitable for a range of several photonic device applications.

Biography:

Nikolay A Nosyrev has graduated from Baltic State Technical University «VOENMEH» named after D.F. Ustinov with a degree in laser technologies. He is the process engineer of laser technologies in shipbuilding laboratory, JSC “Shipbuilding and Shiprepair Technology Centre”. He takes an active part in research and development of hybrid laser-arc welding technologies for ship’s hulls production. At present he is working on the dissertation for a candidate of sciences degree. He has presented a number of articles and reports in reputed journals and international conferences.

Abstract:

Implementation of new technologies on leading shipbuilding plants is a characteristic feature of the modern shipbuilding. Integrated application of laser technologies is a way to increase shipbuilding production quality. Shipbuilding and Shiprepair Technology Center is a leading design and engineering center in Russian shipbuilding sector. SSTC has a wide range of laser equipment and takes an active part in development and application of laser technologies for shipbuilding. Over 40 years SSTC develops and supplies shipbuilding industry with gantry thermal cutting machines. The latest project is the laser cutting machine based on fiber lasers with power from 1 to 3.5 kW. The gantry laser cutting complexes “RITM” characterized by high reliability and ease of maintenance have shown themselves to advantage at Russian shipbuilding and engineering enterprises. There are several robotized complexes among the advanced developments of SSTC, including program-controlled complexes for three-dimensional laser cutting and welding. Programmable equipment for laser welding of heat-exchangers and welding in hard-to-reach places was designed. SSTC also developed flat sections manufacturing technology based on application of laser technologies. The sample of automated welding and assembly line for sections up to 12 meters by 12 size using flow positional method and other technological solutions never applied before in world shipbuilding industry was created. Approval of Russian Maritime Register of Shipping for typical hybrid laser-arc welding process of plates and profiles of ship’s hull structures with laser cut groove preparation was obtained. Development and application of laser technologies allows achieving new level of productivity and production of structures in shipbuilding and mechanical engineering.

Biography:

Michael Fiddy received his Ph.D from the University of London, and was faculty member at Kings College from 1979-1987. He moved to the University of Massachusetts Lowell in 1987 where he was ECE Department Head from 1994 until 2001. In January 2002 he was appointed the founding director of the Center for Optoelectronics and Optical Communications at UNC Charlotte. He stepped down from this position in 2010 and has been site director for the NSF Industry/University Center for Metamaterials which began in 2011. He has been the editor-inchief of the journal Waves in Random and Complex Media since 1996 and is Deputy Editor of OSA’s recently launched Photonics Research Journal. He currently serves on the OSA Board of Directors and the Advisory Board of the Optoelectronics Industry Development Association (OIDA). He is a fellow of the OSA, IOP and SPIE.

Abstract:

This presentation focuses on man-made composites or metamaterials which exploit resonant behavior in their constituent elements or meta-atoms to reduce the overall refractive index. We illustrate the potential use of such materials as index values drop below unity and approach zero in various applications as well as their use as a possible ink for nanoprinting which is one of our motivations. We have investigated distributions of nanoparticles of various seizes and concentrations made from transparent conducting oxides. Their scattering and coupling interactions provide an enhanced or resonant response that can lower the index of the bulk material. These interactions are not included in traditional effective medium models which typically underestimate the actual index values. Our particles of choice are aluminum-doped zinc oxide which can be grown with known concentrations of Al in order to control their plasma frequency or permittivity zero-crossing. Their sizes and concentrations can also be controlled. The polarization dependence of these media has been investigated and will be reported here. Also new simulations and experimental results will be shown.

Biography:

Nicholas Kioussis has completed his PhD from University of Illinois at Chicago and postdoctoral studies from West Virginia University. He is the founder and director of the W. M. Keck Computational Materials Theory Center at California State University Northridge. He has published more than 150 papers in reputed journals in the areas of electronic structure calculations, multiscale modeling of defects, spin transport in magnetic tunnel junctions, and defect calculations in Type II Super Lattices.

Abstract:

The InAs/GaSb and InAs/InAsSb type-II strain-layer superlattices (T2SLS) are of great importance and show great promise for mid-wave and long-wave infrared (IR) detectors for a variety of civil and military applications. The T2SLS offer several advantages over present day detection technologies including suppressed Auger recombination relative to the bulk MCT material, high quantum efficiencies, and commercial availability of low defect density substrates. While the T2SLS detectors are approaching the empirical Rule-07 benchmark of MCT’s performance level, the dark-current density is still significantly higher than that of bulk MCT detectors. One of the major origins of dark current is associated with the Shockley-Read- Hall (SRH) process in the depletion region of the detector.
I will present results of ab initio electronic structure calculations of the stability of a wide range of point defects [As and In vacancies, In, As and Sb antisites, In interstitials, As interstitials, and Sb interstitials] in various charged states in bulk InAs, InSb, and InAsSb systems and T2SLS. I will also present results of the transition energy levels. The calculations reveal that compared to defects in bulk materials, the formation and defect properties in InAs/InAsSb T2SLS can be affected by various structural features, such as strain, interface, and local chemical environment. I will present examples which demonstrate that the effect of strain or local chemical environment shifts the transition energy levels of certain point defects either above or below the conduction band minimum, thus suppressing their contribution to the SRH recombination.

Biography:

Zhang Yong-gang received B.S. degree from Nanjing Institute of Posts and Telecommunications, China in 1982. He was a worker during 1975-1978, and a teacher during 1982-1984. He gained M.S and Ph.D. degrees from Shanghai Institute of Metallurgy (now named Shanghai Institute of Microsystem and Information Technology), Chinese Academy of Sciences in 1987 and 1996 respectively, and served here since 1987. His research interests include III-V semiconductor optoelectronic materials, devices and applications. He had been a full-professor at the State Key Laboratory of Functional Materials for Informatics since 1996, and supervised 25 Ph.D. and M. Sc. students there.

Abstract:

In addition to antimony containing materials on GaSb substrate, the mature epitaxial growth and processing technology, as well as higher thermal conductivity, makes the antimony-free materials on InPa good candidate to cover 2-3 µm wavelength range. For InxGa1-xAs QW lasers the wavelength can be tailored to this range by increasing the indium content in the QWs, whereas significant strain is introduced and confinement become poor, so the structural design, control of epitaxial quality and suppression of dislocations become main concern. For PDs of longer wavelength, the indium content should also be increased, a quite large lattice mismatch need to be relaxed through suitable buffer. In this talk, our efforts on InP-based antimony-free QW lasers and InxGa1-xAs PDs are reviewed. For lasers, novel triangular QW was used to increase the lasing wavelength while restricting the strain. Digital alloy technology was used to form triangular QW during the MBE growth. CW lasing from 2.0 to 2.4 µm at room temperature has been achieved. To extend the emission wavelength longer, metamorphic scheme was employed on In0.8Al0.2As template to produce a virtual substrate with larger lattice constant than InP for InAs QWs. CW lasing wavelength up to 2.73 μm have been demonstrated. The cutoff wavelengths of PDs have been shifted from 1.7 µm up to 2.9 µm. The PDs using InAlAs buffer and cap layers with wider bandgap were grown and demonstrated, and p-on-n ort n-on-p PD configuration was applied. The buffer schemes and growth conditions were optimized.

Biography:

Bruno Bureau is a Professor, obtained his PhD on "Local order investigations in fluoride glasses by multinuclear solid state NMR" at the University of Maine in 1998. In 1999, he joined the Glass and Ceramic Laboratory at the University of Rennes for a position of Assistant Professor. He became full-Professor in 2006 and he has been the Co-Supervisor of 18 PhD. He is the Authors or Co-Authors of more than 140 papers and about 50 invited talks in the field of non-oxide glasses, infrared sensing, optical fibers, material and glass science, deposited patents, wrote 4 chapters of book. He received 5 awards, among which the Yvan Peychès award from the French Academy of Sciences in 2009. He has co-founded the DIAFIR Company in 2011 and is now appointed to the “Institut Universitaire de France”.

Abstract:

The glass-forming ability of chalcogens combinations has been known for several decades, but, compared to oxide glasses, especially silicates; this class of vitreous materials is just emerging in particular in order to shape optical fibers. The main attention paid to these materials relies on their large optical window extending in the mid-infrared giving access to molecular fundamental vibrational modes shifted far in the IR. This exceptional transparency, associated with suitable viscosity/temperature dependence is a favorable context to seize the opportunity to develop innovative optical fibers for mid-infrared sensing. Such fibers have been used in various frames with different final users in biology with INSERM, medical diagnosis with the Public City Hospital in Rennes, for CO2 detection to strike against the global warming or for the Darwin mission of the European Space Agency (ESA). For each application, a special strategy is implemented in material science and optical fiber engineering. The talk will be devoted to the description of the last achievements in the field. A focus will be proposed on the new pure-telluride glasses which enable to expand the spectral working window further in the mid-IR until 20 µm.

Biography:

Jae Su Yu received the Ph.D. degree in optoelectronic engineering from Gwangju Institute of Science and Technology, Republic of Korea, in 2002. He joined the Center for Quantum Devices, Northwestern University, Evanston, IL, as a Postdoctorial Fellow in Oct. 2002, where he worked on the fabrication, packaging, and characterization of quantum cascade lasers. Since joining in Sept. 2006, he is a Tenured Professor in the Department of Electronic and Radio Engineering, Director of the Institute for Laser Engineering, and Kyung Hee Fellow, Kyung Hee University, Republic of Korea. He has authored or co-authored more than 240 journal papers. His research interests include solar cells, light-emitting diodes, optical sensors, miro/nanostructures, nanophotonics, phosphors, etc.

Abstract:

Over the past few years, light managements including antireflection, light scattering, and light trapping have been shown to be a promising approach to develop various optoelectronic and photonic devices and to improve their performance for optical sensing and energy harvesting applications. As an alternative of conventional antireflection layers, there has been much research on the nano- or micro-textured surfaces with efficient antireflection and light-scattering properties. Low-dimensional metal oxide nanostructures are very promising for photodetectors and sensors because of their excellent physical and chemical properties. On the other hand, to enhance light harvesting, antireflective structured polymers, for example, polycarbonate, polydimethylsiloxane, polymethyl methacrylate, polyurethane, etc., have been explored. Also, these structures can be employed in light-emitting diodes to enhance the light extraction efficiency. For this reason, an increasing attention has been recently given to functional nano/microstructured materials including nanowires/nanorods, nanophotonics, microtextures and biomimetic materials. For the nano/microstructures, various fabrication methods using growth/synthesis as well as dry/wet etching via nano/micro patterning were developed. Therefore, optical design and analysis of nano/microscale structures are required for potential applications of various devices such as solar cells, photodetectors, light-emitting diodes, and sensors. In this talk, I present the fabrication and optical properties of inorganic and organic nano/microstructures for light harvesting and sensing applications. Also, to enhance the device performance, the geometrical and optical structures were designed and analyzed based on theoretical calculations. By applying these structures to optoelectronic and photonic devices, their characteristics were evaluated.

Biography:

Ewa Schab-Balcerzak is a professor at the University of Silesia in Katowice, Poland, and head of the department of Polymer Chemistry. She is also a a professor at the Polish Academy of Sciences in the Centre of Polymer and Carbon Materials in Zabrze. She received her PhD in 1999 and DSc in 2010 from Silesian University of Technology in Gliwice and from Warsaw University of Technology, respectively. In 1999, she was a visiting researcher at LEMP/MAO at the University of Montpellier, France. From 2010 to 2002 she was a Post-Doctoral Research assistant in the Department of Organic and Polymeric Materials in Tokyo Institute of Technology in Japan. In 2003, she worked at Fraunhofer Institute of Applied Polymer Research in Golm, Germany. Her experience and main research interests are in the design, synthesis, and characterization of new processable polymers and low molecular weight compounds for optoelectronic and photonic applications. Her scientific achievements contain over 110 papers in refereed journals, a few book chapters and contributed to over 100 communications in conferences. She is a reviewer for prestigious journals and editorial board member of a few journals.

Abstract:

During the past few decades, processable organic semiconductors have been intensively studied due to their potential for a broad range of application in optoelectronics including e.g. organic light emitting diodes (OLEDs), organic photovoltaics (OPVs) and organic field effect transistors (FETs). Although remarkable progress has been made, the development of highly efficient and long-term stable optical and electrical devices is still a challenge. The milestones which stimulated the development of organic optoelectronics will be presented. After a brief introduction concerns the kinds of organic semiconductors together with their advantages and disadvantages, typical thiophene based materials will be discussed. The second part of this talk will be focused on unconventional compounds containing thiophene structures. Special emphasis will be put on compounds bearing imine linkages and/or aromatic imide rings. Thus, (poly) azomethines, (di) imides, azomethine naphthaldiimides, azines and others selected bithiophene derivatives reported in the literature also by our research group will be presented. The selected, mainly luminescence, electrochemical and photovoltaic properties of mentioned compounds making them an attractive for optoelectronics will be reported.

Biography:

Sergey Sadofev received his Ph.D. in 2009 from Humboldt-Universität zu Berlin and completed postdoctoral studies at Paul-Drude-Institut für Festkörperelektronik. Since 2012 he is a post-doctoral Research Associate at Humboldt-Universität zu Berlin. He has authored or coauthored more than 40 papers in the international journals. His recent work concerns ZnO-based hetero-structures and transparent conductive oxides for use in optoelectronics and plasmonics.

Abstract:

The interaction of metals with electromagnetic radiation gives rise to collective charge excitations called surface plasmon polaritons (SPPs). The potential of these coupled light-matter states for creating nano-scale photon-based circuits is the core of what is summarized today by the term "plasmonics". We will show that strongly n-type ZnO is an excellent plasmonic material in the infrared spectral range. Using molecular beam epitaxy, we are able to generate free carrier concentrations of almost 1021 cm-3 by Ga-doping of ZnO without significant deterioration of the crystal perfection. In this way, a metallic dielectric function is formed with a negative-to-positive crossover of the real part tunable from mid infrared up to telecommunication wavelengths. The losses are at least one order of magnitude lower than for traditional metals. Fabrication of epitaxial multilayer structures with different doping level enables the formation of novel SPP dispersions that can be engineered in a unique way. In particular, SPPs at metal/metal-type interfaces exhibit finite frequencies in the long-wavelength limit, in marked contrast to metal/dielectric SPPs. Coupling of SPPs at adjacent interfaces allows for almost arbitrarily shaping of their dispersion curves for achieving, e.g., phase matching for nonlinear processes or even anomalous dispersion. Further, we resonantly couple these SPP states to molecular vibrations and observe a profound change of the molecular line shape from absorptive to dispersive and even anti-resonance behavior when adjusting the resonance detuning. Moreover, hybridization of cavity photons and surface plasmon polaritons is observed defining novel routes for achieving and controlling stimulation phenomena in plasmonic systems.

Biography:

Sergiy Korposh joined University of Nottingham as a Lecturer in Electronics, Nanoscale Bioelectronics and Biophotonics in 2013. Since 2002 his research work has been devoted to the development and fabrication of chemical sensors based on a range of sensing platforms modified with functional nano-materials for various applications. He spent 8 years in Japan, as a Researcher and later as a Lecturer, where he worked mainly on the development of various facile methods for the preparation of advanced functional nano–materials. He has published over 50 peer-reviewed journal and conference papers, book contributions and holds a number of patents.

Abstract:

Optical techniques are considered as powerful tools for the development of chemical and biological sensors, covering a wide range of applications. Sensing techniques based upon the use of optical fibre devices to probe the optical characteristics of nanomaterials that exhibit changes in their optical properties upon exposure to targeted chemical species are particularly attractive, due to their potential high sensitivity, selectivity, the ready ability to multiplex arrays of sensors, and the prospect for remote sensing. The variety of different designs and measurement schemes that may be employed using optical fibres provides the potential to create very sensitive and selective measurement techniques that can be deployed in real environments. The use of optical fibre sensors is finding increasing acceptance across a range of industrial sectors, with interest being driven by features of the technology that offer advantages over conventional measurement approaches in niche applications. The presentation will discuss the development of fibre optic chemical sensors modified with the sensitive materials and introduce methods used for the deposition of the sensitive layers based on layer-by-layer adsorption and molecular imprinting techniques. Examples of the practical applications of the developed fibre-optic chemical sensors in bio-medical field will be provided.

Biography:

Dr. Leburton joined the University of Illinois in 1981 from Germany, where he worked as a research scientist with the Siemens A.G. Research Laboratory in Munich. In 1992, he held the Hitachi LTD Chair on Quantum Materials at the University of Tokyo, and was a Visiting Professor in the Federal Polytechnic Institute in Lausanne, Switzerland in 2000. He is involved with research in nanostructures modeling and in quantum device simulation. His present research interest encompasses non-linear transport in quantum wires and carbon nanotubes, and molecular and bio-nanoelectronics. He is author and co-author of more than 300 technical papers in international journals and books.

Abstract:

In this talk, we discuss the onset of sharp resonances exhibited by hot carriers in graphene under the influence of a DC and a-c fields in the presence of spatially and temporarily modulated scattering. These resonances occur when the period of the a-c field corresponds to the time taken by quasi-ballistic carriers to drift over a spatial scattering period, provided the latter is shorter than the distance taken by carriers to emit an optic phonon. Such system can be achieved with inter-digitated gates energized with an a-c bias on graphene layers. Gate separation and fields to achieve ballistic transport would result in resonances in the terahertz range, with the generation of higher harmonics characterized by large Q-factors, which are tunable with gate spacing, and well suited for THz detection.

Biography:

Luisa Torsi is professor at the University of Bari and elected vice-president of the European Material Research Society. She received her PhD in 1993 from the University of Bari and was post-doctoral fellow at Bell Labs (USA). In 2010 she was awarded with the Hedrick Emanuel Merck prize for analytical sciences. Her principal scientific contributions are in the fields of advanced materials and electronic devices mostly employed for sensing applications.. Torsi has more than 200 scientific products, including papers published in Science and in the Nature family journals, gathering over 7000 citations with a HI of 41 (Google scholar).

Abstract:

The energies involved in weak chiral interactions occurring between odorant binding proteins (OBPs) and carvone enantiomers are evaluated, down to a few KJ/mol, by means of a water-gated organic field-effect transistor (WGOFET) whose Au-gate is modified with a porcine-OBP (pOBP) self-assembled monolayer. The output current measured is dependent on the concentration of the analyte and pM concentrations can be detected. The binding curves also are significantly different between the two enantiomers. The modelling of the two curves allows the energies associated with the OBP-carvone complexes formation to be independently extracted, from the very same set of data. From the dissociation constants the standard free-energy the complex formation at the electrode is derived, while the threshold voltage shifts gives information on the electrostatic component. This approach, representing a unique tool to quantitatively investigate low-energy bio-chemical interactions, is rather general as it relies on the relative dielectric constants of the protein-SAMs and of the organic semiconductors being much lower than that of water. The role of the OBPs in the olfaction system is still under debate and the detection of neutral odorant species at the pM level by means of a WGOFET adds relevant pieces of information to the understanding of the odor perception mechanism at the molecular level.

Biography:

Ching-Fuh Lin obtained the BS degree from National Taiwan University in 1983, MS and PhD degrees from Cornell University, Ithaca, NY, in 1989 and 1993, respectively, all in electrical engineering. He is now the Director of Innovative Photonics Advanced Research Center (i-PARC) and a joint distinguished Professor in the Graduate Institute of Photonics and Optoelectronics, Graduate Institute of Electronics Engineering, and Department of Electrical Engineering at National Taiwan University. His major research area is in photonics, including organic-inorganic composites for light-emission devices and solar cells, single-crystal Si thin-film solar cells, Si-based photonics, and physics in broadband semiconductor lasers and optical amplifiers. He is a Fellow of IEEE, a Fellow of SPIE, Member of Asia-Pacific Academy of Materials, and a member of OSA. He has published over 160 journal papers and 460 conference papers and holds more than 60 patents. He is also the sole author of two books. He obtained the Distinguished Research Award and several Class A Research Awards from National Science Council of Taiwan, ROC, and the Outstanding Electrical Engineering Professor Award from the Chinese Institute of Electrical Engineering.

Abstract:

A novel nanotechnology for environmentally benign as well as efficient white light generation is developed. Compared to conventional phosphors that overly rely on rare-earth elements (REEs), this proposed nanotechnology is REE free and is instead based on the integration of II-VI semiconductor nanoparticles and polymeric materials. ZnO and ZnS:Mn nanoparticles are combined with poly (9,9-di-n-hexylfluorenyl-2,7-diyl) to create efficient warm-light-emissive nanocomposites. The resultant nanocomposites encompass three different photon-generating routes, which can lead to blue, green and orange emissions, respectively. White light thus can be directly generated from the nanocomposites as pumping by commercial UV- or blue-LED. Moreover, a wide tunability of color temperatures ranging from below 3000K to 6000K, which embraces both candle light and white light, is achievable by the nanocomposite. A warm-white light emission with above 90% high quantum efficiency has also been demonstrated under the commercial UV-LED excitation. Additionally, we successfully explore an innovative technique to synthesize II-VI-based nanoparticles without quantum-confinement effect. The prepared nanoparticles can exhibit a strong absorption at 453 nm, which well fits the wavelength of commercial blue-LEDs (450-460 nm), and efficiently convert blue light to brightly orange light. The proposed nanoparticle-based technology can serve as a promising solution not only to the health issues involved in current blue-LED-YAG lighting systems, but also to the eco-friendly affordable efficient-lighting technology.

Biography:

Nolwenn Huby has completed her PhD at the age of 26 years from University of Bordeaux (France) on OLEDs fabrication and optimization. Then she performed Postdoctoral studies on integrated hybrid memories from Materials and Devices for Microelectronics laboratory in Milan (Italy). She is Associate Professor at the Optics and Photonics department of the Institute of Physics of Rennes, France, and is working on organic integrated photonics. She has published 30 papers in reputed journals.

Abstract:

In the field of nanophotonics, the understanding of optical phenomena related to sub-wavelength guiding in 1D-nanostructures is a fundamental interest for devices down-scaling. We present theoretical and experimental investigation of light propagation in original passive and active organic nanotubes. For this, polymer nanotubes has been designed and developed by the template wetting method. To characterize their optical behaviour and in particular the sub-wavelength propagation, numerical and experimental tools have been developed. Modelling phenomena propagating in these nanofibers was performed by the numerical FDTD method. The effects of the geometry of these nanotubes and nanowires have been investigated. In particular, the effect of the diameter (outer and inner diameter for nanotubes) on the propagation behaviour, (energy distribution, losses) as well as the effect of the substrate has been determined. Experimentally, two types of nanofibers were studied. First, direct injection into passive nanofibers of SU8 polymer was performed through a micro lensed optical fiber. A striking result is the assessment of optical losses measured by the cut-back around 1.25 dB/mm for nanotubes of external and internal diameters respectively 240 nm and 120 nm. This appears very competitive compared to other systems currently envisaged for integrated nanophotonics. Second, active polymer nanofibers (polyfluorene PFO) embedded in a wave guiding polymer were elaborated and appeared to be an efficient design for a nano-source.

Biography:

Damian C Onwudiwe completed his PhD in 2011 from University of Fort-Hare and Post-doctoral research studies in North-West University, South Africa. He is presently a Senior Lecturer at the Mafikeng campus of the North-West University, where he conducts research on the controlled synthesis and manipulation of materials' physical and chemical properties using different approaches. He has published more than 35 papers in international journals, and also serves as Editorial Member of different journals of repute.

Abstract:

Semiconductors nanoparticles have been extensively studied due to their potential applications and novel properties. Although different methods have been reported for the synthesis of these semiconductor materials, more environmental-friendly approaches continue to attract attention. Here, we focus on the II–VI types of semiconductor nanoparticles as they represent ideal systems for dimension-dependent properties. In this report, nanosecond laser was used to effect the decomposition of metal complexes, and also the nucleation process of nanoparticles in polymer solutions. CdS, ZnS, and ZnO nanoparticles were successfully prepared. The effect of change in concentration of the polymer solutions on the properties of the nanoparticles was studied. The morphology, structure, and optical properties of the nanoparticles were investigated. An increase in concentration of the polymer solution influenced the morphology of the nanoparticles, and also resulted in a decrease in the band gap energy of the nanoparticles. These are ascribed to the increase in adsorption centres and reduction in the coalescent process of the nanoparticles in the polymeric matrix.

Biography:

J.K.H. Hoerber has completed his PhD 1986 from Technical University of Munich and did postdoctoral studies at Ludwig Maximilians University Munich with Theodor Haensch. He worked at IBM Research Rueschlikon, Max Planck Institute for Medical Research and the European Molecular Biology Laboratory. His first professorial appointment was at Wayne State University Medical School in 2001. Since 2005 he is Professor of Nanobiophysics at the University of Bristol and serving as an editorial board member of JMR.

Abstract:

The development of the field of nano-optics during recent years, and the knowledge acquired meanwhile about the interaction of light with nano-structures opens up new ways for remote sensing even inside live cells. The Photonic Force Microscope (PFM) able to manipulate and track nano-particles with nano-meter precision can provide the instrumental framework. Depending on size and shape, metal nano-structures have plasmon resonances at distinct frequencies. With a tunable laser adjusted to their resonance the light scattering cross-section increases significantly allowing to track small particles down to a size of about 5 nm. Furthermore, metal particles can be used as “nano-lenses” concentrating the electromagnetic field of light at their surface. In this way, only fluorophores in close vicinity will be excited. For fluorescence measurements inside a cell this provides the same advantage of very low background fluorescence, as total internal reflection fluorescence (TIRF) excitation provides close to a surface allowing single molecule fluorescence measurements with nano-meter resolution everywhere inside cells. An even more exciting possibility lays in the identification of single molecules without labeling by measuring a Raman “fingerprint”. Certain geometric features of metal nano-particles can enhance the Raman signal of a molecule by a million times when in contact and so nano-meter sized particles become chemical sensors with single molecule sensitivity. In this way metal nano-particles within a PFM provide a new analytical tool with single molecule sensitivity and nano-meter position resolution with huge potential for cell-biological studies on regulation and transport processes within living cells.

Biography:

Edik U Rafailov received his PhD degree from the Ioffe Institute. In 2005 he established new group and in 2014 he and his Optoelectronics and Biomedical Photonics Group moved to Aston University. He has authored and co-authored over 350 articles in refereed journals and conference proceedings. He coordinated a €14.7M FP7 FAST-DOT project – development of new ultrafast lasers for Biophotonics applications. Currently, he coordinated the €11.8M NEWLED project aims to develop a new generation of white LEDs. He also leads a few others projects funded by FP7 EU and EPSRC. His current research interests include high-power CW, ultrashort-pulse lasers; generation of UV/visible/IR/MIR and THz radiation, nano-structures; nonlinear and integrated optics; Biophotonics.

Abstract:

In the last decades, progress in compact semiconductor based laser technologies has brought to science and industry an enormous number of new applications. Such laser systems which were mostly utilized in the communication and other industries are now becoming adopted in biomedicine and related fields. Here we would like to outline some of the most promising applications where compact laser diode based light sources in UV/visible, near and mid infrared wavelength ranges are being used in biophotonics, particularly focussing on CVDs, diabetes, and cancer diagnostics and photo treatment.

Biography:

Ehsan Vaghefi is a bioengineer who has developed the biomedical imaging methods (MRI, micro-CT and laser ray-tracing) to image the physiological optics of the ocular lens. He obtained his PhD in 2010 from the Auckland Bioengineering Institute (ABI) at the University of Auckland. In that project he used MRI techniques to visualize circulating ion and fluid fluxes in the lens and to develop a 3D finite element model that encapsulates lens structure and function. He has continued this work as a Post Doctoral Research Fellow within the Molecular Vision Lab, while contributing to the teaching of physiological optics to undergraduate Optometry students. Jason Turuwhenua is currently a Research Fellow at the Auckland Bioengineering Institute, University of Auckland, New Zealand, with a joint appointment in the Department of Optometry and Vision Science, where he teaches physiological optics. His research interests include optics, computer vision and image processing, with a particular emphasis on understanding how engineering approaches can be applied for clinical use. Previous work has included research on numerical methods for reconstructing corneal topography, and modeling the optics of the eye using ray-tracing.

Abstract:

Age-related changes to the optical properties of the ocular lens are the leading causes of presbyopia and cataract. We know little about how the optical properties of the lens are established and maintained at the molecular and cellular levels during the natural aging process. The ocular lens has an inherent Gradient of Refractive Index (GRIN) which we have recently shown is altered by perturbing lens physiology. In order to study the changes of GRIN with aging, we have constructed a laser ray-tracing system to allow us to measure the optical properties of organ cultured lenses, while manipulating the underlying physiology of the lens. Our present system design includes two Single Reflex Lens (SLR) cameras and a highly precise illumination stage, which has enabled us to introduce the laser beams onto the lens at any desired angle and off-center offsets. Our current setup has laser beam angle measurement accuracy of ±0.2Ëš and image acquisition in-plane resolution of 30μm and pixel back-projection error of less than 0.3 of a pixel size. Also, our current calibrated setup is capable of measuring lens surface profile to an accuracy of <40µm, using SLR cameras which we have validated using in-vitro topography measurements from a number of bovine lenses. We have also implemented a BIONKO customized incubation chamber to control and manipulate the physiology and accommodative state of the imaged lens. By precisely controlling the laser beam delivery and tracing its path through the lens, mapping the lens’s surface profile while controlling its physiological and mechanical states, we are studying the effects of aging on the lens’ optical properties.

Biography:

Xuewen Shu has completed his PhD at the age of 27 years from Huazhong University of Science and Technology (HUST), China. He worked as a senior scientist at Aston University & Indigo Photonics Ltd, UK during 2001-2013. He is currently a full professor at HUST. He has published more than 150 papers in reputed journals and conferences. His research interests include fiber gratings, optical fiber communications, fiber lasers and optical sensors.

Abstract:

A fiber grating is an optical fiber for which the refractive index in the core has a periodic or quasi-periodic perturbation profile. Fiber gratings can be created with various laser sources such as UV lasers (photosensitivity is required) and femtosecond lasers (no photosensitivity is required). Fiber grating technology has attracted considerable research interests in past two decades since it has wide applications in optical communications and sensing. Due to their natural compatibility, fiber gratings can serve as a perfect platform for all-optical signal processing in optical fiber communication systems. They can directly process optical signals in optical fiber without the need for coupling/re-coupling alignments required by bulk-optics or chip based devices, thus provide a low-loss, stable, cost-effective and ultra-fast solution for optical signal processing. Moreover, they can offer very strong design flexibility to achieve almost arbitrary spectral characteristics. Here we will report our recent progress on all-optical signal processing based on fiber grating technology. We will present fiber gratings designed and fabricated for optical differentiation, optical pulse shaping, optical format conversion and so on. The gratings were designed with layer-peeling method and fabricated with UV direct-writing technique. The performances of their use as optical signal processors were also evaluated experimentally.

Biography:

Valerio Pruneri is an ICREA Industrial Professor, Corning Inc. Chair and group leader at the Institute of Photonic Sciences (ICFO). Previously he worked for Avanex, Corning, Pirelli, and the Optoelectronics Research Centre (University of Southampton). He has more than 30 patent families, 60 invited talks and 300 refereed papers. He serves on the European QEOD board, the advisory board of ACREO Fiber Optic Centre, VLC Photonics and Medlumics SL. He received the Philip Morris Prize for Scientific and Technological Research, the Pirelli Research Fellowship, the IBM Faculty Award, the Corning Inc. Professorship and the Duran Farell Prize for Technological Research.

Abstract:

Ultrathin materials and nano-structuring are becoming essential for the functionalization of optical surfaces. In the talk we will show how ultrathin metals can be exploited to create competitive transparent electrodes while graphene and phase change materials to modulate the optical response. Ultrathin metals can also be used to create nanostructured surfaces through mass scalable dewetting and etching techniques. We will also provide examples of applications enabled by these materials and techniques, including efficient high speed electro-optic modulators, indium-free light emitting diodes, solar cells and easy-to-clean display screens.

Biography:

Henri-Jean M. Drouhin graduated from the École Polytechnique, France in 1979 and obtained his Ph.D. degree with habilitation (Doctorat d’État) in 1984 from Paris-Sud University, Orsay, France. He has made major contributions to the field of semiconductor spin physics and spintronics. He is Associate Professor, Vice President of the Physics Department, and researcher (Physics and Chemistry of Nano-objects group leader) at Irradiated Solids Lab., (CNRS & CEA/DSM/IRAMIS, École Polytechnique). He was the Dean of Studies for the École Polytechnique from 2000 to 2008 and Deputy Vice- President for Research from 2008 to 2014. He is the author of more than 80 scientific publications as well as being decorated with the Chevalier Legion of Honour (French Pres., 2002) and being made an Officer of the National Order of Merit (French Pres., 2009). He was elected as a Fellow of SPIE in 2007.

Abstract:

We report on theoretical investigations and k.p calculations of carrier tunneling in model systems and heterostructures composed of exchange-split III-V semiconductors, involving spin-orbit interaction. The media are possibly separated by thin tunnel barriers. In a 2x2 exchange-split band model, we prove that, when spin-orbit interaction is included in the conduction band of two exchange-split semiconductors, the electrons can be differently transmitted with respect to an axis orthogonal to both the axis normal to the interface and the magnetization direction. The transmission asymmetry between +k// and -k// incidence is shown to reach100% at some points of the Brillouin zone corresponding to a totally quenched transmission for given incidence angles. We establish the universal character of the transmission asymmetry, independent on the spin-orbit strength and material parameters. Particular asymmetry features are reproduced by more complete 14x14 bands calculations involving interband coupling. On the other hand, calculations performed in the valence-band of model heterostructures and including tunnel barriers in both 6x6 (without inversion asymmetry) and 14x14 k.p band models more astonishingly highlight the same trends in the transmission asymmetry which is shown to be related to the difference of orbital chirality and to the related branching of the corresponding evanescent states responsible for tunneling current. In both cases (electrons and holes), the asymmetry appears to be robust and persists even when only a single electrode is magnetic. This paves the way to new functionnalties with spinorbitronics devices.

Biography:

Pascale Roy performed her PhD research in LURE, Orsay France and received her PhD in Physics from Université Laval, Canada. She was a Postdoctoral fellow at Los Alamosin 1986-89 and was hired as CNRS Researcher at LURE, Orsay France in 1989. She became CNRS Senior Scientist in 1992 and moved her research activity to Synchrotron Soleil in 2004. Her research is focused on the implementation of synchrotron radiation based Infrared and THz beamline, new spectroscopic methods and the development of associated spectroscopic studies. She is currently in charge of the AILES (Advanced Infrared Line Exploited for Spectroscopy) at SOLEIL. The AILES group currently investigates the physical properties of confined material, the optical properties of condensed matter, the edge radiation and coherent sources, the rovibrational spectroscopy of molecules of interest for atmospheric and astrophysics. She is responsible for the Condensed Matter Physical Chemistry group at Synchrotron SOLEIL.

Abstract:

Recently, an unprecedented high power source of THz radiation was made scientifically available: coherent synchrotron radiation (CSR). This radiation produced from relativistic electron bunches of picoseconds duration opens up new territory in the THz range with intensities up to 4 orders of magnitude higher than previous sources. In this mode of operation (200 electron bunches of 100µA each), the total emitted power is 2 mW and its stability is sufficient to perform bunch per bunch spectroscopic measurements based on Electro Optics sampling technique. These promising results clearly lead to the development of new applications including terahertz spectroscopy at the nsec rate without the need for a pump probe technique, as well as ultra-high resolution spectroscopy based on heterodyne mixing technique. We will show how these new techniques have been demonstrated on the AILES beamline of synchrotron SOLEIL.

Biography:

Ephraim Greenfield has an M.Sc. from The University of Chicago and a PhD from Hebrew University in Physics. He is one of the founders of Ophir Optronics, was the R&D manager and is presently the CTO of the company. He has developed many devices in the area of laser measurement and has 5 patents in the area.

Abstract:

The trend in lasers used for material processing has been to higher and higher powers that today have reached as much as 100kW and above. Measuring the power and beam quality of such high powers is an increasing challenge. Ophir has developed a power meter capable of measuring up to 120kW of power and a beam profiler capable of measuring the beam profile at the focal spot at similar powers. The power meter is a relatively compact device carefully designed to spread the beam in a manner so as not to exceed the damage threshold of the materials used. The beam profiler uses Rayleigh scattering to measure the beam profile with no physical contact at all with the beam. We will describe in detail how these devices operate.

Biography:

Tomofumi HAMAMURA was born in 1984 in Tokyo, Japan. He was a research fellow of the Japan Society for the Promotion of Science (JSPS) from 2011-2013. He received a PhD degree from The University of Tokyo in 2014. In April 2014, he became a post-doctoral fellow at The University of Tokyo. In September 2014, he joined the research group of University of Bordeaux as a visiting researcher of LIA-Next PV project between French institutes and The University of Tokyo. My current interests include the development of large π-conjugated organic molecules for organic electronics.

Abstract:

Dye-sensitized solar cells (DSSCs) have widely attracted much attention as promising candidates for low-cost next-generation solar cells. For the improvement of the power conversion efficiency of DSSCs, it is important to utilize near-infrared (NIR) light and to induce efficient charge-separation at the interface between dyes and TiO2. The charge-separation process is known to be affected by the adsorption geometry of dyes on the TiO2 surface. In this study, we focused on ethynyl-linked porphyrin trimers as NIR-light harvesting dyes, and investigated the effect of the adsorption geometry of the trimers on the photovoltaic properties of the DSSCs. Some trimers which are different in the number and position of anchoring groups were synthesized for controlling their adsorption geometry. Photo-anodes were prepared by immersing TiO2 electrodes into DMF solution of these compounds containing deoxycholic acid as co-adsorbent. The difference in the number of anchoring groups drastically changed the adsorbed amount of the trimers on the TiO2 surface. On the other hand, the difference in the position of anchoring groups was found to affect not only the adsorbed amount of the trimers, but also charge-separation efficiency. Among these compounds, the trimer with anchoring groups in the long-axial direction showed the highest IPCE value in NIR region (47% at 840 nm). In this talk, we will discuss the difference in the photovoltaic properties of the DSSCs using these compounds in detail.

Biography:

Vivek Raj Shrestha completed BE in Electronic and Communication Engineering from Nepal in 2010 and he has been pursuing his integrated masters and PhD program in Electronic engineering at Kwangwoon University, Seoul, Korea since 2011. He has worked on integrated optical devices and free space optical modules. His current research interests include the nano-structured devices, serving as the visible optical filters and their application to communication devices, sensors and display devices. He has published more than 12 papers in reputed journals including Nanoletters, Scientific Reports, and Optics Express etc.

Abstract:

Nanostructured spectral filters enabling dynamic color tuning are regarded to be saliently attractive for implementing ultra-compact color displays, holographic imaging, information encoding, and anti-counterfeiting. Realization of polarization-induced dynamic color tuning via one dimensional periodic nanostructures remains as a challenge due to their inherently low transmission for transverse-electric polarization. We report on highly efficient dynamic subtractive color filters incorporating a dielectric-loaded one dimensional Aluminum grating, providing a continuum of customized color in accordance with the polarization of incident light. The dynamic spectral filtering in the visible regime is attributed to selective suppression in transmission spectra originating from plasmonic resonance for a metal-dielectric interface and guided-mode resonance for a metal-clad dielectric waveguide occurring at their characteristic wavelengths for transverse-magnetic and -electric polarizations, respectively. Taking into account that the transmitted color output is initially determined contingent upon periods of a metallic grating, we manufactured several devices with different periods so as to accomplish a broad palette of color with transmission beyond 80%, inclusive of cyan, magenta and yellow, by tailoring the polarization. Moreover, the proposed filters conspicuously feature a dual-mode operation of both transmissive and reflective configurations. Thanks to the functional material of Al, which is advantageous in terms of low cost, high durability, and mass producibility, the proposed device is predicted to offer strong potential for immediate commercial applications.

Biography:

K M Tanvir Ahmmed is a PhD student at McGill University; he is working under Prof. Kietzig’s supervision in Biomimetic Surface Engineering laboratory. He has been working on micro/nano structure fabrication on different materials with femtosecond laser, and he published peer-reviewed journal articles on this topic.

Abstract:

Femtosecond laser micromachining is increasingly investigated as a new technique for micro/nano structure fabrication because of its applicability to virtually all kinds of materials in an easy one-step process that is scalable. Various parameters (such as fluency, number of pulses, laser beam polarization, wavelength, incident angle, scan velocity, number of scans, and processing environment) have a strong influence on the result of the micromachining process. We propose the fluency and pulses-per-spot (F-PPS) and accumulated fluency profile (AFP) models to group, characterize and optimize the microstructures observed on metallic surfaces from single scan machining. Furthermore, these models are also useful to predict the machining result on polymeric surfaces. However, multiple scans of surfaces cannot be described by these models. We present how another formation mechanism seems to be responsible for the formation of randomly distributed elliptical cones observed at very low fluency irradiation and multiple scans.