Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 3rd International Conference and Exhibition on Lasers, Optics & Photonics Valencia, Spain.

Day 2 :

  • Track 3: Optoelectronics
Speaker

Chair

Michael A Fiddy

UNC Charlotte, USA

Speaker

Co-Chair

Nicholas Kioussis

California State University, USA

Session Introduction

Michael A Fiddy

UNC Charlotte, USA

Title: Low Index Optical Materials

Time : 09:00-09:20

Speaker
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.

Speaker
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.

Zhang Yong-Gang

Chinese Academy of Sciences, China

Title: InP-based antimony-free lasers and photodetectors in 2-3 µm band

Time : 09:40-10:00

Speaker
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.

Speaker
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.

Speaker
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.

Break: Coffee Break 10:40-11:00 @ Foyer

Ewa Schab-Balcerzak

University of Silesia, Poland

Title: Unconventional thiophene materials for optoelectronics

Time : 11:00-11:20

Speaker
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.

Sergey Sadofiev

Humboldt-Universität zu Berlin, Germany

Title: ZnO-based plasmonics

Time : 11:20-11:40

Speaker
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.

Sergiy Korposh

The University of Nottingham, UK

Title: Optical fibre chemical sensors: Bio-medical application

Time : 11:40-12:00

Speaker
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.

  • Track 4: Optical Communications and Networking
    Track 7: Quantum Science and Technology
    Track 9: Applications and Trends in Optics and Photonics
Speaker

Chair

Dan Sporea

National Institute for Laser, Plasma and Radiation Physics, Romania

Session Introduction

Dan Sporea

National Institute for Laser, Plasma and Radiation Physics, Romania

Title: Ionizing radiation dosimetry with optical fibers

Time : 12:00-12:20

Speaker
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.

Juan Sebastián Rodriguez Páez

Technical University of Denmark, Denmark

Title: Photonics technologies for 100 gbps wireless communications

Time : 12:20-12:40

Speaker
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.

J.J. Vegas Olmos

Technical University of Denmark, Denmark

Title: Polybinary modulation for bandwidth limited optical links

Time : 12:40-13:00

Speaker
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.

Break: Lunch Break 13:00-13:45 @ Aqua Restaurant
Speaker
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.

Speaker
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.

Mousumi Basu

Indian Institute of Engineering Science & Technology, India

Title: Nonlinear pulse dynamics in passive and active optical fibers

Time : 14:25-14:45

Speaker
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.

Vincenzo Spagnolo

Università e Politecnico di Bari, Italy

Title: QEPAS- New developments in quartz enhanced photoacoustic gas sensing

Time : 14:45-15:05

Speaker
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.

Sven Hoefling

Universität Würzburg, Germany

Title: Single mode interband cascade lasers

Time : 15:25-15:45

Speaker
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.

Speaker
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.

Mythili Prakasam

Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB)
France

Title: Optical applications of single crystals and transparent ceramics fabricated by high pressure process

Time : 16:05-16:25

Speaker
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.

Debasruti Chowdhury

Indian Institute of Engineering Science and Technology Shibpur, India

Title: Generation of triangular optical pulses through a normally dispersive highly nonlinear fibre

Time : 16:25-16:35

Speaker
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.

Nikolay A Nosyrev

JSC Shipbuilding and Shiprepair Technology Center, Russia

Title: Shipbuilding application of laser equipment and technologies

Time : 16:35-16:45

Speaker
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.

Break: Poster Session 17:05-17:35 @ Foyer