10^th International Conference and Exhibition on Lasers, Optics & Photonics November 26-28, 2018 - Los Angeles, California, USA

Biography:

Douglas R McCarter is the Technical Integrator of McCarter Machine and Technology Inc., founded in 1981. McCarter’s patented and proprietary silicon processes achievements were documented by published technical papers and over 50 oral presentations. In turn, he has won many awards, mentioned in Forbes.com, Kiplinger Letter, Entrepenuer.com, Nasa Tech Briefs, New Mexico Optics, Missile Defense Briefs Open and Classifi ed and recognized as the current world expert in precision silicon components. He has served as Member of Editorial Staff of Advanced Optical Technology, in Munich Germany since 2012. In 2016, Dr. Babin, USA Congressman District 37 and Leader of Nasa Funding, endorsed McCarter. In addition to over 3000 hours of Technical Schools, McCarter has been directly mentored for six years by the late Frank Anthony, Bell Labs Silicon Director and past 10 years Roger Paquin, Perk and Elmer retired Materials Expert. He is one of SPIE’s Inaugural 18 Senior Members, Editor Member on AOT, Advanced Optical Technology in Munich and Committee Member of OMICS Laser and Photonics.

Abstract:

Space Debris Mitigation is a unique problem requiring a unique solution. Space debris includes all types of potentially harmful objects, both seen and unseen, such as man-made idle satellites, abandoned tools, gas cylinders and satellite parts from ruptured and/or impacted satellites. Most alarming is the growing number of close calls with Cosmic-made asteroids and comets. Th e current materials used in Space Optics continually misses seeing asteroids and ground optics see most of them-After they have passed the earth. In addition, present day technology cannot deter any space debris that doesn’t burn up during atmospheric reentry, regardless of the source.

Large asteroids, called planetoids, are being seen and tracked, yet there is no proven option to deter from one or more causing global damage. Medium asteroids, called asteroids and small asteroids are called meteoroids, which can be city killers, are mostly never detected until they hit. Th is size asteroid has a signature that is too dim to detect or the surrounding planets are too bright and drown out any sign of the asteroid. Since the year 2000, over 28 Kiloton meteoroids, called meteorites after entering our atmosphere, have hit the earth. Th e near miss of the Russian city of Chelyabinsk in 2013 caused millions of dollars of damage and over 1200 physical injuries. Th is debris event caused mankind to begin asking” Why can we not see these objects and if we can see them, what can we do except evacuate?”

Th is class will show why asteroid detection is diffi cult and how to overcome these obstacles. Aft er two decades of prototyping and third- party testing, including MDA SBIR’s, McCarter has created a RL-6 silicon technology solution to build a Silicon Solar System, S3, that will perform both as a detector of space debris and as a direct deterrence of damage caused by this debris. This system will not only see dark cold objects but also ultimately control their fate.

Th e S3, will Seek-Track-Lase most space debris, operating as a squadron of individual satellites. Th e immediate mission will be to laser cut space trash, including dead satellites, to a safe size, then laser pulse it to slow and allow it to fall out of orbit. Lessons learned from clearing satellite orbits of trash will teach many valuable lessons such as proper positioning, power rate adjustments, responses of cut off pieces and guiding of trash to designated locations. To control micrometeorites, dust and/or paint fl ecks, it will be necessary to make a laser scanner screen. While taking out the trash doesn’t seem to be an attractive or rewarding eff ort, we will show that only aft er this proof of concept will we have the confi dence and experience needed to combat
the incoming asteroids referred to in McCarter’s SPIE paper as Space Invaders.

Biography:

Everardo Vargas Rodriguez completed an MSc in instrumentation at the Universidad de Guanajuato, Mexico. Afterward, he received a PhD in Optoelectronics at the University of Southampton in 2007. He joined the University of Guanajuato in Mexico since 2007 and later he was appointed as a Director of the Department for Multidisciplinary Studies were he served from 2008-2016. Currently, he is an Academic Editor of the Journal of Sensors and he is interested in optoelectronics sensors and fi ber lasers.

Abstract:

Gas sensors based on Tunable Laser Absorption Spectroscopy (TLAS) are widely used due to their high sensitivity and selectivity. Moreover, there currently exists a wide range of laser options to implement this application. Depending on the sensor system design some authors have been capable to enhance diff erent technical characteristics such as the minimum detectable concentration and the sensitivity over the certain dynamic range. In this work, a novel tailored algorithm to enhance the overall sensitivity of gas concentration sensors based on the Direct Absorption Tunable Laser Absorption Spectroscopy (DA-ATLAS) method is presented. By using this algorithm, the sensor sensitivity can be custom-designed to be quasi-constant over a much larger dynamic range compared with that obtained by typical methods based on a single statistics feature of the sensor signal output (peak amplitude, area under the curve, mean or Root-Mean-Square (RMS)). Moreover, based on the proposed algorithm, it is shown that it is possible to establish a quasi-linear relationship between a tailored statistics feature and the concentration within the wider dynamic range. Th is consequently allowed us to get a high and quasi-constant sensitivity within this concentration range. Furthermore, this algorithm can be applied to currently-designed sensors since it is only necessary to change the way in which the sensor signal output is processed. Th is new algorithm is based on the combination of diff erent statistical features of the sensor signal output instead to consider just one statistics feature (area, peak amplitude, RMS). Th is type of statistical analysis is commonly used in digital image processing for texture measurements. Finally, in order to support the general performance of the algorithm, a basic C2H2 sensor based on DA-ATLAS was implemented and its experimental measurements are in agreement with the simulated results provided by our algorithm.

Biography:

Takashi Matsui received BE, ME and PhD degrees in electronic engineering from Hokkaido University, Sapporo, Japan, in 2001, 2003 and 2008, respectively. He also attained the status of Professional Engineer (P.E.Jp) in electrical and electronic engineering in 2009. In 2003, he joined NTT Access Network Service Systems Laboratories, Ibaraki, Japan. He has been engaged in research on the design and measurement techniques of optical fi bers, in particular, has studied on the photonic crystal fi bers, bending-loss insensitive fi bers and the multi-core fi ber technology for telecommunication use and related fi ber design, measurement methods and applications of Brillouin scattering phenomena. He is a member of the Institute of Electronics, Information and Communication Engineers (IEICE) of Japan and an expert of technical committee 86 for international standards for fi ber optics technology in International Electrotechnical Commission (IEC).

Abstract:

Space division multiplexing (SDM) technology has been received increasing attention to increase transmission capacity extremely, which can overcome the capacity limit of the existing single-mode fi bers (SMFs). The SDM transmission can be realized by using a multi-core fi ber (MCF) or few-mode fi ber (FMF). In particular, the FMF can increase the number of spatial channels greatly by utilizing the mode division multiplexing (MDM) technology with the MIMO processing. Here, the MDM transmission raises some new issues which have not been considered in the SMF based transmission system. In particular, the diff erential modal delay (DMD) and the mode dependent loss (MDL) are unique of the FMF based transmission line. Th e larger DMD increases the complexity of the MIMO receiver. Th e MDL severely restricts the transmission speed and/or distance. Th erefore, it is important to specify these parameters of the FMF to construct the MDM transmission line. The DMD measurement method is well-established based on the time-of-fl ight method since it is also necessary to specify the bandwidth of existing multi-mode fi bers. Th e MDL is induced by some factors in the transmission line such as diff erential modal attenuation of fi bers, splices and devices and the mode conversion in the fi ber and at splices. Th erefore, it is important to specify the modal dependence of the loss factors for the FMF. Th e loss measurement of the FMF can be conducted with the conventional test procedure by utilizing the mode multiplexer which has suffi ciently high mode extinction ratio. However, the increase in the number of modes degrades the mode extinction ratio, which degrades the measurement accuracy. Recently, measurement methods of each mode in the FMF have been proposed by considering the mode power ratio, which is the variable mode power ratio method and the mode fi lter based OTDR method. Th ey can off er suffi ciently high accuracy of less than 0.005dB/km for two-mode fi bers. Th e splice loss is estimated by using the mode-fi eld diameter (MFD) for SMFs in general. We have investigated the applicability of the conventional near-fi eld pattern (NFP), far-fi eld pattern (FFP) and variable aperture (VA) methods to the higher-order modes in the FMFs. We found that the MFD values from the FFP and VA methods provided the splice loss value which well-agreed with the experimental results. Th erefore, it can be considered that the effective MFD value by utilizing these two methods is appropriate to consider the splice loss properties of the FMF. Th e loss and spice characteristics of the FMF directly eff ects on the transmission performance and it is essential to establish the specifi cations and their test procedures of the FMF for the interconnectivity and mass productivity. It can be considered that new approaches to control the characteristics of each mode are required to reduce the DMD and MDL for the FMF based transmission line.

Biography:

Weida Hu received his BS and MS degree in Material of Science from Wuhan University of Technology, Wuhan, China, in 2001 and 2004, respectively and PhD degree (with honors) in Microelectronics and Solid-State electronics from the Shanghai Institute of Technical Physics (SITP), Chinese Academy of Sciences (CAS), in 2007. He is currently a full professor on fabrication and characterization of infrared photodetectors in SITP. He has authored or coauthored more than 110 technical journal papers and conference presentations with the total citations of 3100 and h-index of 33. He received the National Science Fund for Distinguished Young Scholars in 2017, National Science Fund for Excellent Young Scholars in 2013 and National Program for Support of Top-notch Young Professionals (TenThousand Talents Program for Young Talents) in 2015. He is selected as the Royal Society-Newton Advanced Fellowship in 2017. He is also serving as the Associate Editor of Infrared Physics & Technology, the Executive Editor of Optical and Quantum Electronics, the Program Committee of SPIE DCS Defense and Security-Infrared Technology and Applications (USA) and the Program Committee of the International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD).

Abstract:

Bonded tightly in the plane and stacked with weak van der Waals force, two-dimensional (2D) materials have attracted increasing attention over the past decade owing to their unique structures and physical properties. To date, 2D materials comprise graphene, black phosphorus (BP), transition metal dichalcogenides (TMDs), boron nitride (BN) and so forth. Among them, graphene was fi rst discovered and studied as early as 2004. Because of the reduced feature dimensions, quantum confi nement eff ects in 2D systems are particularly signifi cant. With weaker dielectric screening in a several-nanometer or even atomic thickness, stronger Coulomb interactions occur. 2D systems provide an open platform for exploring novel physical phenomena and mechanisms. For instance, the breaking of inversion symmetry and strong valley-spin coupling in TMDs cause them to exhibit valley-dependent circular dichroism and scaling the material from multilayer to monolayer can realize an indirect-to-direct bandgap transition. Th erefore much eff ort has been devoted to seeking various applications based on 2D materials and the study of photodetectors based on 2D materials is a hot research fi eld. In this report, we introduce localized field enhanced 2D material photodetectors (2DPDs) from ultraviolet, visible to infrared in the sight of the infl uence of device structure on photodetector performance instead of directly illustrating the detection mechanisms. Six kinds of the localized field are summarized. Th ey are a ferroelectric fi eld, photogating electric fi eld, floating gate induced electrostatic fi eld, interlayer built-in fi eld, localized optical fi eld and photo-induced temperature gradient fi eld, respectively. By suppressing the background noise, enhancing the optical absorption, improving the electron-hole separation effi ciency, amplifying the photogain or extending the detection range, these localized fi elds are demonstrated to eff ectively promote the detection ability of 2DPDs. Particularly, among them, the photogating has been demonstrated to play a very important role especially in photodetectors based on hybrid structures. We consider photogating as a way of conductance modulation through photo-induced gate voltage instead of simply and totally attributing it to trap states. A high gain-bandwidth product as high as 109Hz has been achieved for photodetectors enhanced by the trap- and hybrid-induced photogating, though a trade-off has to be made between gain and bandwidth. We also put forward the general photogating according to another three reported studies very recently. General photogating may enable simultaneous high gain and high bandwidth, paving the way to explore novel high-performance photodetectors.

Biography:

Yanbo Bai has completed his PhD from Northwestern University. His research at Northwestern led to the most effi cient and most powerful quantum cascade lasers. His current role at Coherent is to develop more effi cient optically pumped semiconductor lasers and explore new wavelength capabilities. He has published more than 40 papers in reputed journals, such as Nature Photonics, Applied Physics Letters, Journal of Applied Physics, etc.

Abstract:

The bandwidth of an optically pumped semiconductor laser (OPS) is determined by the bandwidth of the material gain, the bandwidth of the longitudinal confi nement factor (LCF) and the bandwidth of the Distributed Bragg Refl ector (DBR). For a typical OPS-structure at 1064nm, the bandwidth of the DBR is the largest among them. In this work, we demonstrate a tunable OPS-structure with broadened material gain and LCF, so that the bandwidth of the OPS is close to the bandwidth of the DBR. Th e laser outputs more than 2W, tunable in a wavelength range of 1035–1100nm. High power and high bandwidth are difficult to achieve simultaneously in an OPS. For high power, one would prefer a high out-coupling (OC) for a high slope effi ciency. For high bandwidth, a low OC is necessary to extend the usable gain as far away from the center as possible. Nearly all widely tunable OPS result is demonstrated with an HR cavity (low OC), where the output power is only a fraction of the pump power. In this work, the OPS-structure is engineered in such a way that the modal gain (the product of the material gain and longitudinal confi nement factor) is as fl at as possible in the usable band of the DBR so that there is still substantial gain at the edges of the tuning range. Th is is the key feature to achieve simultaneously high power and broad tuning range.

Biography:

Yutaka Fukuchi was born in Tochigi, Japan, on April 29, 1975. He received the BS and MS degrees in electronics engineering from Tokyo University of Science, Chiba, Japan, in 1998 and 2000, respectively and the PhD degree in electronics engineering from the University of Tokyo, Tokyo, Japan, in 2003. In 2003, he joined the Department of Electrical Engineering, Faculty of Engineering, Tokyo University of Science, Tokyo, Japan as an Assistant Professor. From 2003 to 2005, he was also a Co-operative Research Fellow in Research Center for Advanced Science and Technology, the University of Tokyo, Tokyo, Japan. Then, he became a Junior Associate Professor of Tokyo University of Science in 2006. Since 2009, he has been an Associate Professor at this university. From 2013 to 2014, he was a Visiting Research Fellow with the High-Speed Optical Communications Group, Department of Photonics Engineering, Technical University of Denmark, Lyngby, Denmark. He has published over 120 papers in major international journals and conferences. His research interests are optical communications, quantum optics, nonlinear optics and their applications. He is a member of the Institute of Electrical and Electronics Engineers (IEEE), the Optical Society of America (OSA) and the Institute of Electronics, Information and Communication Engineers (IEICE).

Abstract:

All-optical and tunable wavelength converters (WCs) can off er many attractive functions such as optical channel routing, optical add-drop multiplexing, optical label processing and dynamic light-path establishment for constructing transparent and scalable wavelength-division multiplexed (WDM) networks or future optical packet switched systems. Th e potential of such WCs has already been revealed in a number of system experiments. To date, a selective and tunable WC (STWC) has been realized by employing the cascaded second-order nonlinear eff ect of sum frequency mixing (SFM) and diff erence frequency mixing (DFM) in a quasi-phase-matched (QPM) lithium niobate (LN) device. In this technique, a signal light and two pump lights 1 and 2, which have angular frequencies ωs, ωp1 and ωp2, respectively are launched on the device with a QPM frequency of ωQPM; to satisfy the QPM condition, ωp1 is set to 2ωQPM–ωs; SFM between the signal light and the pump light 1 then produces a sum-frequency component at 2ωQPM; a wavelength-converted output fi nally appears at 2ωQPM–ωp2 through DFM between the 2ωQPM component and the pump light 2. Generally, the wavelength conversion effi ciency of the QPM-LN devices or the output power of the wavelength-converted signal light increases dramatically as the length of the LN crystal becomes longer. In such a dual-pumped wavelength conversion scheme, however, the available signal bandwidth is strictly limited by the QPM bandwidth of the device. In other words, the crystal length of the QPM-LN device has to be optimally determined so that the QPM bandwidth corresponds to or is slightly broader than the bandwidth of the original signals to be wavelength-converted. In this paper, we review a technique of the QPM-LN-based STWC from an arbitrary wavelength to another arbitrary one. Through wavelength conversion experiments using short optical pulses for the QPM-LN devices having diff erent crystal length, we investigate the bandwidth limitation in the dual pump confi guration. We show that the minimum pulse width to be wavelength-converted without waveform distortion is proportional to the length of the LN crystal, and also reveal that that ratio is 1.6ps/cm. By utilizing this critical value as a performance metric, we demonstrate highly effi cient selective and tunable wavelength conversion of 40-Gbit/s data signals using a QPM-LN waveguide device with an optimum crystal length of 5cm.This device is quite attractive for channel-by-channel wavelength conversion in 40-Gbit/s dense WDM (DWDM) systems thanks to many excellent features such as wide range of wavelength tunability, high conversion effi ciency, modulation format free, adequate signal bandwidth and selectivity of 100-GHz-spaced DWDM channels.

Biography:

Ivan Bozovic received his PhD in Solid State Physics from Belgrade University, Yugoslavia, where he was later elected a professor and the Physics Department Konrad Altmann has completed his PhD in Physics from the Ludwig-Maximilian University of Munich, Germany, at 1975. The issue of his thesis was the quantum mechanical description of molecular spectra. For this work, he obtained the marking "with excellence". From 1976 to 1991 he was with the industrial company Messerschmitt-Bolkow-Blohm and developed a computer program for the description of a gas dynamic CO2 laser. From 1991 to 1993 he was with the German Aerospace and developed computer programs and published papers concerning laser beam propagation in the atmosphere. In 1993 he founded the company LAS-CAD GmbH with the purpose to integrate different simulation tools, necessary for the analysis of the multi-physics interaction in solid-state lasers, into the commercial program LASCAD. This program provides the laser engineer with the ability of a quantitative understanding of the complicated effects in laser systems. He has over 25 years of progressively responsible experience in computational physics especially in the fi eld of optics. He wrote more than 40 scientifi c publications in molecular physics, propagation engineering and laser technology and applied for 38 patents, of which 15 have been granted. He also wrote programs for the simulation of laser beam propagation in the atmosphere. In 2014 he was becoming Adjunct Professor of the National Engineering Center for DPSSL of the Chinese Academy of Science.

Abstract:

Th e computer program LASCAD provides a unique combination of simulation tools to optimize LASer Cavity Analysis and Design. Especially the following tools are available:

• Th ermal and Structural Finite Element Analysis of thermal eff ects in laser crystals
• ABCD Gaussian Beam Propagation Code taking into account thermal lensing, gain guiding, etc.
• Dynamic Analysis of Multimode and Q-switched operation analyzing the dynamic 3D behaviour of laser beams
• 3D Physical Optics Beam Propagation Code including diff raction, gain dynamics, etc.

An easy to use graphical users interface allows the combined use of these complex engineering tools. In this way, LASCAD helps the laser engineer to overcome the many interacting technical and physical problems he is confronted with when he develops a laser. Especially thermal lensing is of growing importance, due to the tendency to miniaturize laser systems, while
simultaneously increasing power output. Th e eff ect strongly depends on system characteristics, such as material parameters, resonator geometry, pump beam distribution and cooling layout. It interferes with gain dynamics, mode competition, Q-switching and other eff ects, which control beam quality and laser effi ciency in a complicated manner. Based on a numerical simulation of these eff ects, LASCAD™ provides the laser engineer with a quantitative understanding of the characteristics of a resonator design. Th e GUI of LASCAD, as shown in the fi gure, can be used as an optical workbench on the PC, allowing the intuitive design of laser resonators. In this way LASCAD™ helps users to process experimental results without wasting valuable time studying complicated manuals:

• Optical elements, such as mirrors, lenses or crystals can be added, combined, adjusted or removed by mouse clicks
• Astigmatism in the resonator and crystal is automatically taken into account
• Th e program menu makes available thermal fi nite element analysis, Gaussian ABCD matrix code, physical optics code, analysis of the Q-switched operation, computation of laser stability and power output.

Biography:

Baptiste Mot is a CNRS Research Engineer at the Institut de Recherche en Astrophysique et Planétologie (IRAP) in Toulouse. Since 2009 he is the Project Manager of the PILOT balloon-borne experiment. He is also in charge of the system engineering and of the ground end to end tests performed on the payload. He took part in the two fl ight campaigns in Timmins (Canada) and Alice Springs (Australia) and he works on this two fi rst fl ights' data analysis. He is involved in the conception of the satellite LiteBIRD that is the Class-L satellite mission proposed by JAXA, about to be selected by JAXA by the beginning of 2019. LiteBIRD is dedicated to the observation of the polarized emission from the CMB in order to measure the B-mode imprints of primordial gravitational waves from Infl ation. He is the System Engineer of the High-Frequency Telescope that is one of the two telescopes embedded on LiteBIRD.

Abstract:

PILOT (Polarized Instrument for Long wavelength Observations of the Tenuous interstellar medium) is a balloon-borne astronomy experiment designed to study the polarization of dust emission in the diff use interstellar medium in our Galaxy. Th e PILOT instrument allows observations at wavelengths 240μm and 550μm with an angular resolution of about two arcminutes. Th e observations performed during the two fi rst fl ights performed from Timmins, Ontario Canada and from Alice-springs, Australia, respectively in September 2015 and in April 2017 have demonstrated the good performances of the instrument. Pilot optics is composed of an off -axis Gregorian type telescope combined with a refractive re-imager system. All optical elements, except the primary mirror, which is at ambient temperature are inside a cryostat and cooled down to 3K. The whole optical system is aligned on the ground at room temperature using dedicated means and procedures in order to keep the tight requirements on the focus position and ensure the instrument optical performances during the various phases of a flight. We’ll present the optical performances and the fi rsts results obtained during the two fi rst fl ight campaigns. Th e talk describes the system analysis, the alignment methods and fi nally the in-fl ight performances.

Biography:

Fumihiro Dake, Senior researcher, Research & Development Division, Nikon Corporation, entered Nikon Corporation in 2009. He worked as an optical designer from 2009 to 2013. Then, he got to work on research of optical microscopy. He has researched and developed nonlinear optical microscopy.

Abstract:

In fluorescence microscopy, fluorescence lifetime information enables fluorophores with the same emission spectrums and diff erent lifetimes to be distinguished, which can improve molecular discrimination ability. Fluorescence lifetime generally depends on molecular conformation and the manner in which the molecule interacts with its environment, so that fluorescence lifetime imaging can reveal molecular interactions and dynamics at the molecular scale. We propose a time-domain approach for fluorescence lifetime measurements using nonlinear fluorescence microscopy constructed of two-color laser pulses. Our method is based on the pump-probe setup, where wavelengths of the pump and probe beams overlap the absorption spectrum and the fluorescence emission spectrum of the fluorescent dye, respectively and fluorescence wavelength to be detected is different from both wavelengths of incident beams. Nonlinear fluorescence signals generated by fluorescence reduction due to stimulated emission were detectable through a lock-in technique. The signal is produced by the multiplicative combination of incident beams, resulting in an improvement of the three-dimensional optical resolution. In the experiment, we modulated intensities of the pump and probe beams with frequencies of f1 and f2, respectively and demodulated the signal with f1–f2 to extract nonlinear fluorescence signal. Changing the time delay between the two-color pulses enables acquisition of a timeresolved nonlinear fluorescence signal, which directly refl ects the fluorescence lifetime of the sample and is thus applicable to fluorescence lifetime imaging. We also quantitatively demonstrate that nonlinear fluorescence microscopy possesses better optical resolution than conventional laser-scanning fluorescence microscopy. Experimental trials indicated that straightforward fluorescence lifetime imaging with high optical resolution is readily available.

Biography:

Caterina Gaudiuso received her Master Degree (cum Laude) and PhD in Physics from University of Bari (Italy) in 2011 and 2016, respectively. During her PhD, she spent a period of research as visiting PhD student at the Institut für Angewandte Physik of the Friedrich-Schiller-Universität Jena (Germany), under the supervision of Prof. S Nolte. She is currently a Postdoctoral Researcher at the Physics Department, University of Bari and her main research interest is laser ablation with ultrafast lasers. Her research is especially focused on the generation of bursts of picosecond-delayed sub-pulses, the study of the infl uence on the ablation process of the sub-pulse period within the burst and number of sub-pulses in the burst, the onset of damage process and the incubation effect. Recently, she has become interested in the use of bursts of sub-pulses for nano- and micro-structuring of materials, for varying the wettability and tribological properties of surfaces. The products of her research are 3 publications in peer-reviewed journals, 4 conference proceedings and 7 contributed conference presentations.

Abstract:

In this work, we report on an experimental study of the incubation effect during the irradiation of stainless steel with bursts of 650fs laser pulses at 1030nm. A series of birefringent crystals was used to split the pristine 650fs pulses into bursts of up to 32sub-pulses with time separations of 1.5ps and 3ps. Th e number of selected bursts was varied between 50 and 1600. In order to highlight the infl uence of the burst features on laser BM processing, the threshold fl uence was measured for each combination of the number of sub-pulses and time delays within the burst. Th e threshold fl uence in NPM was measured as well, to provide a comparison between the two processing modes. In BM, we found as many values of threshold fl uence as the combinations of the number of bursts and of sub-pulses constituting the bursts set to give the same total number of impinging sub-pulses, while in NPM the threshold fluence has a unique value, once the number of impinging pulses is fixed. Therefore, a dependence of the incubation coeffi cient with the burst features was hypothesized and experimentally investigated by assuming the incubation factor as a burst feature dependent coeffi cient. It was found that incubation effect is higher in BM than NPM and that it decreases with the number of sub-pulses n and for shorter time delays within the burst. Th e Two Temperature Model (TTM) has been adapted to the irradiation with single bursts of up to 4sub-pulses to interpret the experimental results.

Biography:

Madoka Ono has completed her PhD in the year 2004 from Tokyo University. Her PhD research was the study of optically excited states in low-dimensional Mottinsulators by using linear and nonlinear optical measurements. She joined Asahi Glass Company in the year 2004. Her researches since then were; 1. Electronemission properties of Calcium Aluminate electride 2. Improvement of the transmittance and laser-durability of silica glass 3. Study of the glass structures by positron annihilation measurements and 4. Optimization of glass composition and structures to obtain stronger glass with various strengthening processes. She is now working as a senior researcher and a project leader in AGC. She also works as a part-time lecturer of Yokohama National University, teaching glass science and its applications. She is a board member of photonics division of Japanese Society of Applied Physics.

Abstract:

Silica glass had long and intensively been studied due to its technological interest in manufacturing higher-performance optical fi bers. Recently, silica glass formed at high temperature and pressure is attracting much attention due to its physical properties which cannot be obtained by compression at room temperature. For example, the intermediate-range order structure of silica glass which was hot-compressed at several GPa around the glass-transition temperature (Tg ~1400K) was reported to be more homogeneous and is completely diff erent from that of silica glass compressed at room temperature, even though their densities were similar. Th e threshold pressure to trigger the change seemed to decrease with increasing temperature. We have previously reported that the Rayleigh scattering intensity in silica glass can be explained in terms of the voids in the glass behaving as scattering particles. Here, the expression of “void” stands for sub-nanometer size structural empty space, not bubbles. Th e void size was observed to decrease as the fi ctive temperature, Tf (temperature at which the glass network structure is “frozen”), decreased, by using positron annihilation lifetime spectroscopy. Th e decrease of the void size was found to suppress local density fl uctuations which, in turn, led to less intense light scattering. Th us, a decrease of the Rayleigh scattering intensity was expected if a reduction of the void size can be achieved. For industrial usage, pressures of less than 200MPa is desirable since samples of up to one-meter size are obtainable in a ready-made hot isostatic pressure (HIP) machine. Th erefore, we investigated the Rayleigh scattering intensity of hot-compressed silica glass using HIP under its melted phase. As a result, the optical transport properties of the silica glass was largely improved by the process. The lowest Rayleigh scattering loss was obtained for the glass held at 200MPa and 2073K for 4h. Th e observed loss corresponds to 0.07dB/Km at 1.55m, which is about half of the loss in conventional silica glass fi ber. Th e decrease in the loss was well explained in terms of the decrease in the size of the sub-nanometer-sized structural voids. Due to the compressive stress, the refractive index increased simultaneously with the decrease in the void size and the scattering intensity. Th is is very favorable for fibercore media, where high transparency and strong confi nement of light are desired. It is not possible to otherwise get such glass homogeneity (corresponding to such a low Tf) and reduce the Rayleigh loss simply by thermal engineering at standard atmospheric pressure.

Biography:

Xingjun Wang received the BE, ME and PhD degrees from the Dalian University of Technology, China in 1999, 2002 and 2005 respectively. From 2007 to 2009 he was a JSPS Postdoctoral Fellow in the Department of Electronic Engineering, University of Electro-Communications, Japan. In 2009, he joined Peking University and is currently a Full Professor at Peking University, Beijing, China. In 2015, he was selected fi rst Young Yangtse Rive Scholar of China. Now he is devoted into Siphotonics, including the Si-based light source and Si optoelectronic integration chip for high-speed optical communication. He has published more than 150 papers on international journals and conference proceedings. The 80 papers have been SCI indexed. The citation reaches 800 times.

Abstract:

In the process of information technology, as Moore's law becomes more and more close to the limit, it has become inevitable and the consensus to combine microelectronics and optoelectronics to develop silicon-based large-scale optoelectronic integration technology. As the most important part of silicon photonic devices, silicon-based light source still attracted great eff orts. In the traditional research, the erbium-doped materials have played an important role in silicon-based light sources. Recent studies demonstrated that the erbium silicate compound had a high net gain attributable to its high erbium concentration that has no insolubility problem. This paper focuses on the theory, designs, simulations, preparation methods, process and device optimizations of the erbium silicate compound optical waveguide amplifi er and laser. The erbium silicate compound materials with large optical gains can serve as potential candidates for future silicon-based scale-integrated lightsource applications.

Biography:

Fansheng Chen has completed his PhD in the year 2007 from SITP (ShangHai Institute of Technical Physics of CAS). He is the Professor of SITP, a premier optical remote sensing instrument organization. He has published 32 papers in the main academic journals and authorized 10 patents.

Abstract:

The infrared system used for weak point target detection has high encircled energy and the accurate measurement of the intra-pixel response is the key to realize high-precision radiation calibration and combined positioning of the detection system. A variety of test methods have been established to measure the intra-pixel response in the visible detector pixels, such as the spot scan with the microscopy system. However, there are few types of research about the test method of the intra-pixel response of infrared detectors due to its location in the Dewar cold space. In this paper, an intra-pixel response test method for high encircled energy infrared detection photoelectric system is proposed and a mathematical model for intra-pixel response calculation is established. Th e test system consists of a small hole that simulates a point target, a collimator, a turntable and an optical system of the infrared detection system itself. Th e PSF of the optical system is restricted. Based on the established model, the intra-pixel response parameters of the detector's pixels are calculated by the method of grid search and optimized by the cross-validation method. Several pixels are selected to test and the data is collected by scanning 10×10 spots in a single pixel with a diff erent radius of holes. Th e same pixel in the detector is tested with small holes of diff erent radius, the consistent intra-pixel response and PSF of the optical system are obtained, which proves the eff ectiveness of the method. Finally, the internal response function was verifi ed by the geometric positioning method and the error was within 8%.

Biography:

Seiji Okamoto received the BE, MS and PhD in Electrical Engineering from Tohoku University in 2009, 2011 and 2018 respectively. In 2011, he joined NTT Network Innovation Laboratories, Yokosuka, Japan, where he has been engaging in the research and development of the large capacity and low power digital coherent optical transmission systems with high-speed digital signal processing.

Abstract:

Due to the introduction of digital coherent technology which enables us to employ multi-level modulation such as Highspectral-effi ciency (SE) quadrature amplitude modulation (QAM), the capacity over the single mode optical fi ber has dramatically increased in limited wavelength resources. In a deployed network, polarization-division-multiplexed (PDM) 16QAM signal of which amplitudes modulated with 4 levels began to be widely used using the real-time digital signal processor (DSP) and the SE was 5.3bit/s/Hz. As for the highest-order QAM transmission in the laboratory, the PDM-4096QAM signal was successfully transmitted using an optical phase-locked loop (OPLL) technique and the potential SE was reached 15.8bit/s/Hz. Further higher SE can be realized by utilizing the higher-order QAM, however, it needs much fiber amplitude modulation level and results in the reduced noise tolerance. Meanwhile, the probabilistic shaping (PS) or constellation shaping has been intensively investigated because it off ers ultimate shaping gain of 1.53dB and enables to reach the Shannon limit in additive white Gaussian noise channel. PS modifi es the probability of the amplitude points on the QAM constellation into approximately Gaussian distribution, thus the lower power points are generated more often than the points with a higher power. The amplitude probabilities of PS-256QAM and uniformly-shaped (US) 64QAM signals and is the generalized mutual information (GMI) which represents the transmission rate per received symbol in each polarization. Th e GMI of the PS-256QAM exceeded that of the US-64QAM and can realize the close performance with Shannon limit. In order to realize a high SE transmission with a high noise tolerance, the combination of the high-order QAM and the PS technology has attracted much attention. A single channel 82 Gbaud PS-256QAM transmission with SE of 8bit/s/Hz was achieved over 400km by precisely compensating the frequency response of the transceiver. As the highest-order PS-QAM experiments, single channel 3 Gbaud PS-4096QAM with SE of 15.3bit/s/Hz was fi rstly demonstrated over 160km. Th en, 10 wavelength-division-multiplexed (WDM) 3 Gbaud PS-4096QAM transmission with SE of 17.3bit/s/Hz was realized over 50km. In this paper, we review the recent transmission techniques to generate the signal applied with the high-order QAM and the PS. Th en the numerical performance comparison between PS and US constellations in terms of phase noise is presented. We also describe the experimental results of 80 Gbaud PS-256QAM transmission with precise calibration technique as the transmission with the large capacity and 3 Gbaud PS-4096QAM transmission with OPLL as the transmission employing largest constellations. Th e SE of each transmission was 8 and 15.3bit/s/Hz, respectively. Lastly, we discuss the challenges to further increase the SE.

Biography:

Sunggoo Cho completed his PhD in the year 1989 from University of Maryland, College Park, USA. As a student of the physics department, he wrote his PhD thesis on “supermanifold” under the supervision of Dr P Green in the department of mathematics. After Post-doctoral research at Sogang University, South Korea, he had worked as a Professor at the Department of Physics of Semyung University from 1991 to 2005 as a pure mathematical physicist. Now he is a Professor at the School of Computer Science of Semyung University teaching game programming and deep learning. He has developed a couple of commercial software with a team of students. In addition, he is a researcher and developer at the Light and Math Inc. at Semyung University and has more than 20 patents. He has also developed several computer programs for optical applications such as interferometer program with noisy fringe patterns for Prooptics Inc. in South Korea. He has executed more than 15 commercial projects for several companies. He is currently working on deep learning and its applications to optics and computer vision.

Abstract:

Parabasal theory is a technique in geometrical optics that describes the behavior of light rays located near some defined base ray rather than the optical axis. In this work, we are concerned with parabasal rays which lie in a sufficiently small neighborhood of a chief ray and develop some formulas for parabasal quantities of the chief ray. Parabasal quantities of a chief ray are shown to be intimately related to the coeffi cients of fi rst order differential equations of the chief ray. Using the relations, we derive parabasal formulas containing parabasal refractive indices and parabasal powers from the first order differential equations. Th ese parabasal formulas turn out to be decoupled diff erential equations of the fi rst order diff erential equations so that highly coupled diff erential equations for a chief ray can be solved systematically. In addition, we apply parabasal formulas to the paraxial region by taking the limits of the formulas. Th ese limits give necessary conditions expressed in terms of Gaussian brackets for various initial design requirements of optical lens systems. Th ose necessary conditions do not seem to be derivable by using only paraxial theory without parabasal approaches developed in this work.

Biography:

Guo-Dung J Su had his BS degree from National Taiwan University in 1994. He then joined the University of California, Los Angeles and received and his MS and PhD in electrical engineering in 1998 and 2001 respectively. His Doctoral research interest is related to MEMS scanners with a fl at mirror surface for active optical alignment and micromirror arrays for adaptive optics applications. Since 2004, he became an Assistant Professor at Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering of National Taiwan University. His current researches include Optical system design, MEMS devices for optical communications, compact optical imaging systems and surface plasmon phenomenon on nanoparticles.

Abstract:

In this talk, we present a narrow spot headlamp system of the dual half circular parabolic aluminized refl ector (PAR). This system has a property that each of the half-circular PAR contains fi ve high-effi ciency and small package light emitting diode (LED) chips with 180o rotational symmetry. Concerning traffic safety, the design criterion of train headlamp is to meet the code of Federal Regulations (CFR). In terms of the forecast of illuminated position on a screen, analytic derivation has been developed to study the optical path of a ray which is perpendicular to and emitted from the center of the LED chip. This ray stands for the main emitted ray of the LED chip and it is inside of the illuminated spot by the LED source on the screen. Therefore, we can analyze design systematically for determining where the LED chips ought to be placed in the PAR reflector for minimizing electricity consumption while satisfying the reliability constraints on train headlamp to ensure traffic safety. Compared to a typical train headlamp system with incandescent or halogen lamp needing several hundred watts, the proposed system only uses 20.18W to achieve the luminous intensity requirements. Compared with the typical train headlamp system incorporating incandescent or halogen lamp with a power rating about 200 to 350W, the proposed system only uses 20.18W to achieve the luminous intensity requirements. If the train headlamp turns on 8 hours a day, one year can save electricity about 584kWh (=0.2kW8h/d365d). If electric power is generated from crude oil, according to the estimation of 0.26kg CO2/kWh in the literature, the proposed approach can eff ectively lower down about 152kg CO2 emission per year for a single lamp.

Biography:

Yong Han has completed his PhD (Major: Optics) in the year 2007 at the age of 32 years from the key lab of atmospheric optics, Anhui Institute of Optics and Fine Mechanics, Hefei Institute of Physical Science, Chinese Academy of Sciences. He has completed his post-doctoral (Major: Atmospheric Sciences) in the year 2010 at the age of 35 years from Key Laboratory of Middle Atmosphere and Global Environment Observation (LAGEO), the Institute of Atmospheric Physics, Chinese Academy of Sciences. Before 2017, he was an associate professor at the School of Atmospheric Science, Nanjing University. Now, he is a Professor of School of Atmospheric Sciences, Sun Yat-Sen University, an important scientific and talent training university. He teaches the undergraduate core course earth atmosphere integrated exploration and graduate courses radar and satellite. He has published more than 55 papers in reputed journals, two international invention patents, monographs of the editor in chief (the Principle and Method of Detection in Atmospheric Science) and has been serving as an member of the Atmospheric Exploration and Instrumentation Committee of China Meteorological Society, Youth Director of China Particle Society, Specialized Committee Member of Jiangsu Meteorological Society and Director of Jiangsu Particle Society, China, etc. His research interests are the study of Atmospheric Physics and Atmospheric Exploration, Atmospheric Remote Sensing and Atmospheric-ocean Optics, Atmospheric Composition and Observation Scientific Instruments.

Abstract:

The optical properties, time-height distribution and impact on the local air quality from a heavy Asian dust transport episode are investigated with a synergistic ground-based, satellite sensors and model on May 2011 in Nanjing city (32.05°N,118.78°E, 94m ASL), China. Two dust layers located in the planetary-boundary-layer (PBL, <2.5km) and free troposphere (3–6km) are observed by a Polarization Raman-Mie Lidar. Diff erent transport paths originating from the Gobi deserts and Taklimakan deserts are demonstrated by the NOAA HYSPLIT, NAAPS models and NASA satellites (MODIS and CALIPSO) imageries. Th e dust aerosol layer shows the depolarization ratios at 0.1–0.2 and strong extinction coeffi cients attaining 1.0km-1 at 532nm and the Lidar ratios of dust are 47.3–55sr below 2.5km altitude. During this dust intrusion period, the aerosol optical depths (AOD) dramatically increase from 0.7 to 1.6 at 500nm whereas the Angstrom exponents decrease from 1.2 to 0.2 according to the Cimel-sunphotometer measurement. Meanwhile, both surface PM10 and PM2.5 concentrations show similar temporal variation and a signifi cant increase with the peak value attaining 767g/m3 and 222g/m3 respectively. Regional influences of the transported dust are further illustrated by the AERONET-sunphotometer observations at Taihu and Xianghe sites (downwind and upwind from Nanjing), satellites MODIS, CALIPSO and model products in east China. In addition, we also discussed the agricultural biomass burning (ABB), which has been of particular concern due to its influence on air quality and atmospheric radiation, as it produces large amounts of gaseous and aerosol emissions. This study presents an integrated observation of a signifi cant ABB episode in Nanjing, China during early June 2011, using combined ground-based and satellite sensors. The time-height distribution, optical properties, sources and transport of smoke, as well as its impacts on air quality are investigated. Lidar profi les indicate that the smoke aerosols are confi ned to the planetary-boundary-layer (PBL) and have a depolarization ratio of less than 0.08. Th e aerosol optical depth (AOD) increases from 0.6 to 3.0 at a wavelength of 500nm, while the Angstrom exponent varies from 1.0 to 1.6. Th e aerosol single scattering albedo becomes smaller (0.87-0.8) at 675-1020nm and shows a decreasing trend from the wavelength of 440nm to 1020nm, indicating more absorbing aerosols. The absorption Angstrom exponent (0.7) is smaller than 1.0, which may indicate the aged smoke particles mixed or coated with the urban aerosols. By combining MODIS fire, AOD, CO from AIRS and NO2 from OMI products, the ABB sources are identified in mid-eastern China. Surface PM10 and PM2.5 show a dramatic increase, reaching 800g/m3 and 485g/m3, respectively.`

Biography:

Tang Xiahui is a professor and doctoral supervisor of School of Optical and Electronic Information at Huazhong University of Science and Technology. He is presently the vice-director of the National Engineering Research Center for Laser Processing and he is the executive member of the council of Hubei mechanical engineering society and laser processing committee of the Chinese Optical Society, the vice-chairman of Laser Institute of Hubei Province, the editor of “Laser Technology” and “Applied Laser”. His interested areas are high power CO2 gas Laser, high power laser processing systems integration, welding, brazing, cutting and surface engineering. He published more than 60 papers in the domestic and foreign academic journals, more than 20 papers were SCI, EI, ISTP included and Obtained 5 Chinese invention patents. He received Hubei Science and Technology Progress Award in 2004 and Ministry of Education, National Science and Technology Progress Award nominations in 2005. He has fi nished the MOST National “Fifteen” Scientifi c Technological Research Plan, “Eleventh Five” major scientifi c and technological support plan, Doctoral Fund of Ministry of Education, Hubei Province “Eleventh Five-Year” key scientifi c and technological and NSFC, respectively. Further, he undertook nearly 60 enterprises of science and technology projects.

Abstract:

When the ultra-short laser pulse is used for the plasma acceleration, the energy transferring to the charged particle is proportional to the product of the field intensity and the square of the wavelength. Due to its mid-infrared wave band(10.6μm), CO2 laser is likely to be one of the most important next generation light source for the laser acceleration of proton and ion. However, due to the discretization and narrow bandwidth of the gain spectrum of CO2 molecules, it is hard for the chirped pulse amplifi cation being used for the CO2 laser. Th is project proposes to increase the gain of CO2 molecules sequence band using optical pumping and compact the gain spectrum by means of overlapping gain spectrum of sequence band and normal band to solve the problem, realizing pico-second CO2 pulse amplifi cation at quasi-continuous spectrum. The team will carry out the researches about the absorption spectrum of sequence band, the energy relaxation at each rotational level of the optical pumped sequence band, the coherent amplifi cation process of diff erent spectrum of the input pulse in the different gain band series both theoretically and experimentally. Establishing a synthesis analytical model of a quasi-continuous spectrum CO2 laser amplifi cation matching electro-optic pump, roundly analyzing infl uence of gain of CO2 sequence band on performance characteristics of the amplifi er, building pulse discharge CO2 laser amplifi er with innovative structure and high effi ciency pumped by solid-state laser, obtaining laser output at ps-mJ level, Laying the theoretically and experimentally foundation for picosecond-Terawatts CO2 laser system.

Biography:

Zhuoyue Hu has completed her undergraduate study in the year 2016 from UESTC(University of Electronic Science and Technology of China). She is studying in the SITP(Shanghai Institute of Technical Physics of the Chinese Academy of Sciences) for a PhD.

Abstract:

In view of the radiometric calibration of large aperture optical systems, a parallel light coupling method is proposed to achieve non-uniformity correction and radiometric calibration through the internal blackbody into the optical path. The sensor consists of two parts, the front optical system and the rear optical system. Between the front optical system and the rear optical system is connected by parallel light, which is the characteristic of this calibration system. Its calibration system includes image space blackbody and calibration mirror. In this paper, the relative radiation calibration is realized by an internal blackbody. We establish a response database with integral time and blackbody energy as a variable and a nonlinear nonuniformity correction algorithm based on variable integration time and variable energy are adopted to achieve the relative radiometric calibration of the image. Th rough the non-uniformity correction algorithm, we get the result which is better than 0.2%. It shows a better result than the two-point correction and multi-point correction. We also use the star and internal blackbody to monitor the stability of the camera, we chose the star which satisfi es the Radiation theory, it is easy to find the star and simplify the process. By comparing with the internal blackbody calibration, the calibration method based on the WISE star table can achieve the calibration accuracy better than 10%. We found that the system stability result of the back optical is within 3% and the front optical is within 5% for 8 months. According to the requirement of calibration precision, the frequency
of calibration is designed.

Biography:

Tong Hoang Tuan was born in Ho Chi Minh City, Vietnam, in 1985. He received his MS degree in Applied Physics from the University of Science, Ho Chi Minh City, Vietnam in 2010 and PhD degrees in Future Industry-Oriented Basic Science & Material Engineering from Toyota Technological Institute, Nagoya, Japan in 2015. Since then, he joined the Laboratory of Optical Functional Materials, Toyota Technological Institute, as a post-doctoral fellow. His special technical skills are involved in glass material development, fi ber characterization and fabrication using highly nonlinear materials. In 2017, he received the KAKENHI research fund supported by Japan Society for the Promotion of Science (JSPS). His current research interests include the fabrication and characterization of chalcogenide and tellurite buffer-embed hybrid microstructure optical fi bers for broadband mid-infrared supercontinuum generation, fi ber optical parametric amplifi cation and frequency comb generation, the dynamic photonic bandgap control of novel all-solid photonic bandgap fi bers for ultrafast optical modulation, the hollow-core photonic crystal fibers and the infrared optical image transport in novel tellurite optical fi bers with transversely disordered refractive index profi le.

Abstract:

In recent years, the development of high capacity and broad transmission optical systems and devices for global telecommunication networks is rapidly increasing due to the explosive spread of telecommunication devices such as smartphones and computers. Along with the development of broadband optical systems, the demand for optical amplifiers at many diff erent wavelengths in the telecommunication range are also growing. Although Erbium-doped fiber amplifiers (EDFA) are widely used as gain media for wavelength division multiplexing (WDM) systems, their gain bandwidths are as narrow as 30nm from 1530 to 1560nm. In a nearby wavelength range, optical fi ber amplifiers operating near 1.3μm in the telecommunication band where conventional single-mode fi bers have low-loss and low dispersion are very attractive. Among several active rare-earth ions that have been investigated for optical fiber amplifi ers operating near the 1.3μm spectral region, Nd3+ is a potential candidate for compact and highly effi cient optical fi ber amplifi ers even with a short fi ber length of a few centimeters due to its 4F3/2→4I13/2 transition. However, the use of the 1.3μm emission in a practical Nd3+-doped fi ber has faced with several problems. One of its major problems is the presence of competing amplifi ed spontaneous emission (ASE) at 1.06μm due to the 4F3/2→4I11/2 transition whose branching ratio is about 5 times larger than that at 1.3μm. In order to realize a practical optical amplifi er device at 1.3μm, the ASE at 1.06μm must be fi ltered out. In this work, we propose a tellurite all-solid photonic bandgap fi ber (ASPBGF) to fi lter out the competing emission at 1.06μm which is most prominent in the emission spectrum of the Nd3+ ion. A novel Nd3+-doped tellurite ASPBGF is fabricated by using our developed tellurite glasses which have high compatibility of thermal properties and their refractive index diff erence is 0.096 at 1320nm. The fiber is designed with 4 layers of high-index rods to have low confi nement loss. Th e measured transmission spectrum of a 2.2cm long section of the fabricated fi ber exhibits high transmission bands near 0.75 and 1.33μm (about -20dB and -19dB) and a low transmission band in the vicinity of 1.06μm which is about -27dB. By using our fabricated Nd3+-doped tellurite ASPBGF, it is demonstrated for the fi rst time that the 1.06μm emission peak due to the 4F3/2→4I 11/2 transition of Nd3+ ions is greatly suppressed about 12 times as compared to that obtained by using a bulk samples with the same doping concentration.

Biography:

Peiqi Zhou has completed his Bachelor's degree in the year 2016 at the age of 22 years from Wuhan University, Wuhan, China. He is now a PhD student of Prof Xingjun Wang from Peking University, Beijing, China. He has published about 2 papers on international journals and conference proceedings.

Abstract:

In recent years, erbium silicate compound has aroused considerable research as erbium-based materials for small size and high gain light sources in silicon photonics integration, since it contains a high erbium concentration that has no insolubility problem. In addition, ytterbium cations are usually added to the erbium silicate to prevent neighboring erbium ions from causing cooperative upconversion and also act as sensitizers. Methods have been utilized for depositing erbium-ytterbium silicate fi lms include the sol-gel method, sputtering and pulsed laser deposition. Compared with other deposition methods, magnetron sputtering has the advantages of fast deposition rate, high purity, good compactness, good uniformity and strong controllability which has gained rapid development and wide application. There are three main sputtering methods for erbiumytterbium silicate fi lms: co-sputtering, multi-layer alternating sputtering and mixed-target sputtering. Although each of them has its own advantages and disadvantages, their systematical researches and comparisons are not enough. In this paper, a series of erbium-ytterbium silicate fi lms with diff erent compositions were prepared by co-sputtering, multi-layer alternating sputtering and mixed-target sputtering. Several analysis and optimization of the fi lms were given to systematically compare three diff erent sputtering methods, which includes the photoluminescence intensity, crystal structure and luminescence lifetime. The results have laid the foundation for the erbium silicate light source devices preparation.

Biography:

Hehai Fang received his Bachelor degree with honors in condensed matter physics from Nankai University, China, in 2014. He is now pursuing a PhD degree in Microelectronics and Solid-State electronics at the Shanghai Institute of Technical Physics (SITP), Chinese Academy of Sciences (CAS). He got the National Scholarship for outstanding PhD students in 2017. His research interests are in fabrication and characterization of infrared photodetectors based on low dimensional materials, including nanowires, 2D materials and nanostructured semiconductors with narrow bandgaps.

Abstract:

Indium arsenide nanowires (InAs NWs), have been widely researched in recent years together with other III-V semiconductor NWs like InP, GaN, InSb etc. With a high mobility and a direct narrow bandgap (approximately 0.35eV), InAs NWs seem to be more appropriate for applications of high-speed electronic components and broad-spectrum detection media. Photodetectors based on single InAs NW and NW arrays have been successfully fabricated and exhibit a good photoresponse. Research has identified two diff erent photodetection mechanisms for single InAs NW photodetector, which are positive photoresponse (PPR) and negative photoresponse (NPR) respectively. Th e diff erence between these two mechanisms is that the latter is a phenomenon induced by surface states similar to a photo-gating layer (PGL) trapping hot electrons and seems to work only when the energy of an incident photon is much higher than the bandgap of InAs. For NPR, an ultrahigh photoconductive gain of -105 and a response time of less than 5ms have been achieved. While for PPR, the responsivity and detectivity reach 5.3×103A/W and 2.6×1011 Jones, which is also a high performance. However, most reported work about InAs NW-based photodetectors is limited to the visible waveband. Although some work shows the certain response for near-infrared light, the problems of large dark current and a small light on/off ratio are unsolved, thus signifi cantly restricting the detectivity. Here in this work, a novel “visible light-assisted dark-current suppressing method” is proposed for the fi rst time to reduce the dark current and enhance the infrared photodetection of single InAs nanowire photodetectors. Th is method eff ectively increases the barrier height of the metal-semiconductor contact, thus signifi cantly make the device a Metal-Semiconductor-Metal (MSM) photodiode. Th ese MSM photodiodes demonstrate broadband detection from less than 1 μm to more than 3μm and a fast response of tens of microseconds. A high detectivity of ~1012 Jones has been achieved for the wavelength of 2000nm at a low bias voltage of 0.1V with the corresponding responsivity of as much as 40A/W. Even for the incident wavelength of 3113nm, a detectivity of ~1010 Jones and a responsivity of 0.6A/W have been obtained. Our work has achieved an extended detection waveband for single InAs NW photodetector from visible and near-infrared to mid-infrared. Th e excellent performance for infrared detection demonstrated the great potential of narrow bandgap NWs for future infrared optoelectronic applications.

Biography:

Ciro Dantas Soares has completed his MSc in the year 2015 at the age of 22 years from University of Campinas, Brazil. Currently, he is PhD training in progress in Oral Pathology of University of Campinas and LA Biomedical Research Institute. He has published more than 20 papers in reputed journals and has been serving as an editorial board member of repute.

Abstract:

Photobiomodulation therapy (PBMT) is the most recent term for the Low-Level Light Th erapy in the MeSH data. As stated by Anders et al. photobiomodulation is defi ned as “A form of light therapy that utilizes non-ionizing forms of light sources, including lasers, LEDs and broadband light, in the visible and infrared spectrum. It is a nonthermal process involving endogenous chromophores eliciting photophysical (i.e. linear and nonlinear) and photochemical events at various biological scales. This process results in benefi cial therapeutic outcomes including but not limited to the alleviation of pain or infl ammation, immunomodulation and promotion of wound healing and tissue regeneration”. The use of PBMT in wound healing lacks mechanistic in vivo assays to determine the pathways activated during the diff erent phases of repair. We will present new data regarding the expression of fi broblast growth factors (FGF) under skin and bone wounds treated with various sources of PBMT. It was demonstrated that PBMT modulates the levels of basic FGF, particularly and consequently, acts activating important pathways of angiogenesis, cell survival and proliferation in models of skin and bone wound healing. In addition, PBMT improves bone repair in female rats with osteoporosis by decreasing the number of neutrophils, monocytes and osteoclast. In summary, the modulation of FGF2 seems to be an important step in the PBMT-based repair and also PBMT improves wound healing by enhancing neocollagenesis, increasing the number of new vessels formed in the tissue (neoangiogenesis) and modulating matrix metalloproteinase-2 expression and as expected, PBMT stimulated bone repair in female rats with osteoporosis and slightly decreased the infl ammatory response.

Biography:

Yuzhen Liang hails from Xiamen, China. She is currently an undergraduate student of photoelectric information science and technology at the Xiamen University of Technology. Her industry experience includes working as an optical assistant at Xiu Yu Incorporated in Taiwan. In this capacity, she helped develop ultra short-focus projection and laser projection technology. At the same time, she worked on the development of automated vehicle systems with regards to visual recognition and produced a smart mattress care system. Her most recent work focuses on the optical engineering of a new keyboard projector.

Abstract:

Optical metamaterials can achieve an unconventional eff ective index of refraction by engineering the geometry of the building blocks. In extreme cases, the eff ective index can approach zero, resulting in infi nite phase velocity and spatial wavelength. However, because of the zero index corresponds to an electric monopole mode and two magnetic dipole modes degenerating at the center of the Brillouin zone, which is innately above the light line, opening a loss channel to the direction perpendicular to the substrate, i.e. the guided wave propagating within the zero-index metamaterial can couple to a planewave radiating in the out-of-plane direction (the direction perpendicular to the substrate). Here we eliminate this out-of-plane radiation loss via the destructive interference between the plane waves radiating upward and downward, forming a bound state in the continuum. A zero-index metamaterial design with a refl ector that reduces radiation loss through the destructive interference of multiple lossy channels, resulting inbound states in the continuum. Th e design includes a silicon pillar array and a planar reflector. By adjusting the distance between the refl ector and the pillars, out-of-plane radiation can be eliminated completely. However, for near zero-index metamaterials (ZIMs), there is no similar design and method to reduce the out-ofplane radiation losses. We design a low-loss near zero-index metamaterial composing of an array of silicon pillars without a reflector. Under an in-plane TM excitation, the pillars support two Bloch modes at the center of the Brillouin zone: an axial electric monopole mode, and a transverse magnetic dipole mode. By adjusting the radius and pitch of the pillar array, we can achieve the degeneracy of these modes at the center of the Brillouin zone and a given operating wavelength, in our case 1525nm.

Biography:

Hye Mi Cho had a BS in Materials Engineering and a Master of Ceramic Engineering degree. So, as a structural analysis expert, I am doing analysis work to help research.

Abstract:

Recently, quantum dots have been investigated as promising optoelectronic materials because of its unique optoelectronic properties and high stability compared with bulk material by quantum confi nement eff ect. Quantum dots have been studied to solve the limitations of commotional optoelectronic device. For example, the luminescence wavelength can be shift ed to a visible wavelength range with quantum dots. Th erefore, quantum dots optoelectronics can be applied into not only biochemical applications but also light emitting diodes (LEDs), laser and fl uorescent biological label. The composite semiconductor nanocrystals such as CdS, CdSe and ZnSe have been studied for photoluminescent quantum dots materials. Above all, CdSe is advantageous materials because it has bright luminescence in the visible range of the optical spectrum and easily fabricable in well-dispersed nano-sized crystals. The properties of CdSe quantum dots core such as reaction temperature, concentrations and time can be varied using the synthetic parameters. The most of cases, CdSe quantum dots were synthesized by a colloidal process with phosphine (PH3) precursor such as TOP, TOPO and TBP. However, conventional colloidal methods with PH3 were suitable, hazardous and pollutive. In this study, quantum dots are successfully synthesized using phosphine-free colloidal method under various conditions is confi rmed to control surface properties. In order to evaluate the size dependence of CdSe crystal, synthesis temperatures were changed from 2400C to 3000C and precursor ratio (Cd:Se) was controlled. The optical properties of the synthesized CdSe quantum dots were confi rmed using photoluminescence (PL). Th e microstructure and phase developments were measured by transmission electron microscopy (TEM) and X-ray diff ractometer (XRD) respectively.

Biography:

Jinwoo Lee is currently a PhD candidate at Seoul National University in South Korea after he completed his master degree at KAIST. His research of interest is laser-induced material growth, laser sintering of materials for functionalization and fabrication of energy storage/harvesting device.

Abstract:

Exploration of the electronics solely comprised of bottom-up synthesized nanowires has been largely hindered due to the complex multistep integration of diverse nanowires. In this research, we report the demonstration of on-demand selective laser integration of secondary heterogeneous branched metal oxide NWs on a primary backbone metal NW in a highly selective manner based on a heater-assisted laser-induced hydrothermal growth (LIHG) process. Th e most widely studied NWs, silver (Ag) and zinc oxide (ZnO) NWs, are selected as the primary backbone and secondary branch NWs respectively. The highly localized and instantaneous temperature elevation by laser irradiation on the primary backbone metallic nanowire generates a nanoscale temperature fi eld followed by a photothermal reaction to selectively grow secondary branch nanowires along the backbone nanowire. An ultraviolet photo-sensor based on the proposed selective laser grew ZnO NW branch on an Ag NW backbone is further fabricated as the simplest form of proof-of-concept for all nanowire electronics and demonstrates its potential as future electronics with compact size, low power consumption and fast response. Scanning electron microscopy and numerical simulation were employed to analyze the general morphology of hierarchical heterogeneous nanowires and scrutinize the laser polarization eff ect of the laser utilized in this report on an Ag nanowire with its cross-section respectively. We expect that the proposed process can be further extended to other various material combinations whose hydrothermal growth routes are known. With a broader range of applicable nanowires, the proposed process shows great promise in the bottom-up fabrication of all-nanowire nanoelectronics, such as multifunctional environmental sensors.

Biography:

Nu Si A Eom has completed PhD in the year 2017 at the age of 30 years from Hanyang University in Korea. Her master’s project was “Synthesis and Characterization of CdSe based Quantum Dots” and her PhD project was “New approaches for improving SnO2 and silicon-based semiconductor gas sensor at room temperature by micro/nano hybridization” in Korea. She has published several articles in SCI journal. Her main academic interests are quantum dot and semiconductor gas sensor. In 2018, Her current research concerns magnetic materials in Korea Institute for Rare Metal, Korea Institute of Industrial Technology.

Abstract:

The development of permanent magnet materials has led to the demand for innovative technologies such as electric motors and generators for energy conversion devices. Especially, The hard magnet materials based on NdFeB have been applied to wide areas such as automobiles, electrical devices and magnetic disks due to their excellent magnetic properties. The NdFeB including the transition metals such as Fe has also magneto‐optical eff ects. NdFeB based magnetic materials were generally synthesized using the classical powder metallurgy process. However, it was difficult to align easy magnetization axis (c-axis) and to obtain homogeneous microstructure for enhancing magnetic performances. Th ere has also been little signifi cant research on one-dimensional Nd-Fe-B magnetic synthesizing c-axis alignment. In this study, one-dimension NdFeB materials having c-axis alignment were facilely prepared through electrospinning process. In order to confirm magnetic properties with wire diameter, synthesis conditions were controlled by PVP volume. Th ese Nd-Fe-B fi bers had the diameter within a range from 700 to 1300nm. Th ese metal oxides polycrystalline fi bers were subsequently heat treated in the high vacuum furnace in the presence of the calcium as a reducing agent, resulted in Nd2Fe14B fi bers. Th e morphology of the synthesized Nd-Fe-B material was 1300nm analyzed by fi eld emission scanning electron microscope (FE-SEM) and X-ray diff raction (XRD). Th e magnetic property as a function of Nd-Fe-B wire diameter was conducted using vibrating sample magnetometer (VSM). Th e coercivity (Hci) of Nd2Fe14B fi bers was about 4800Oe. Th e values of saturation magnetization (Ms) and remanence (Mr) of fibers were 45emu/g and 20 emu/g.

Biography:

Yi Zhu has completed his PhD in the year 2013 at the age of 29 years from Royal Institute of Technology. He is an associate professor in the department of mechanical engineering at Zhejiang University. He has published more than 25 papers in reputed journals and has been serving as an associate editor of Journal of Tribology.

Abstract:

In selective laser melting (SLM), processing parameters are of a great importance which aff ects the amount of laser energy absorbed by metal powders. On one hand, the mechanical properties of the processed part depend on them. On the other hand, processing parameters also aff ect power profi le and scanning time, which directly relates to electrical energy consumption. In this research, we investigate the correlation between electrical energy consumption and mechanical properties and study whether electrical energy can be eff ectively reduced without signifi cantly compromising mechanical properties by optimizing processing parameters. 316L stainless steel was used as powder materials. Two key parameters, laser power and exposure time, were selected and several mechanical properties, including density, hardness, wear resistance, tensile strength, flexural strength and torsional strength, were tested. Th e results of electrical energy consumption and mechanical properties were jointly analyzed using growth rate comparison. It was found that the improvement of various mechanical properties with increased electrical energy consumption diff ers greatly. Density can be eff ectively increased without signifi cantly increasing the electrical energy, but the electrical energy needs to be greatly increased in order to achieve a high fl exural strength. Growth rate three-dimensional maps of mechanical properties and electrical energy consumption are presented as a reference for processing parameter optimization.