Day 3 :
- Main Hall Sessions
Location: Conference Hall: The Five Spot Room
Chair
Dongsun Seo
Myongji University, Korea
Co-Chair
Taiji Sakamoto
NTT Access Network Service Systems Laboratories, Japan
Session Introduction
Yutaka Fukuchi
Tokyo University of Science, Japan
Title: Technique of optical frequency comb generation from a bismuth-based harmonically mode-locked fi ber laser
Time : 08:30-08:55
Biography:
Yutaka Fukuchi received his BS and MS degrees in Electronics Engineering from Tokyo University of Science, Japan in 1998 and 2000, respectively and completed his PhD degree in Electronics Engineering from University of Tokyo, Japan in 2003. In 2003, he joined the Department of Electrical Engineering, Tokyo University of Science. Since 2009, he has been an Associate Professor in this department. From 2013 to 2014, he was a Visiting Research Fellow with the Department of Photonics Engineering, Technical University of Denmark. His research interests are nonlinear optics and their applications.
Abstract:
Optical frequency comb generators can off er several attractive applications such as wideband multi-wavelength lasers, ultra-short pulse generation, coherent optical waveform syntheses, ultra-fast signal processing, high resolution spectroscopy and optical frequency reference. High stability, high coherence, high effi ciency, low noise, low cost, wide bandwidth and spectral fl atness are commonly required for those applications. Among many potential comb sources, harmonically mode-locked fi ber lasers are a popular solution owing to their abilities such as wavelength tunability, short pulse width, small timing jitter and high repetition frequency in the gigahertz region. However, since the harmonically mode-locked fi ber lasers usually employ silica-based erbium-doped fi bers as the gain media, the range of the wavelength tunability is limited to either the conventional wavelength band or the longer wavelength band. Furthermore, it is generally diffi cult for each frequency comb component generated by the harmonically mode-locked fiber lasers to have the same intensity. In this paper, we review a technique for producing a tunable and fl at frequency comb from a 10 GHz bismuth-based harmonically mode-locked fi ber laser. Th e output characteristics are as follows. Th e center wavelength can be tuned from 1535 nm to 1585 nm. Th e comb spectrum can be fl atly broadened up to 2.4 nm (300 GHz) with 30 comb lines. Th e spectral width and the pulse width can be tuned from 0.23 nm to 2.4 nm and from 3.0 ps to 20.1 ps, respectively. Th roughout the entire tuning ranges, this laser can maintain stable bit-error-free mode-locking operation within a received power deviation of 3.0 dB.
Taiji Sakamoto
NTT Access Network Service Systems Laboratories, Japan
Title: Randomly-coupled multi-core fi ber for long-haul optical MIMO transmission system
Time : 08:55-09:20
Biography:
Taiji Sakamoto received his BE, ME and PhD degrees in Electrical Engineering from Osaka Prefecture University, Osaka, Japan in 2004, 2006 and 2012 respectively. In 2006, he joined NTT Access Network Service Systems Laboratories, NTT, Ibaraki, Japan where he has been engaged in research on optical fi ber nonlinear effects, low nonlinear optical fi ber, few-mode fi ber and multi-core fi ber for optical MIMO transmission systems. He is a Member of the Institute of Electronics, Information and Communication Engineers.
Abstract:
The capacity of conventional single-mode fi ber (SMF) that is widely used in the existing optical communication network is expected to be limited to around 100 Tbit/s owing to the non-linear eff ect of the optical fi ber. Space division multiplexing technologies using multi-core fi ber (MCF) or few-mode fi ber have been investigated for overcoming the capacity crunch of conventional SMF. MCF has multiple cores within a cladding and multiple signals can be transmitted in parallel by using multiple cores. One important parameter for MCF is spatial density, namely the number of spatial channels per unit area, since the cladding diameter of the fiber is limited to a certain value in terms of mechanical reliability. Recently, coupled MCF which has a low core pitch value between the cores compared to the non-coupled MCF has been investigated with the aim of improving the spatial density. In this paper, we review recent progress on coupled multi-core fi ber (MCF) technologies and advantages of using this type of MCF for optical MIMO transmission system. Finally we report our recent results for high spatial density randomly-coupled MCF with low modal dispersion characteristic, which is benefi cial for realizing long-haul optical MIMO transmission.
Jiaren Liu
National Research Council, Canada
Title: Phase noise analysis of InAs quantum-dot mode-locked semiconductor lasers
Time : 09:20-09:45
Biography:
Jiaren Liu has completed his PhD in 1993 from Nanjing University of Science and Technology and then completed his Post-doctoral studies from Texas A&M University and University of Toronto. He is a Senior Research Offi cer of National Research Council of Canada and an Adjunct Professor of Concordia University. He has published 50 more papers in reputed journals and other 70 more papers in conferences and seminars.
Abstract:
Phase noise or linewidth of semiconductor diode lasers is vital parameter for various applications in optical sensing and coherent communication. In this talk, phase noise of individual mode in InAs quantum-dot (QD) mode-locked lasers (MLLs) made by National Research Council of Canada were investigated both theoretically and experimentally. Under optimized mode-locked conditions, the minimum linewidth of individual modes is about 0.6MHz, 0.8MHz, or 0.9MHz achieved for the repetition rate of 11GHz, 25GHz, or 34GHz respectively. For MLLs with the above channel spacing, the linewidths of 10 or more laser modes can go down to 1.0MHz at least. Th e relevant experimental result is consistent and fi tted with the theoretical prediction which assumes zeromean Gaussian random processes for both common mode and un-common mode phase noises. Such low phase noise MLLs will be the suitable and cost-eff ective candidate for multiple wavelength applications in long-haul and data-center fi ber optical networks.
Sang-Rok Moon
Electronics and Telecommunications Research Institute, South Korea
Title: CFO compensation method for coherent optical OFDM system by electro-optic feedback
Time : 09:45-10:10
Biography:
Sang-Rok Moon has received his BS degree in Physics in 2008 and his PhD degree in Electrical Engineering in 2015 from Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea. He is working at Electronics and Telecommunications Research Institute (ETRI) from 2015. His current research interest includes, orthogonal frequency-division multiplexing (OFDM) and optical cummunisation in metropolitan/access network.
Abstract:
We investigate feasibility of carrier frequency off set (CFO) compensation method using optical feedback path for coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. CFO compensation is one of most important issues in OFDM system, since the CFO breakes orthogonality among OFDM subrarriers and it causes critical degradation in signal quality. In CO-OFDM, the CFO tends to be high because of laser instability. Th us wide CFO compensation range is essential. Recently proposed CFO compensation algorithms provide wide CFO estimation range. Th ey compensate CFO aft er anlog-to-digital convertor (ADC). Then, CFO compensation range is limited by sampling rate of the ADC. Th us, the sampling rate should be much higher than
CFO and/or data bandwidth. Because of high price of ADC, it is not aff ordable in practical CO-OFDM. To solve this problem, we propose a CFO compensation method having optical feedback path. Th e measured CFO is used to control local oscillator’s wavelength for CFO compensation. Since the CFO is compensated before ADC, the compensation range is not aff ected by the ADC. Residual CFO can be compensated by conventional CFO compensation methods. Th e feasibility of the proposed method is experimentally investigated. We showed that the practical CFO compensation range can be extended to the sampling frequency range, regardless of sampling rate of ADC. Although the proposed method is based on OFDM, the proposed method works in all coherent modulation formats with minor modifi cation.
Jair Adriano Lima Silva
Federal University of EspÃrito Santo, Brazil
Title: The infl uence of constant-envelope signals in coherent-detection optical OFDM systems
Time : 10:10-10:35
Biography:
Jair Adriano Lima Silva received his BS, MS and PhD degrees in Electrical Engineering from the Federal University of Esp´ rito Santo (UFES), Vitória, Brazil in 2003, 2006 and 2011 respectively. In 2012, he joined the Department of Electrical Engineering of UFES. His research interest include optical fi ber communication, radio-over-fi ber, orthogonal frequency division multiplexing, passive optical communication network, visible light and powerline communiactions.
Abstract:
The resilience towards fi ber dispersion is the main attractive feature of orthogonal frequency division multiplexing (OFDM) signal processing in optical communications systems. Coherent-detection optical OFDM (CO-OFDM) posses many benefi ts that are critical for high data rate fi ber transmission systems. It is extremely robust against chromatic and polarization mode dispersions at the same time that it improves spectral effi ciency eliminating the need for a guard band between the optical carrier and the informationbearing signal. Furthermore, adaptive data rates with diff erent subcarrier mapping levels can be supported using soft ware-defi ned solutions. However, large peak-to-average power ratio (PAPR) of the inherent multicarrier signals is one of the main drawbacks in CO-OFDM systems, as it not only limits the resolution of digital-to-analog converters and power amplifi ers, but also reduces the tolerance to the nonlinearities introduced by Mach-Zehnder (MZM) optical modulators and optical fi bers. Several PAPR reduction techniques such as coding, tone reservation, clipping, peak windowing and partial transmit sequence, have been proposed in the literature. Th ese distinctly techniques provide diff erent degrees of eff ectiveness and tradeoff s that may include increased complexity, reduced spectral effi ciency and performance degradation. Recently, we proposed a PAPR reduction scheme based on constant envelope (CE) signals to improve the tolerance towards MZM modulators and fi ber nonlinearities in direct-detection optical OFDM systems. As a power effi cient technique, it reduced the PAPR to 3 dB using electrical phase modulation (PM). Aft er a successful experimental demonstration in direct-detection optical systems, this CE-OFDM technique was introduced in coherent detection systems as a suitable solution to the aforementioned problems. Unlike the approaches evaluated in the literature, the intermediate electrical constant-envelope signals of this solution were used to modulate the continuous wave laser source, employing a conventional one-branch MZM modulator. Th e infl uence of the electrical phase modulation index h in the performance of CE-OFDM in coherent detection optical systems was treated analytically and its range of validity examined by simulations. A compromise between h and subcarrier mapping was identifi ed according to diff erences in sensitivity related to non-linearities inserted by the MZM. We showed that the proposed scheme outperforms conventional coherent detection OFDM systems.
Reginaldo Barbosa Nunes
Federal Institute of EspÃrito Santo, Brazil
Title: A MAC layer protocol for a bandwidth scalable OFDMA PON architecture
Time : 10:50-11:15
Biography:
Reginaldo Barbosa Nunes has completed his PhD degree in Electrical Engineering from Federal University of Espírito Santo (2016), graduated in Electrical Engineering, Master’s in Computer Science and Computer Network Specialist. He is working as a Professor of higher and technical education at the Federal Institute of Espírito Santo from 1997. He has recently published more than 15 papers in reputed journals and international conferences, has been serving as reviewer member in several international periodics.
Abstract:
The need for high bandwidth networks driven by new digital services and technologies has culminated in the emergence of the new standards for passive optical networks (PONs) such as 10 Gigabit Capable PON (XGPON) recommended by the ITU-T (International Telecommunications Union - Telecommunications) and 10 Gigabit Ethernet PON (10G EPON) standardized by the IEEE (Institute of Electrical and Electronic Engineers), both provide rates up to 10 Gb/s per wavelength to the end user. More recently, the ITUT standard NGPON2 started using TWDM technology that provides rates up to 40 Gb/s, but for that, it needs to use four wavelengths. In this context, this we propose a PON architecture based on Orthogonal Frequency Division Multiple Access (OFDMA), capable to off er an effi cient bandwidth control with greater fl exibility and granularity in bandwidth allocation to the end users according their demand or required Quality of Service (QoS). Th e proposed architecture exploits the Orthogonal Frequency Division Multiplexing (OFDM) to provide transmission rates above 33 Gb/s per wavelength. Th e proposal considers a tree topology where each optical line terminal (OLT) is connected to at least one passive device splitter/combiner, provides multiple services for up to 32 optical network units (ONUs). Our work presents experimental results that demonstrate the feasibility of this physical infrastructure for passive optical network based on OFDM/OFDMA, suggests adaptations in the architecture and presents techniques for improving the system spectral effi ciency. In addition, it also describes the main recommendations to build a medium access layer in accordance with this proposal, named BS OFDMA PON (Bandwidth Scalable OFDMA PON).
Jianjun Yu
Fudan University, China
Title: Optimization of optical modulation formats for high-speed short-reach connection
Time : 11:15-11:40
Biography:
Jianjun Yu has completed his PhD in the year of 1996 from Beijing Univeristy of Posts and Telecommunications. He is the Professor of Fudan University. He has published more than 600 papers in reputed journals and has been serving as an Editorial Board Member of IEEE Photonics Journal, JLT and JOCN.
Abstract:
With the popularization of data centre and other bandwidth hungry inter-connect applications, the desired capacity of short reach optical network has exponentially increased to 400 Gbit/s or even more. Recent standardization eff orts for 400 G intradata center connections specify link lengths of up to 2 km. 8×56 Gb/s or 4x100 Gb/s could enable such 400 G networks. Relative to coherent detection. Intensity modulation/direct detection (IM/DD) is a good candidate in inter-connect due to its low cost. For 56 and up to 100 Gb/s signal generation, a few modulation formats or schemes, such as pulse-amplitude-modulation (PAM4), discrete multitone (DMT), duobinary and chirp-managed laser (CML) are proposed and experimentally demonstrated. However, considering cost, size and power comsuption, the modulation format should be optimized for diff erent networks to meet diff erent requirements. In this talk, we will discuss this issue how to optimize the modulation formats for diff erent optical networks?
Dongsun Seo
Myongji University, Korea
Title: Improvement of optical transmission capacity by data compression and amplitude/ phase/frequency 3-dimentional modulation
Time : 11:40-12:05
Biography:
Dongsun Seo has received his PhD degree in Electrical Engineering (Optoelectronics) from the University of New Mexico in 1989. In 1990, he has joined the Faculty of Myongji University, Korea, where he is currently a Professor in the Department of Electronics. From 2002 to 2004, he was with Purdue University, as a Visiting Research Professor in the School of Electrical and Computer Engineering. He has published over 70 journal articles and over 100 conference papers. His current research interests are in the areas of optical pulse sources, ultrafast optics, high-capacity optical communications, optical processing and photonics.
Abstract:
In this talk, we discuss novel schemes that improve signifi cantly the spectral effi ciency (i.e., channel capacity) of an optical access link. Firstly, an optical orthogonal frequency division multiplexing (OFDM) signal, which is encoded by multilevel quadrature amplitude modulation (QAM), is compressed using the proposed sampling scheme sampled at a lower than conventional Nyquist rate. At the receiver, the OFDM signal is recovered by a Bayesian compressive sensing (CS) technique. We show experimentally the spectral effi ciency improvement (i.e., data compression) up to <40% and <20% for 4-QAM and 16-QAM encoded OFDM waveforms, respectively. Secondly, we discuss channel capacity improvement by simultaneous modulation of amplitude, phase and frequency i.e., by combining frequency shift keying (FSK) and QAM. Th is 3-dimensional modulation so called NOFQAM, increases the modulation order dramatically by multiplying both the FSK and QAM orders. Unlike a conventional orthogonal FSK modulation, the FSK channels are overlapped in our non-orthogonal (NO) FSK modulation. Th erefore, the NO-FSK modulation increases the channel capacity at a fi xed channel bandwidth. For experimental verifi cation, we implement a 20-km optical access link, which transmits a 64-NOFQAM signal formed by combining both 4-FSK and 16-QAM. Th e symbol rate and FSK channel spacing are 200 M-symbol/s and 45 MHz, respectively. Comparing to a 200 M-symbol/s 16-QAM transmission, the suggested 64-NOFQAM transmission shows negligible increase in the occupied channel bandwidth and very small power penalty less than 0.5 dB. Finally, we apply the CS based data compression technique to the 64-NOFQAM signal and show greater than 50% of data compression.
- Technologies in Lasers, Optics and Photonics
Location: Conference Hall: Paramount Room
Chair
Jesse A Frantz
US Naval Research Laboratory, USA
Co-Chair
Eugene S Smotkin
Northeastern University, USA
Session Introduction
Jesse A Frantz
US Naval Research Laboratory, USA
Title: Anti-reflection surface structures on optics as an alternative to thin fi lm antirefl ection coatings
Time : 12:05-12:30
Biography:
Jesse A Frantz has received his PhD in Optical Sciences in 2004 from the Optical Sciences Center at The University of Arizona. He has been working as a Research Physicist at NRL since 2004 where his research is focused on microstructured optical surfaces and novel thin fi lm materials. He established and manages a Vacuum Deposition Cluster System Facility in NRL’s Optical Sciences Division used for a variety of projects including the fabrication of advanced, multi-layer thin fi lm devices for optical applications.
Abstract:
Anti-refl ection surface structures (ARSS) are nano-scale features patterned directly into an optical surface that are designed to have low optical refl ectance. Th ey have been demonstrated to increase the transmission of an optical surface to >99.9% and are an attractive alternative to traditional thin fi lm anti refl ection (AR) coatings for several reasons. They provide AR performance over a larger spectral and angular range and unlike thin fi lm AR coatings, they are patterned directly into the optic rather than deposited on its surface. As a result, they are not prone to delamination under thermal cycling that can occur with thin fi lm coatings and their laser damage thresholds can be considerably higher. In this presentation, we summarize results for ARSS on a variety of optical materials including silica, germanium, magnesium aluminate spinel and a variety of laser crystals. We discuss scale-up of the technique and describe results for ARSS with dimensions as large as 33 cm. We describe a surface modifi cation procedure that results in a superhydrophobic surface without a signifi cant decrease in transmittance. Finally, we show results for optical performance of ARSS on silica windows following sand and rain erosion testing showing that they are suitable for use in harsh environments.
Eugene S Smotkin
Northeastern University, USA
Title: A perspective on quasi-confocal operando Raman microspectroscopy of laminated polymer composite materials
Time : 12:30-12:55
Biography:
Eugene S Smotkin has completed his PhD from University of Texas at Austin. He is the Professor of Chemistry Northeastern University and CEO of NuVant Systems Inc., a premier electrochemical technology organization. He has published more than 80 papers in reputed journals and has 15 patents.
Abstract:
Steady state operando confocal Raman microspectroscopy of polymer electrolyte membrane fuel cell catalytic layers is challenged by thermal damage to the catalytic layer resulting from excessive luminescence within a focal point sampling region. Experimentalists must exclude catalyst material along the optical axis path or position the axis between (parallel) the catalytic layers. We demonstrated that operando non-confocal Raman microspectroscopy of a catalytic layer yields high quality spectra elucidating changes in the membrane ion exchange site local symmetry as the fuel cell transitions from open circuit to oxygen reduction potentials. We now explain how non-confocal microscopy enables steady state layer-by-layer spectroscopic profi ling with no thermal damage to “black” layers?
Takahiro Tsukahara
Tokyo University of Science, Japan
Title: Photo-induced flows relevant to laser-based droplet manipulations
Time : 13:45-14:10
Biography:
Takahiro Tsukahara has completed his PhD in the year 2007 from Tokyo University of Science. He is an Associate Professor of Department of Mechanical Engineering, Faculty of Science and Technology, Tokyo University of Science. He has published more than 37 papers in journal publications and 44 peer-reviewed proceeding papers. He has been serving as an Editorial Board Member of Advances in Mechanical Engineering. He has his expertise in Thermo-fl uid Dynamics, especially in Turbulent Transition and Flow Instability, and Computational Fluid Dynamics.
Abstract:
Non-invasive and non-contact manipulation of micro-scale droplet in air/liquid pool, which is relevant to Medical or Biological Engineering applications and chemical processes using lab-on-chip technology, has increasingly attracted attention in the fi eld of microfl uidics. Several techniques were proposed by utilizing a local variation of interfacial tension, because the eff ects of interfacial phenomena are dominant in microfl uidics relative to the inertia and buoyancy forces. In particular, laser-induced optical force may be used as a non-invasive and precise tool for droplet-based controls, but its force magnitude is limited on the order of a pico newton. Compared to the optical force, an optically-induced thermal Marangoni convection may provide a larger resultant force that provides the nano-newton order force. Th erefore, the photothermal Marangoni convection can be a powerful technique of on-demand bubble/ droplet handling in a micro-channel liquid. If allowed to change physical properties of surfactant solution liquid (e.g., azobenzene) in response to light, the cis-trans photoisomerization can be alternative non-invasive fl uid manipulation without adding heat. The cis-trans photoisomerization is a property that the cis and trans isomers are reversibly changed by light of a specifi c wavelength such as ultraviolet light. As the isomers of diff erent molecular structures are switched by light irradiation, physical properties such as the contact angle and interfacial tension are varied. We have performed direct numerical simulation of multi-phase fl ows of droplets that are accompanied by either photo-induced thermal Marangoni convection or cis-trans photoisomerization, in order to study quantitatively the force and mechanisms relevant to the laser-based droplet manipulation.
Robert Claude Gauthier
Carleton University, Canada
Title: Fourier-Bessel electromagnetic mode solver (and its inversion)
Time : 14:10-14:35
Biography:
Robert Claude Gauthier has completed his PhD in 1988 from Dalhousie University (Halifax, Canada). He is presently associated with the Department of Electronics at Carleton University, (Ottawa, Canada). He has published numerous papers primarily in the areas of optical fi ber sensors, optical levitation and trapping, photonic crystal and photonic quasicrys. His research interest now focus on numerical studies of optical resonator properties
Abstract:
Numerical simulations of electromagnetic phenomena provide the researcher and the component designer with a cost eff ective alternative to device manufacturing of prototypes. Techiques such as FDTD and FEM are commonly employed but hit up against speed and memory boundaries when structures are irregular or extend over all three coordinate axis. Th e talk will present a numerical technique, based on spectral analysis, which is suitable for numerical analysis of structures which present cylindrical and spherical geometries. Th e theoretical foundations of the numerical technique will be presented which takes its roots in Maxwell’s curl coupled equations rather than the usual wave equations. Th e eigenvalue matrix system properties were explored and symmetry techniques utilized to reduce the matrix order and tune “mode family” computations were highlighted leading to faster computation engines. Several computation examples will be presented indicating the suitability of the technique to obtain localized states in resonators, axially propagated fi elds in fi ber geometries and in spherical resonators. Recently, the numerical process has been inverted such that the material properties of an optical resonator and waveguide can be determined based on the user defi ned modal profi le and propagation properties selected by the designer theoretical details and numerical examples of the inverse process will close the presentation.
Holger Kreilkamp
Fraunhofer-Institute for Production Technology, Germany
Title: Glass optics replication in a digitalized production environment
Time : 14:35-15:00
Biography:
Holger Kreilkamp is Group Manager of “Optics” at Fraunhofer Institute for Production Technology IPT. He studied Mechanical Engineering specialized in Production Technology at RWTH Aachen University and received his Diploma degree in 2011. He got a second Diploma in Economics in 2012. Since then, he has worked as a Research Assistant at Fraunhofer IPT in the fi eld of Optics Manufacturing. His research focuses on technology development for glass optics production with special interests in replicative manufacturing.
Abstract:
Digitalization, adaptivity and networked production are dominant issues for state of the art manufacturing technologies and will continue to have a substantial impact on their advancement and development. Th is applies especially to complex process chains, characterized by multiple and non-trivial interdependencies, such as the replicative manufacturing of optical components. Ranging from the optical design, the FEM simulation and the mold manufacturing, down to the actual molding process and the assembly of the optical system, this process chain today reveals a low level of automation as well as insuffi cient (data-)standards and an inadequate information fl ow over the diff erent process steps. Since most of the single technologies are at the brink of technical feasibility, future components will need the ability to exploit the vast potential of interconnected and adaptive process chains. In order to promote and advance this transition in the fi eld of replicative optics manufacturing the Fraunhofer IPT has elaborated an innovative and comprehensive data solution concept, which has been implemented within the precision glass molding process (PGM). In a specially equipped glass molding machine, tailored sensor systems are collecting multiple data concerning the molding process, such as temperature, force and pressure profi les. Th is information is acquired in real time and serves the purpose of immediate visualization. Beyond this, all data are fed into a superior data backbone, allowing the reconstruction of an exact digital image of the component, highly valuable to adapt downstream and upstream processes, granting a glance on what future optics production in a totally digitalized production environment will look like.
Biography:
Baptiste MOT has completed his MSD in the year 2004 from the “conservatoire national des arts et métiers”. He works as a Research Engineer in an Astrophysic laboratory on several space telescopes.
Abstract:
PILOT is a balloon-borne astronomy experiment designed to study the polarization of dust emission in the diff use interstellar medium in our Galaxy at wavelengths 240 μm and 550 μm with an angular resolution of a few arc-minute. PILOT optics is composed an off -axis Gregorian type telescope and a refractive re-imager system. All optical elements, except the primary mirror, are in a cryostat cooled to 3K. We combined the optical, 3D dimensional measurement methods and thermoeslastic modeling to perform the optical alignment. I will present the system analysis, the alignment procedure, and fi nally the performances obtained during the second fl ight in March 2017.
T K Subramaniam
Sri Sairam Engineering College, India
Title: Laser technology to guide rainfall to a particular region
Time : 15:40-16:05
Biography:
T K Subramaniam has completed his PhD from Banaras Hindu University, India, specializing in Laser Spectroscopy. He is presently working as Professor of Physics at Sri Sairam Engineeering College, Chennai, India, teaching Under-graduate Physics at the college level for more than 20 years and also has six years of industrial experience. He has published more than 10 research papers in international journals of repute and is a Peer-Reviewer for the Optical Society of America (OSA) group of journals, besides serving in the Editorial Board of other reputed journals. Recently, he has presented a research paper at Olching, Germany, in November 2016.
Abstract:
Rain bearing clouds can be eff ectively guided to a specifi c region during monsoon or other seasons so that rainfall shall be equitably distributed without creating drought situations. Lasers sent into the lower troposphere region with power in Gigawatt ranges, suffi cient to create a temperature and pressure gradient and thereby creating a low pressure area in a specifi c region can invite rain bearing clouds in a region opposite to the heat and pressure gradient created by laser eff ects, so as to bring convective rainfall during a season. Pressure gradient describes the diff erence in air pressure between two points in the atmosphere or on the surface of the Earth. It is vital to wind speed, because the greater the diff erence in pressure, the faster the wind fl ows (from the high to low pressure) to balance out the variation. Satellite based monitoring system of cloud formations can be an eff ective guide to send laser beams in a direction towards the lower troposphere to create convective rainfall into another specifi c region.Laser beams are an attracted means of carrying concentrated power over distance. Hence, we choose a CO2 laser (λ=10.6 μm) whose power is not dissipated by interaction with any gas molecules and so diff raction will not take place. Th e beam stays coherent. Using up CO2 gas will reduce excess carbon emissions on Earth and bring down global warming also.Th us a temperature and a pressure diff erence created by a CO2 laser is enough to invite these clouds to move towards an opposite region and cause rainfall.
Ulrike Willer
Clausthal University of Technology, Germany
Title: Quartz-enhanced photoacoustic spectroscopy with electrical co-excitation
Time : 16:05-16:30
Biography:
Ulrike Willer has studied Physics at Christian-Albrechts University in Kiel and completed her PhD in the year 2001 at Clausthal University of Technology, Germany. She is Researcher at the Energy Research Center and Clausthal University of Technology. She has published more than 45 papers in reputed journals and has been serving as Progam Comittee Member for different scientifi c conferences. Her main research interest focuses on mid-infrared spectroscopy, photoacoustics and sensor design.
Abstract:
Photoacoustic spectroscopy relies on the temporally modulated energy input into a gas via absorption and the subsequent transfer into a sound wave that is measured. Th is transfer of energy from vibrational into translational modes is highly dependent on collision partners and linked relaxation rates. For quartz-enhanced spectroscopy (QEPAS) a micro-tuning fork is used as a transducer instead of a conventional microphone and the modulation of the excitation laser is done at the resonant frequency of the tuning fork for signal enhancement. However, it is not only possible to drive the tuning fork into oscillation by the photoacoustically generated acoustic wave but also by applying a modulated voltage. With these two diff erent driving forces, either applied simultaneously or subsequently, it is possible to gain more insight of the properties of the gas and the relaxation dynamics. Th is is especially valuable if the background gas and with it the collision partners, density, velocity of sound and relaxation rates change and a variation in signal cannot unambiguously attributed to a variation in concentration. It will be discussed how the photoacoustic interaction can be used to promote an originally electrically induced tuning fork oscillation or to fasten its fading, which enables the measurement of times rather than intensities.
S S Bayya
Naval Research Laboratory, USA
Title: Advanced IR glass and fiber technology
Time : 16:30-16:55
Biography:
S S Bayya received his PhD in Ceramics from Alfred University in 1992. He is a Research Scientist in the Optical Science Division at the Naval Research Laboratory (NRL) since 1994. His research interests include transparent ceramics, bulk optics and IR fi bers for various optical applications. He currently heads the Optical Materials section at NRL. He has >50 publications and holds 30 patents on optical materials.
Abstract:
Chalcogenide glasses, with their high refractive indices, low phonon energy, high nonlinearity and excellent transmission in the infrared (IR) region, make them ideal for incorporation into various civilian, medical and military applications such as infrared detectors, infrared lenses, planar optics, photonic integrated circuits, lasers and other non-linear optical devices. Chalcogenide glasses have also been widely studied for use in numerous potential optical fi ber applications such as fi ber lasers, amplifi ers, bright sources, as well as passive solid and hollow core IR fi bers for laser transmission. Although stable, low-loss chalcogenide based fi bers with minimum loss of <0.1 dB/m have been demonstrated, the chalcogenide based fi bers suff er from absorption and scattering losses mainly caused by impurities related to hydrogen, carbon and oxygen. Great eff orts have been made in reducing optical losses using improved chemical purifi cation techniques, but further improvements are needed in both purifi cation and fi berization technology to attain the theoretical attenuation. We have also designed and developed negative curvature, anti-resonant fi bers and demonstrated record low loss in the 9.75 – 10.5 μm range. In this paper, we review our recent eff ort in the development of low loss chalcogenide fi bers, by describing the various purifi cation methods and their impact on the optical fi ber loss and discuss the potential future outlook for these fi bers.
- Optical Physics | Optics and Lasers in Medicine
Location: Breakout Session:Paramount Room
Chair
A Seteikin
Amur State University, Russia
Co-Chair
Albrecht Lindinger
Freie Universitat Berlin, Germany
Session Introduction
A Seteikin
Amur State University, Russia
Title: Simulation of thermal reaction of biological tissues to laser-induced fluorescence and photodynamic therapy
Time : 08:30-08:55
Biography:
A Seteikin studied Physics at the Pedagogical University in Blagoveschensk. He has received his PhD in Physics in 2000. Currently, he is a Professor at the Department of Physics of the Amur State University in Blagoveschensk. His scientifi c background is in the fi eld of Laser - Tissue Interaction and Biophysics. In his work, he is using experimental and computational techniques. He has national and international collaborations in Physics and Life Science research.
Abstract:
The aim of this work was to evaluate the temperature fi elds and the dynamics of heat conduction into the skin tissue under several laser irradiation conditions with both a pulsed ultraviolet (UV) laser (λ=337 nm) and a continuous-wave (cw) visible laser beam (λ=632.8 nm) using Monte Carlo modeling. Finite-element methodology was used for heat transfer simulation. Th e analysis of the results showed that heat is not localized on the surface, but is collected inside the tissue in lower skin layers. Th e simulation was made with the pulsed UV laser beam (used as excitation source in laser-induced fl uorescence) and the cw visible laser (used in photodynamic therapy treatments), in order to study the possible thermal eff ects.
Izumi Nishidate
Tokyo University of Agriculture and Technology, Japan
Title: In vivo physiological imaging of biological tissues based on diffuse reflectance spectroscopy with an RGB camera
Time : 08:55-09:20
Biography:
Izumi Nishidate is working as an Associate Professor at the Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology. His research spans the interdisciplinary fi elds of Biomedical Optics with particular emphasis on the development of new techniques for medical measurement, imaging and diagnosis. His major areas of activity include diffuse refl ectance spectroscopy, spectral imaging, analysis of light transport in biological tissues and functional imaging of various organs. He received his PhD (2004) degree in Mechanical Systems Engineering, from Muroran Institute of Technology, Japan. He has authored/co-authored over 200 refereed journal articles, book chapters and conference/symposia proceeding articles.
Abstract:
Quantitative assessment of optical properties is important for monitoring metabolism, viability and physiological conditions of in vivo biological tissues. Diff use refl ectance spectra of living tissues refl ects the optical absorption spectra of biological chromophores (i.e., oxygenated hemoglobin, deoxygenated hemoglobin, bilirubin, cytochrome c oxidase, and melanin) and the light scattering spectra of tissues. Diff use refl ectance spectroscopy (DRS) has been widely used for the evaluation of chromophores in living tissue. Th e multispectral imaging technique is a useful tool for extending DRS to the spatial mapping of the chromophores and tissue morphology. Th is can be simply achieved by a monochromatic charge-coupled device (CCD) camera with narrowband fi lters and a white light source, which has been used to investigate the physiological conditions in living tissues such as blood perfusion, oxygenation state of hemoglobin, and melanin content. In clinical conditions, simpler, more cost-eff ective and more portable equipment is needed. Th e digital red, green, blue (RGB) imaging is a promising tool for satisfying these demands for practical application. Imaging with broadband fi lters, as in the case of digital RGB imaging, can also probe spectral information without mechanical rotation of a filter wheel. We have developed an simple imaging technique with a digital RGB camera for in vivo functional imaging of biological tissues. Th e experimental results indicated the ability to evaluate the physiological reactions and hemodynamics in rats and humans.
Yongsoo Lee
Oh and Lee Medical Robot, Inc, South Korea
Title: Robotic Irradiation of Medical Lasers
Time : 09:20-09:45
Biography:
Yongsoo Lee has completed his Medical degree at Yonsei University, South Korea. He is the Co-founder and Co-CEO of Oh and Lee Medical Robot, Inc. and affi liated to Yonsei YL Laser Dermatology and Plastic Surgery in South Korea. He has published many papers in respected journals and has served as an Editorial Board Member of medical journals. He also served as the sole Editor of “Scars and Scarring: Causes, Types and Treatment Options,” published by Nova Biomedical, New York, USA.
Abstract:
Studies on laser emission made the application to human skin possible. However, even though the signifi cance of irradiation has been recognized through adverse eff ects, such as post-laser burns and spotty hypopigmentation, few studies have been performed on laser irradiation. Excessive overlap of laser beams over a short period of time causes burns, while excessive overlap over a long period of time (days) results in spotty hypopigmentation, even with carefully-set emission parameters. Th is small fraction of adverse eff ects may be preventable through the use of robotic laser irradiation. Last April, in San Diego, CA, USA, a comparative study on manual and robotic irradiation was presented at the 37th Annual Conference of the American Society for Laser Medicine and Surgery. Th is study entitled as “Comparative Analysis of the Evenness of Laser Irradiation by a Robot vs. Human Hand: A Pilot Study of the Implication on the Eff ectiveness and Safety of Energy-Based Medical Devices”, demonstrated that robotic irradiation was more consistent and even compared with manual irradiation at frequencies of 10 Hz and 30 Hz. Moreover, the inconsistency of manual irradiation at frequencies of 10-30 Hz was demonstrated, while the robot demonstrated no statistical inconsistency at 10-30 Hz. Truly even laser beam irradiation of three-dimensional surfaces, such as the human face requires a high degree of precision and consistency, as the curvature varies from one point to another. Studies on laser irradiation have been nearly impossible, because of the inaccuracy and inconsistency of the human hand. As inconsistency and imprecision can be overcome with robotic irradiation, new study subjects have arisen for investigation of the eff ects of irradiation patterns on clinical outcomes. Robotic irradiation would enable us to achieve quicker and better outcomes, as well as to prevent the adverse eff ects described above.
Masahiro Motosuke
Tokyo University of Science, Japan
Title: Simple way of optical manipulation of particles/cells in microfluidic systems
Time : 09:45-10:10
Biography:
Masahiro Motosuke obtained his PhD in 2006 from Keio University. He joined the Department of Mechanical Engineering at Tokyo University of Science, and then was in Department of Micro/Nanotechnology at Technical University of Denmark. He is currently an Associate Professor of Tokyo University of Science from 2012. His research interest is on the development of biomedical optical sensing and control technology in advanced lab-on-a-chip platform, including external-fi eld-induced liquid/particle/cell handling.
Abstract:
Optical manipulation of small objects, e.g., particle and cells, has been widely exploited as a fundamental research tool in biochemical analysis for molecules or cell screening. However, utilization of optical force relying on controlling radiation pressure to the targets basically needs fi ne adjustment of optics so that this technology has not been used in Point-of-Care (POC) diagnostics including advanced Lab-on-a-chip (LOAC) platform that is drastically developing fi elds with the aid of micro/nanofabrication. In out study, possibility of optical manipulation for particles or calls in microfl uidic systems without any optical elements was investigated. Firstly, the use of scattering force was considered. Th is allows us to use low-evergy-density light for manipulation. Th en we exploited microfabricated integrated optics which gently focused iraddiated light to targets in microchannel to promote mobility of the targets. Our approach can expand the use of optical force in simpler way toward highly functionalized POC diagnostics based on LOAC platform.
Albrecht Lindinger
Freie Universität Berlin, Germany
Title: Fluorescence anisotropy excitation by polarization-shaped laser pulses after transmission through a kagome fiber
Time : 10:10-10:35
Biography:
Albrecht Lindinger has earned his PhD on helium droplet spectroscopy in Göttingen in the group of J-P Toennies and completed his Post-doc term in Berkeley in the group of D Neumark. He received his habilitation in the fi eld of coherent control at the Freie Universität Berlin in the group of L Wöste and is now working as a Lecturer in the Institute of Experimental Physics at the Freie Universität Berlin. He has published 80 peer-reviewed papers in reputed journals. His main scientifi c interests are laser optics, coherent control, and biophotonics
Abstract:
Laser pulse shaping for control of photo-induced molecular processes has attained considerable success in recent years. It became most exciting when pulse shaper set-ups were employed to generate tailored pulses, which optimally drive the induced processes. Lately, polarization pulse shaping was explored to examine the vectorial character of the light fi eld. Novel pulse shaping schemes for simultaneous phase, amplitude and polarization control were designed and a parametric subpulse encoding was developed. Th ereby, the physically intuitive parameters like chirps and polarization states of subpulses can be controlled. Th is yields new perspectives of utilizing all properties of the light fi eld in the pulse modulation. Currently, pulse shaping methods are increasingly used to investigate biologically relevant systems. Th ereto, pulse shaping is applied to multi-photon excitated fl uorescence, which enables to exploit intrapulse interference eff ects. In this contribution improved fl uorescence contrast between dyes is reported by two-photon excitation with polarization shaped laser pulses behind a kagome fi ber utilizing the anisotropy of the dye molecules. Particularly phase and polarization tailored pulses were employed for two-photon excited fl uorescence of dyes in liquid behind the kagome fi ber. The distortions due to the optical fi ber properties were precompensated to receive predefi ned polarization shaped pulses at the distal end of the kagome fi ber. Th is enabled to optimally excite one dye in one polarization direction and simultaneously the other dye in the other polarization direction. Th e presented method has a high potential for endoscopic applications due to the unique properties of kagome fi bers for guiding ultrashort laser pulses.
Victor Kärcher
University of Münster, Germany
Title: Wavefront propagation simulations for a hard x-ray split-and-delay unit at the European XFEL
Time : 10:50-11:15
Biography:
Victor Kärcher has completed his Bachelor’s in Physics from the University of Münster, Germany. He works on the simulation of x-ray optics in the Group of Helmut Zacharias at the University of Münster.
Abstract:
For the High Energy Density Instrument (HED) at the European XFEL a hard x-ray split-and-delay unit (SDU) is built covering photon energies in the range between 5 keV and 24 keV. Th is SDU enables time-resolved x-ray pump / x-ray probe experiments as well as sequential diff ractive imaging on a femtosecond to picosecond time scale. Th e set-up is based on wavefront splitting that has successfully been implemented at an autocorrelator at FLASH. Th e x-ray FEL pulses will be split by a sharp edge of a silicon mirror
coated with Mo/B4C and W/B4C multilayers. Both partial beams then pass variable delay lines. For diff erent wavelengths the angle of incidence onto the multilayer mirrors is adjusted in order to match the Bragg condition. Hence, maximum delays between +/- 1 ps at 24 keV and up to +/- 23 ps at 5 keV will be possible. In order to evaluate the infl uence of the device on experiments with focused hard x-ray pulses, time-dependent wave-optics simulations have been performed by means of Synchrotron Radiation Workshop (SRW) soft ware for SASE pulses at hv = 5 keV. Th is soft ware tool has recently been applied to assess the capability of the SDU to measure the temporal coherence properties of hard xray FEL-pulses. For this earlier study, diff raction at the beam splitter and a onedimensional cut through the surface profi le was taken into account. At the HED instrument, the XFEL radiation will be focused by means of compound refractive lenses (CRL) in order to perform experiments with intense, focused hard x-ray pulses. Th e results of these experiments severely depend on the fl uence and the spatial shape of the beam that is obtained in the focal area. Th erefore, in this paper the impact of wave-front distortions on the spatial intensity profi le in the focus is analyzed. For this purpose, the entire optical layout of the SDU, including diff raction on the beam splitter edge and the two-dimensional surface profi les of all eight mirrors are taken into account. Th e XFEL radiation is simulated using the output of the time-dependent SASE code FAST. For the simulations diff raction on the beam splitter edge as well as height and slope errors of all eight mirror surfaces are taken into account. Th e impact of these eff ects on the ability to focus the beam by means of compound refractive lenses (CRL) are analyzed.
Priyalal Stephen Wijewarnasuriya
US Army Research Laboratory, USA
Title: Development of high-operating long wave HGCDTE devices at army research laboratory
Time : 11:15-11:40
Biography:
Priyalal Stephen Wijewarnasuriya received his Ph.D. in Physics from the University of Illinois at Chicago. He was a member of technical Staff at the Rockwell Scientifi Center, CA and was dedicated to demonstration of novel, large-format infrared focal plane arrays for tactical and strategic military applications as well as for astronomy using HgCdTe alloy. He is currently leading the development of the next generation of infrared materials and devices at the U.S. Army Research Laboratory (ARL), Adelphi, MD. He is the Team Leader of "II-VI Materials and Devices Team". Dr. Wijewarnasuriya has authored or co-authored over 100 papers in the open technical literature, four book chapters and has presented his work at numerous national and international conferences. Currently, Dr. Wijewarnasuriya serves as a member of the organizing Committee for two international conferences in the infrared technology area.
Abstract:
Mercury cadmium telluride (HgCdTe) alloy is of great importance in sensing radiation from the near infrared (ï¬c ~ 1 μm) to the very long wavelength infrared (ï¬c ~ 15 μm). Much of the HgCdTe-related research and development work is carried out for cooled operation. Intrinsic carriers play a dominant role, especially at long-wavelength (LW 8 μm to 12 μm cut-off ) material near ambient temperatures due to high thermal generation of carriers. Th is results in low minority carrier lifetimes due to Auger recombination processes. Consequently, this low lifetime at high temperatures results in high dark currents and high noise. Cooling is one means of reducing this type of detector noise. Th e challenge is to design photon detectors to achieve background-limited performance (BLIP) at the highest possible operating temperature, with the greatest desire being operation close to ambient temperature. This paper present a path to achieve BLIP LW HgCdTe at twice the operating temperature of current 80K LW HgCdTe technology. High operating temperature LW devices would result in several advantages to an infrared imaging system. Th is technology will off er half the cool down time than the present technology for greater battle fi eld survivability with faster fi rst “image out” and less than half the power consumption (2 Watts vs 5 Watts). Th is will lead to dramatic reduction in size, weight and power resulting reduced cost (SWaP-C).
- YRF Session
Chair
Masashi Yamaguchi
Rensselaer Polytechnic Institute, USA
Co-Chair
Bellet Daniel
University of Grenoble, France
Session Introduction
Morad Khosravi Eghbal
University of Texas at San Antonio, USA
Title: W-band signal propagation in a WDM-over-OCDMA system
Time : 11:40-11:55
Biography:
Morad Khosravi Eghbal is currently a Graduate Research Assistant and a PhD Candidate at the Photonics Research Lab at the University of Texas at San Antonio. His research focus is on the millimeter wave radio-over-fi ber communication, optical coding and multi-wavelength transmission methods for 5G architecture.
Abstract:
In the past few years, because of the introduction of new bandwidth-demanding services and applications through mobile phone communication, demands for a higher capacity that can support execution of such services has increased substantially. An eff ective method to increase the capacity is to move to the higher working frequency bands (to the millimeter wave region (>30 GHz)). Th is region has an inherently higher capacity, plus is more secure and less occupied. However, millimeter waves when transmitted over the air are prone to atmospheric losses and are severely attenuated at a relatively short propagation distances. Th us, transmission of such signals through an optical fi ber link will simultaneously preserve the security, augmented capacity and yet the propagation distance without the signals being distorted and with relatively much longer than over-the air propagation. To add to the capacity even further, two of the well-established methods of increasing the capacity were merged in this work. First, was to increase an optical network’s capacity by employing several wavelength channels to transmit optical signals in parallel. Depending on the number of wavelength channels, the capacity of the system will be multiplied. Th e other was optical encoding that can help to further increase the capacity of the system and accommodate more channels to be transmitted simultaneously. Th is method assigns diff erent optical codes to each channel that is identical and can only be decoded individually. The is work, utilizes above methods to increase the capacity of a W-band radio-over-fi ber WDM-over- OCDMA system to accommodate more users per channel.
Ousmane I Barry
Nagoya University, Japan
Title: Growth and characterization of homoepitaxial m-plane GaN on native bulk GaN substrates: Prospects of next-generation electronic devices
Time : 11:55-12:10
Biography:
Ousmane I Barry is pursuing his fi nal year PhD at Nagoya University (NU) in Japan. He is also a Research Assistant at NU’s Institute of Materials and Systems for Sustainability (IMaSS). His research interests lie in the epitaxial growth and characterization of III-nitride compound semiconductor materials for optoelectronic and high-power device applications.
Abstract:
Nonpolar (m–plane) nitride heterostructures-based electronic devices are, unlike their polar (c-plane) counterparts, devoid of spontaneous polarization and piezoelectric fi elds. Th is unique feature makes nonpolar nitride materials very promising candidates for normally-off enhancement mode transistors which are highly demanded in safe power switching operation and also for very stable light emitters owing to the suppression of the quantum confi ned Stark eff ect. Recent breakthroughs in the bulk GaN growth technology have made low defect m–plane GaN substrates commercially available, paving the way for higher-quality homoepitaxial GaN growth and the development of vertical devices. However, the growth of nominally on-axis homoepitaxial GaN layers by metal-organic vapor phase epitaxy (MOVPE) on these native substrates generates wavy surface reliefs characterized by three-dimensional four-sided pyramidal hillocks which are detrimental for device fabrication. In addition, a higher unintentional impurity incorporation in non-polar nitride fi lms hinders device performance and reliability. In this talk, we present a technique to reduce the formation of pyramidal hillocks on the homoepitaxial m-GaN fi lms. Smooth surfaces with very low density of hillocks are achieved under high V/III ratio and exclusively N2 carrier gas. Th e electrical properties of m-GaN fi lms were found to be dependent on the surface morphology. A clear improvement of the electrical properties can be observed by suppressing the hillocks. Subsequently, impurities concentrations in m-GaN fi lms were signifi cantly reduced with V/III optimization and pure N2 carrier gas as confi rmed by SIMS analysis. Th ese results show good prospects for the development of next-generation electronic devices on non-polar GaN materials.
Mohammad A Z Al-Khateeb
Aston University, England
Title: Nonlinearity compensation using optical phase conjugation in optical fiber transmission systems
Time : 12:10-12:25
Biography:
Mohammad A Z Al-Khateeb has received his BSc in Communication and Software Engineering from Balqa’ Applied University, Jordan. Then he received his MSc degrees in Photonics Networks Engineering, Erasmus Mundus double Master’s degree, from Scuola Superiore Sant'Anna and Aston University. He is currently working towards PhD degree from Aston University under the supervision of Prof. Andrew Ellis. He is currently working across multiple projects, participated in organizing outreach activities such as LightFest (an International Year of Light event in Birmingham) and he is working on industrial contracts. He has authored/ co-authored over 12 publications and he is leading the development of theoretical tools and experimental demonstrations to exhibit the benefi ts of Optical Phase Conjugation in optical communication systems.
Abstract:
The fundamental performance limits of coherent optical transmission systems can be observed by a simple optimization between the linear noise and the nonlinear noise generated within the system. Optical Phase Conjugation (OPC) is considered to be one of the promising techniques to compensate for optical fi ber’s dispersion and nonlinearity that cause crosstalk between signals traveling through long-haul optical transmission systems, nonlinearity compensation can lead to signifi cant information capacity and distance reach expansion of optical fi ber transmission links. To get the full benefit from the deployment of OPC in optical transmission systems, a few considerations must be taken into account, such as: power profi le symmetry, fi ber’s dispersion slope and Polarization Mode Dispersion (PMD). In this contribution, we will present our simplifi ed theoretical predictions of optical fi ber transmission systems performance that deploy mid-link OPC and multi- OPC and we will show that the introduction of multi-OPC in an optical transmission system will minimize the impact of uncompensated/nondeterministic signal-signal nonlinear interactions due to fi ber’s PMD and signal-noise interactions. We will show wide range of simulation and experimental results that validate the theoretical predictions of system’s performance for various types of links: dispersion managed, dispersion unmanaged, discretely amplifi ed systems and distributed Raman amplifi ed systems. Also, we will present an extensive experimental study shows that the deployment of mid-link OPC can provide a signifi cant reach improvement in asymmetric lumped optical fi ber links when optimizing the span length.
Simeon Bogdanov
Purdue University, USA
Title: Quantum plasmonics with nitrogen-vacancy centers in diamond
Time : 12:25-12:40
Biography:
Simeon Bogdanv has received his PhD from the group of Manijeh Razeghi at Northwestern University in 2014. He is currently a Post-doctoral Research Associate at Purdue University in the group of Vladimir M Shalaev. His research interests include optoelectronic devices and quantum nanophotonics. His scientific achievements include the fabrication of InAs/GaSb superlattice photodetectors operating at 10 μm with the lowest dark current and the world’s brightest singlephoton source based on a nitrogen-vacancy center in diamond. He is Member of the Optical Society of America and serves as Reviewer for journals such as Optics Express, Optics Materials Express, Optics Letters and Nanophotonics.
Abstract:
Integrated quantum photonics imposes very stringent and oft en contradictory requirements on the design of integrated optical components. Plasmonic materials promise to confer novel properties to integrated quantum devices, that are not achievable with dielectric materials, such as nanoscale footprint, ultrafast operation and very strong light-matter interaction. In this talk, we will focus on the advantages of plasmonics for producing single photons. Our single-photon source is based on a nitrogen-vacancy center in diamond in a gap-plasmon cavity. It features a 200-fold speed-up in emission and a 30-fold increase in detected photon count compared to a reference source made without the plasmonic cavity. We discuss the potential of this enhancement mechanism for the engineering of tomorrow’s quantum photonic systems.
Johannes Hepp
Bavarian Center for Applied Energy Research, Germany
Title: Automatized optical quality assessment of photovoltaic modules
Time : 12:40-12:55
Biography:
Johannes Hepp has completed his MSc in Material Science from Friedrich-Alexander-University Erlangen-Nuremberg (FAU) and started working on his PhD as Reseacher at Bavarian Center for Applied Energy Research (ZAE Bayern) in February 2015. He is a Doctoral Researcher at the School of Advanced Optical
Technologies Erlangen (SAOT) and has authored/coauthored three publications.
Abstract:
Optical measurement techniques open the door to a wide variety of quality inspection tools. However, the number of customizable settings, like e.g. excitation sources or optical fi lters, is immense. For the quality inspection of thin film photovoltaics, we developed a Matlab based analysis tool in order to investigate as many parameters-potentially obtained by diff erent metrology methods-as possible, in a fast and reproducible way. Th is tool automatically executes procedures like peak wavelength detection of luminescence spectra (an indicator for material composition), hot spot detection in IR images (an indicator for recombination losses) and many mathematical combinations of multiple images taken under varying conditions. One application of this approach was to separate the eff ects of material composition from the infl uence of the defects on the performance of a photovoltaic module. Th e combination of these two performance indicators showed a good correlation to
the open circuit voltage of the device, proving the relevance of this analysis approach. Furthermore, the tool was capable of capturing further refi nements following from hardware improvements like the combination of images taken with special IR fi lters. Th is allowed us to combine the benefi ts of spectral and spatial resolution, which could be used in order to selectively identify certain chemical substances and their distribution in the sample of interest. Th e soft ware applies the scripted processing tasks successively on all samples of a measurement series within minutes, thus enabling high throughput inline measurements. Th e implemented graphical user interface (GUI) allows for a fl exible and user defi nable handling.
Farzad Rezaei
North Carolina State University, USA
Title: Surface modification of PET film via a large area atmospheric pressure plasma: An optical analysis of the plasma and surface characterization of the polymer film
Time : 13:45-14:00
Biography:
Farzad Rezaei has graduated with a PhD in Fiber and Polymer Science from the College of Textiles at North Carolina State University. Currently, he works at the College of Textiles as a Post-doctoral Research Scholar. The focus of his research is on polymeric coatings, surface modifi cation and plasma science.
Abstract:
This research presents a comprehensive study of surface modifi cation of polyethylene terephthalate fi lm substrates to improve its adhesion properties using a large area atmospheric plasma. Diff erent aspects of this study includes: analysis of the physical and chemical characteristics of the plasma as well as the substrates and evaluation of adhesion of an acrylate based hard coating onto PET substrates. PET is chemically inert to most coatings, but atmospheric plasmas can modify the surface in a manner that is compatible with high throughput manufacturing. First, optical emission spectroscopy was employed to analyze the plasma in terms of its chemical composition as well as physical characteristics such as electron temperature and density. Th is section estimates electron temperature of 0.2-0.4 eV and density in the order of 1014-1015 cm-3 for the studied plasmas. Second, various plasma gas mixtures with helium as the seed gas mixed with fraction of oxygen and/or nitrogen (0.5-1.1 v%) were used to carry out the surface treatment of the substrates at diff erent exposure doses between 15 to 75 J cm-2. Post-treatment characterization by XPS, AFM and a goniometer show that the surface becomes enriched with oxygen, rougher and more wetting depends on the power and composition of the plasma. Lastly, standard adhesion 180° T-peel tests indicated improved adhesion aft er treatment.
Marek Vostřák
University of West Bohemia, Czech Republic
Title: Diagnostics of laser remelting of thermally sprayed coatings using an infrared camera
Time : 14:00-14:15
Biography:
Marek VostÅ™ák is a PhD candidate in the fi eld of Laser Technologies. In 2010, he has received his Master’s degree in Applied Physics from the University of West Bohemia and he has been a Researcher in the New Technologies Research Centre since then. His research is focused on laser cladding and laser remelting and utilization of thermography measurement in these technologies. He is an author and co-author of numerous outcomes of applied research and some notable publications in this area, the most recent one is “Diagnostic of laser remelting of high velocity oxygen fuel sprayed stellite coatings using an infrared camera
published in Surface and Coatings Technology volume 318 (2017): 360–364.
Abstract:
Laser remelting of thermally sprayed coatings is a promising possibility how to improve their functional properties such as wear and corrosion resistance. To achieve the optimal results and the desired depth of remelting, it requires a precise control of laser process parameters. However, any suitable control of laser remelting process by means of infrared measurement was yet not described. In this study, a high-power diode laser was used to remelt the HVOF sprayed stellite coatings. Samples with a diff erent coating/substrate thickness ratio were utilized and by variating the process speed the diff erent depth of remelting was achieved. The remelting process was recorded by the combination of a Long Wavelength Infrared (LWIR) and a Near Infrared (NIR) camera. Th e experiment was designed to fi nd the most suitable method for diagnostics of a remelting process. The possibilities of evaluation of a temperature fi eld in the interaction zone are presented. Th e width of melting pool is calculated from the evaluated temperatures and then correlated with the measured depth of remelting. Th e approximations of their mutual dependence show very high correspondence. It indicates that this measurement can be used for controlling of the depth of remelting, regardless of the samples dimensions.
Maybritt Kuehn
Technische Universitaet Darmstadt, Germany
Title: Band alignment in organic light emitting diodes – on the track of thickness dependent onset voltage shifts
Time : 14:15-14:30
Biography:
Maybritt Kuehn has studied Material Science at the Technische Universitaet Darmstadt, Germany. With her diploma thesis she started to work in Jaegermann’s group, completed her PhD there and continued with Post-doctoral studies. She did her PhD thesis in cooperation with the Merck KGaA, Darmstadt, Germany, at Innovationlab Heidelberg, Germany and focused on pholelectron spectroscopy. In her PhD thesis, she investigated the infl uence of energetic alignment at organic/ organic-interfaces on the current-voltage behaviour of OLEDs.
Abstract:
Organic light emitting diodes play an important role in our daily life, e.g. as displays in smart phones. Nevertheless these modern multilayer devices oft en show unexpected eff ects during operation. One of these phenomena - the thickness dependent onset voltage shift - is topic of this contribution. Th e investigations concentrate on two OLEDs that only differ in the emission layer but show an entirely diff erent current-voltage behaviour. If the emission layer consists of the triplet host TH-A a shift in onset voltage in case of emission layer thickness variation can be observed. Using TH-B in the emission layer, an isomer to TH-A, the onset voltage remains unchanged. In a previous publication, we could show that an electric interface fi eld is responsible for the thickness dependent onset voltage shift . Th e interface fi eld is already present in the currentless case. Th is presentation now deals with the origin of such an interface fi eld. Th erefore the energetic alignment at the internal interfaces in the two diff erent devices is measured by performing in-situ step by step interface experiments using photoelectron spectroscopy. In case of the device showing no onset voltage shift a fl at band situation is measured, while in case of the other device (where there is the onset voltage shift ) the formation of space charge regions is detected. A further stack modifi cation proofs that the band bending at the hole injecting interface into the emission layer is responsible for the onset voltage shift .
Hongyang Wang
Dalian University of Technology, China
Title: The welding modes in Laser-arc hybrid lap welding of dissimilar metals
Time : 14:30-14:45
Biography:
Hongyang Wang received his PhD in Materials Manufacture Major from Dalian University of Technology, China. Now, he is working as an Associate Professor of
Dalian University of Technology, a Deputy Director of Key Laboratory of Liaoning Province in China. He is mainly committed to lights welding and dissimilar welding process. His research has brought him more than 20 papers in reputed journals with more than 200 of SCI citation.
Abstract:
The pluse laser-tungsten inert gas hybrid welding method was adopted to realize the welding dissimilar alloys process. The welding modes in the laser-arc hybrid welding lap joint were changed with the varying of laser and arc parameters, which made obviously eff ects on the dissimilar joints. In Ti and steel dissimilar welding lap joint with Cu interlayer, the welding mode in both of Ti and steel fusion zone were in conductive mode and the thickness of the intermetallic was limited by the accurate control of the welding heat. In Mg and Al alloys dissimilar welding lap joint with Ni interlayer, the welding mode in Mg fusion zone was in keyhole mode and Al fusion zone in conductive mode and the intermetallics was inhibited by the welding mode and interlayer. In Al and steel dissimilar welding lap joint with Cu interlayer, the welding modes in both of Al and steel fusion zone were in keyhole mode, but the thickness of the Al-Fe intermetallic was less than 10μm, which was reduced by the hybrid eff ect of the Cu interlayer and the welding sources. Th e welding mode should be changed by the character of the dissimilar metals. Th e formation and distribution of the intermetallic was decided by the welding sources, base metal and the welding process, which made obvious eff ect on the property of the joint.
Najmeh Abbasirad
Friedrich Schiller University Jena, Germany
Title: Mapping surface plasmon polaritons by near-infrared dual-probe scanning near field optical microscope
Time : 14:45-15:00
Biography:
Najmeh Abbasirad is currently pursuing her PhD in Nano-optics group at the Institute of Applied Physics, Friedrich Schiller University Jena under supervision of Prof. Thomas Pertsch. At present her research focuses on near-fi eld optical microscopy and developing dual-probe SNOM for characterization of optical nanostructures
Abstract:
Scanning near-fi eld optical microscopy (SNOM) is a powerful technique to visualize optical phenomena within the nearfield region of optical nanostructure. In standard aperture SNOM measurements, there is a small aperture which serves as a point-like emitter or detector of light. In dual-probe SNOM, there are two aperture tips which simultaneously illuminate and collect the light on a surface of nanostructures. In the dual-probe confi guration, both illumination and collection resolution depends on the aperture size and can overcome the diff raction limit. Furthermore, the measurement signal is not infl uenced by background radiation stemming from an illumination laser spot. Although the dual-probe SNOM measurements have been reported for the measurement of surface plasmon polaritons (SPPs) propagation as well as local carrier dynamics in quantum wells, due to complications of dual-probe SNOM measurements, this technique is not yet a common near-field characterization method. Recently, we have introduced a fully automated and robust dual-probe SNOM technique which has facilitated the robust implementation of the measurement. In this technique, a reliable collision avoidance scheme only based on shear force interaction between two tips is employed. Th e fully automated dual-probe technique not only simplifies the application of dual-probe SNOM, but a low noise electronic also leads to considerably improved data acquisition. In this work, we demonstrate the capability and stability of the method by measuring SPPs propagation for near-infrared excitation. Th e illumination probe excited SPPs on a gold fi lm at 1550 nm wavelength. Th e SPP propagation is mapped on an area around the illumination probe by raster scanning of the collection probe. A computer-controlled collision avoidance scheme prevents the collision of two probes. Th erefore, the optical signal is mapped without user interference. Th e fully automated dual-probe SNOM could open up a new possibility to quantitatively investigate and image the optical fi eld interaction with plasmonic and dielectric devices as well as surface wave propagation.
Zanozina Ekaterina
J Heyrovsky Institute of Physical Chemistry, Czech Republic
Title: FTIR laboratory measurement of O I spectra in 0.77–12.5 μm spectral range
Time : 15:00-15:15
Biography:
Zanozina Ekaterina has completed her PhD from Voronezh University and State Research Center of Russian Federation Troitsk Institute For Innovation and Fusion Research. She is now a Post-doctoral Researcher in J Heyrovsky Institute of Physical Chemistry AV ÄŒR in Prague. In the Department of Spectroscopy, she actively participates in solving problems, which mainly include the identifi cation of infrared spectra of atoms and complex analysis of spectral data. She is the author of 11 publications in impacted journals with 37 citations. She presented her results at six international conferences focusing mainly on spectroscopic issues. Her research interests include Rydberg states of atoms and molecules; interaction of electromagnetic radiation with atoms; mathematical and computational physics; time-resolved FTIR spectroscopy and transition probabilities.
Abstract:
Compared with the visible and ultraviolet ranges, fewer atomic and ionic lines are available in the infrared spectral region. Atlases of stellar spectra oft en provide only a short list of identifi ed lines and modern laboratory-based spectral features for wavelengths longer than 1 micron are not available for most elements. In spite of the fact that oxygen is one of the most abundant elements in the universe, very few studies of their spectra in infrared region have been reported. Th e normal system of O I terms available in the NIST atomic spectra database was established more than a half-century ago. Th e present work attempts to address the above issues. We exploited the great advantages of time-resolved Fourier transform spectroscopy, such as its constant high resolution and energy throughput, to record high-resolution spectra of oxygen in a wide domain of 800-13000 cm-1 (0.77-12.5 μm). With the help of recent high-accuracy direct measurements of the 3p level in the UV, we performed a re-optimization of O I level energies. Th is re-optimization uses 146 O I lines in the infrared (including 59 lines not measured previously in the laboratory) to yield more accurate energies of levels with n=4-7, l≤6. For some of these levels, we experimentally found fi ne structure splitting for the fi rst time. Th e line classifi cation was performed using relative line strengths expressed in terms of transition dipole matrix elements calculated with the help of quantum defect theory (QDT). To verify our QDT calculations of dipole transition matrix elements, we checked several QDT-calculated oscillator which
strengthened against the results of other authors. Th e method showed the good agreement with the vast majority of the data listed in the NIST ASD.
Iman Sabri Alirezaei
Otto-von-Guericke University of Magdeburg, Germany
Title: On-chip integrated a 3D-CMOS Si photodetector array with a fiber couplers platform for remote optical fiber monitoring
Time : 15:15-15:30
Biography:
Iman Sabri Alirezaei received his MSc degree in Applied Physics from Shahid Beheshti University (SBU). He is currently doing his PhD and working as a Research Assistant in Electrical Engineering at Institute of Micro and Sensor Systems, Magdeburg University. His current research interests include CMOS-MEMS devices, micro- and nano-photonic devices, optical fi ber sensors, integrated photodetectors and Lab-on-a-chip.
Abstract:
A silicon-based photodetector array with on-chip integration to tiny fiber strands on a single chip is fabricated using 3D-complementary metal-oxide-semiconductor (CMOS) and microelectromechanical systems (MEMS) technology. The 3D-detector involves a vertical photoactive area as large as the fi ber diameter for direct butt-coupling to the optical fiber. Novel ultra-deep trench isolation with a passivation method is carried out to overcome the leakage current as well as the surface recombination current and the dark current, which arise from the fabrication of the ultra-deep trenches. The passivation method consisting of SU-8 polymer enables to implement the deep trenches with a depth of 30μm for both the vertical photoactive area and the inter-pixel trench isolation in the CMOS process. All pixels in the linear array are held at the same applied reverse voltage, by stacking the interconnection line across the pixels. Besides, a tapered U-groove array is built on the monolithically integrated fi ber couplers platform for chip-level fi ber insertion. Th is detector shows an external quantum efficiency of 63.82%, corresponding to the photoresponsivity of 0.32A/W, at a wavelength of 631nm for 2V reverse bias. The proposed detector array integrated into a fiber bundle is very promising to apply for remote optical fiber sensing applications in harsh environments, where involve high electromagnetic fields or RF signals such as magnetic resonance imaging (MRI) or positron emission tomography (PET).
Nadiah Aldaleeli
Swansea University, UK
Title: Intracellular pH detection of Brachionus plicatilis with pMBA pH nanosensor
Time : 15:30-15:45
Biography:
Nadiah Aldaleeli received her BE degree in Physics from the King Faisal University, Saudi Arabia, in 2003 and the Master’s degree in Laser and Spectra from King Saud University in 2008 and her Master's project ( Spectral diagnosis of cancer samples before and after surgery) was awarded the golden medal for the best research in that year. In 2010, she joined the Department of Physics, Aljouf University, Saudi Arabia, as a Lecturer and since 2013, have been with the Department of Physics, Education Collage, Imam Abdulrahman Bin Faisal University, Saudi Arabia, as a Lecturer as well. She is currently at Swansea University for a PhD
program in the fi eld of Nanotechnology and her research interests lie in laser diagnostics and spectroscopy.
Abstract:
An important application of Surface Enhanced Raman Scattering (SERS) is the potential of intracellular analysis based on Raman reporters attached to nanoprobes. SERS is an appropriate technique for identifi cation of molecular species of a biological system; measuring local chemical changes at the subcellular level with high spatial and temporal resolution. Measuring pH utilising the enhanced Raman response from pMBA when it has functionalised gold nanoparticles (Au NPs) has attracted signifi cant attentions. Th us, the application of such a system to the measurement of intracellular pH is a key aspect of current development. Th e importance of monitoring the intracellular pH appears in gaining a better understanding of the occurrence and progression of diseases. Herein, the sensitivity of pH nanoprobe based on pMBA functionalised 30 nm Au NPs to the pH changes of the surrounding solutions has been investigated not only with a pure stock solution of pMBA-Au but also when internalised inside Brachionus plicatilis. The preliminary results show that the chemical sensing of the nanoscales probe is maintained when inserted into living cells giving an evidence of the ability of such probe to monitor intracellular pH changes. The sensitivity of such nanoprobe to the pH changes inside the organism is refl ected in the changes of the SERS response of the pH calibration modes at 696 cm-1, 1393 cm-1 and 1702 cm-1 which shows a similar trend to the pure stock solution of pMBA-Au.
Junze Li
Microsystem and Terahertz Research Center, China
Title: The MOCVD overgrowth studies of III-Nitride on Bragg grating for distributed feedback lasers
Time : 15:45-16:00
Biography:
Junze Li has completed his PhD from Peking University. He is working as the Research Assistant of Microsystem & Terahertz Research Center of China Academy of Engineering Physics (CAEP). He has published more than 20 papers in reputed journals.
Abstract:
Gallium nitride lasers, especially the single-mode distributed feedback (DFB) lasers using Bragg gratings own potential applications in communication systems due to their high-speed modulation. For the blue-violet light, the value of a period of the first-order diff raction grating is about 80 nm. Th is poses a big challenge when forming the high precision grating and nitride overgrowth based on it. We fabricated the fi ne step shape structure of fi rst-order and 3rd order grating by nanoimprint and inductively coupled plasma (ICP) dry etching and we proceeded with an epitaxial regrowth of AlGaN layer with 6% to 12% Al content. Th en we designed a series of gratings with diff erent period, depths and duty ratios to study the influence of grating structure on nano-heteroepitaxy. And we improved the overgrowth by enhancing the growth temperature as high as 1450°C. Moreover, we observed the nucleation and growth process by step-by-step growth to study the growth mode for nitride overgrowth on grating, under the condition that the grating period was larger than the mental migration length on the surface. Th ese samples were analyzed structurally by high-resolution transmission electron microscopy (HRTEM) and spacespectrally by cathodoluminescence (CL). Th e growth dynamics analysis of the nitride nano-epitaxial in this research is one of the frontier areas of nitride photoelectric devices, which is not only meaningful in semiconductor material physics, but also important for related scientifi c researches and applications.
Ilkay Demir
Cumhuriyet University, Turkey
Title: High quality nitride materials (AlN and AlGaN) on Si and sapphire substrates and UV-LED applications
Time : 16:00-16:15
Biography:
Ilkay Demir has completed his PhD at the age of 32 years from Cumhuriyet University, Physics Department. He is the researcher of Nanophotonics Research and Application Center and Department of Nanotechnology Enginnering. He spent 1 year of his PhD at Center for Quantum Devices under supervision of Prof. Manijeh Razeghi. He has published 5 papers in reputed journals.
Abstract:
The growth of thick, high quality and low-stress AlN fi lms on Si and Al2O3 substrates is highly desired for a number of applications like the development of micro and nanoelectromechanical system (MEMS and NEMS) technologies and particularly for fabricating AlGaN based UV-LEDs. UV-LEDs are attractive as they are applied in many areas, such as air and water sterilization, efficient white lighting, high-density optical data storage and military applications such as biological agent detection and non-lineof-sight communication. However, the development of UV-LEDs on Si substrates is highly desired for a series of reasons like the availability of cheap, large-diameter silicon wafers, the much lower device processing costs, and the possibility of monolithical integration of the UV-LEDs with Si circuitry. In addition, effi cient AlGaN based deep UV-LEDs require layers and substrates which are transparent in UV light. So, it is preferable to grow the AlGaN based deep UV-LEDs active layers on Si substrates as the Si can be removed by chemical treatment to allow back illumination and avoid the generation and reabsorption of UV light by backside emission. Th ese advantages make silicon an attractive substrate for AlGaN based UV devices. Additionally high quality AlN template on Al2O3 substrate still is the key layer to grow high quality AlN and high Al content AlGaN materials for DUV applications since AlN substrate price and size are not suitable for mass production.