5^th International Conference and Exhibition on Lasers, Optics & Photonics November 28-30, 2016 Atlanta, Georgia , USA

Biography:

Douglas R McCarter, Drhc, is the Technical Integrator of McCarter Machine & Technology Inc., founded in 1981. His 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, Missile Defense Briefs Open and Classified, 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, Congressman District 37 and Leader of NASA Funding, endorsed him, and the staffers are working directly with backing of the development of McCarter Silicon Space Systems. In addition to over 3000 hours of Technical Schools, he has been directly mentored by the late Frank Anthony, Bell Labs and Roger Paquin Perk & Elmer, a retired Materials Expert.

Abstract:

Most high energy lasers use single crystal silicon for the mirrors only, up to 460 mm diameter. McCarter has developed an all single crystal silicon telescope model that incorporates modular single crystal silicon mirrors with 39NiFe inserts for attachment, as well as single crystal silicon support structures to provide a system that is athermal. The telescope concept can scale up to meter class, as demonstrated for the SBL-IFX space based meter class laser. Single crystal silicon, a material that behaves isotropically; and McCarter processing methods are critical in providing 80-325 mm missile interceptor telescopes that will not blur, creep or jitter during thermal and/or mechanical loads. SCiSi is the only material that can handle endo- and exo-thermal missions. After two decades of prototyping and third party testing McCarter has created a TRL-6 solution to overcome single crystal silicon size and complexity restraints. These manufacturing processes are comprised of single crystal silicon; glass frit bonding and metal insert attachment. McCarter silicon mirrors are successfully fielded in ABL, THEL, MTHEL, CRAM200, INSS and others. After building EKV mirrors during MDA SBIR B044-095-1205, “define and demonstrate a beryllium substitute material for GMD applications”, McCarter was contracted by WSMR to replace their cooled molybdenum mirrors with single crystal silicon mirrors incorporating our processing technology. Molybdenum is a heritage material that, like beryllium, is in-efficient and extremely expensive. The use of McCarter’s modular approach enabled a compact HEL system without the need for any coolers. This contract for WSMR, as well as another with MZA, Albuquerque NM with modular single crystal silicon helicopter HEL mirrors raised the technical readiness level to 6. In addition to detecting and deterring hostile missiles this same technology will mitigate space trash and protect against asteroids of all sizes. 

Biography:

Morad Eghbal is currently a PhD student conducting research in Microwave Photonics under the supervision of Dr. Mehdi Shadaram at the Photonics Research Lab at The University of Texas at San Antonio. His research interests are photonic generation of millimeter waves and radio-over-fiber communications.

Abstract:

Introduction of services and applications that require higher bandwidth and augmented bitrates are dramatically increasing. Services such as live broadcasting and video streaming demands a larger bandwidth along with minimal latency and enhanced reliability. Thus, the mainstream of the future mobile communication is governed by how much bandwidth can be dedicated for such services and therefore how the capacity of the network can be improved to keep up with the growing demand for bandwidth. An effective method to increase the capacity of a network is to migrate to higher frequency bands. Millimeter-wave region has promising features that can accommodate higher capacities with working frequency in the 57-64 GHz (V-band) and 75-110 GHz (W-band) regions. Also, they offer enhanced security based on their narrow beam-width antenna and higher attenuation in the free space propagation making them only available across their designated coverage. Higher attenuation can be overcome by introduction of radio-over-fiber techniques in which millimeter-wave signal (radio frequency wave) can be transmitted through optical fiber to effectively increase the propagation distance compared to the free space propagation. Therefore, millimeter-wave radio over optical fiber can be an efficient method to transmit millimeter-wave signal to longer distances. In this paper, we propose a W-band optical code division multiplexing access (OCDMA) radio-over-fiber system generated by tandem dual electrode Mach Zehnder modulator (DE-MZM). To increase the capacity, we introduced the optical encoding and decoding with the help of superstructure fiber Bragg gratings (SSFBG). Also, to generate millimeter-wave signal, a tandem DE -MZM driven by signal generators operating at frequency range of less than 30 GHz have been used to decrease the overall cost and increase the stability of the system. The simulation results will be presented. The stability, capacity and reach of the system are improved while the cost and complexity are reduced.

Biography:

Sania Saleem is 22 years old. Is currently a student doing Masters of Science in Astronomy and Astrophysics from Institute of Space Technology, Islamabad. Completed Bachelors of Science in Physics from Comsats Institute of Information Technology .Interested in the field of laser physics and will prefer P.HD in the field of laser Physics. She has done project on Laser Induced Plasma Spectroscopy of commercially available Brass and is currently doing research work on Laser induced plasma spectroscopy of Nanomaterials and have submitted a research paper on Spectroscopic Analysis of Calcite and Dolomite Marble using Laser Induced Breakdown Spectroscopy.

Abstract:

Laser induced plasma spectroscopy is employed to study the effect of laser irradiance on the marble samples collected from North-West region of Pakistan and determine the elemental composition of these samples. A pulsed Q-switched Nd:YAG laser with fundamental and second harmonics in conjunction with the LIBS 2000 detection system were used to ablate the sample surface to produce the plasma and record the spectra of radiation emitted. The spectra show different elements including calcium, magnesium and sodium whereas lines emitted by Ca are dominating. The electron temperature of the plasma produced was determined by Boltzmann Plot Method and electron number density was determined from the broadening of spectral lines using Stark broadening. The plasma plume generated at the surface of the samples is studied by varying the laser energy from 15mJ to 40mj and distance along the plume length from the surface of the sample from 0.0mm to 1.0mm. It is observed that the electron temperature and number density are increased with increase of laser irradiance and decreased with the distance from the sample surface.

Biography:

Marco Ornigotti has completed his PhD in Physics from the Polytechnic Institute of Milan in Italy and has done his Post-doctoral studies at the Max Planck Institute for the Science of Light from 2010-2013 in the Optics Theory Group led by Dr. Aiello. Currently, he is pursuing his second Postdoctoral degree from the Friedrich Schiller University in Jena. He is a well-recognized scientist in the community of Optical Beams and the Angular Momentum of Light, with more than 20 publications in reputed international journals.    

Abstract:

Teleportation is the most widely discussed application of the basic principles of quantum mechanics. Fundamentally, this process describes the transmission of information, which involves transport of neither matter nor energy. The implicit assumption, however, is that this scheme is of inherently nonlocal nature, and therefore exclusive to quantum systems. Here, we show that the concept can be readily generalized beyond the quantum realm. We present an optical implementation of the teleportation protocol solely based on classical entanglement between spatial and modal degrees of freedom, entirely independent of non-locality. Our findings could enable novel methods for distributing information between different transmission channels and may provide the means to leverage the advantages of both quantum and classical systems to create a robust hybrid communication infrastructure.

Biography:

Chen Chen is a PhD candidate in Southeast University. Currently, she is working on the mechanism of intercellular communication between cancer derived exosomes and cells using single molecule localization based super resolution microscope.
 

Abstract:

Exosomes are cell-derived microvesicles presented in body fluids. The diameter of exosomes is around 30-100 nm. Exosomes play an important role in intercellular communications, exchanging of substances and diagnostic drug delivery. Recently, despite increasing scientific and clinical interest in exosomes, the moderate resolution of conventional optical microscopy limits the accurate localization and intracellular tracking of exosomes. Herein, we realize the application of single molecule localization based super resolution imaging technique (PALM/STORM) in the imaging and tracking of cancer derived exosomes. Firstly, successful extraction of cancer-derived exosomes from culture media are conducted and confirmed. Then labeling and imaging of exosomes membrane receptors are accomplished with photo-switchable probes. Moreover, simultaneous dual-color PALM imaging of the cancer derived exosomes is also presented. The most remarkable characteristic of this method is its excellent spatial resolution for exosomes observing at scales down to the nanometric level. Moreover, we demonstrate that cancer exosomes taken up by normal cells can be more precisely visualized through the presented PALM/STORM strategy. In addition, we also realize dual color PALM/STORM imaging of exosomes and lysosomes, which more vividly confirm the intracellular localization and accumulation of exosomes. The presented results indicate that PALM/STORM imaging is a powerful tool for the study of exosomes mediated cancer metastasis.

Biography:

Peng Chen is a PhD candidate in Advanced Photonic Center of Southeast University. He is now working on SERS and Fluorescence based Optical Biosensor.

Abstract:

Currently, stimuli-responsive nanocarrier for dual-drug delivery is considered as a promising approach for highly effective therapy in cancer treatment. However, intracellular monitoring of the dual-drug release is still challenging. Here, we fabricate a pH and thermo dual-stimuli-responsive dual-drug nanocarrier based on gold-silver core-shell nanoparticles (Au@AgNPs) functionalized carbon nanotubes (CNTs). By using label-free surface enhanced Raman scattering (SERS) and fluorescence techniques, we can monitor the dynamic process of drug release. In this nanocarrier a model drug indole is loaded inside the hollow tunnel of CNTs and released into cells by near-infrared (NIR) irradiation. Doxorubicin (DOX) is loaded on the surface of CNTs via π–π stacking and released by changing pH values. In the experiment, to investigate the intracellular traceable delivery performance of this nanocarrier, the dual-drug loaded nanocarrier was incubated with living HeLa cells. Experimental results indicated that the release of indole and DOX can be triggered by the photo-thermal effect and the acidic pH of lysosomes, respectively. Moreover, the combination of released indole and DOX exhibited significant cell-killing effects. The proposed functional CNTs act as an excellent near-infrared and pH-sensitive controllable delivery system for killing cells in application of cancer therapy.

Biography:

Mingjia Shangguan has received his BS degree from Jilin University of Architecture in 2012. He is pursuing his PhD in Hefei National Laboratory for Physical Sciences at the Microscale at University of Science and Technology of China. His current research interests include Upconversion Technique and its application in Optical Fiber Sensors. 

Abstract:

A direct-detection Brillouin optical time-domain reflectometry (BOTDR) using a photon-counting up-conversion detector (UCD) and an all-fiber structure Fabry–Perot scanning interferometer (FFP-SI) is demonstrated with shot-noise limited performance. In order to detect the weak spontaneous Brillouin backscatter signal efficiently, an ultra-low noise equivalent power of the photon-counting UPD is adopted, which up-converts the backscattering signal at 1548.1 nm to 863 nm, and then detected by a Si-APD. The final system efficiency of the UPD is 15% with a noise of 40 counts per second. By using high spectral resolution of the FFP-SI, the Brillouin spectra along a polarization maintain fiber (PMF) is analyzed in the optical frequency domain directly. In comparison with heterodyne BOTDR, direct-detection BOTDR has better EM compatibility and faster speed in data processing. In experiments, with peak input power of 20 dBm, temperature profile along a 9 km PMF is retrieved according to the Brillouin shift, with spatial/temporal resolution of 2 m/15 s. The precision is 0.7ºC at the leading end and 1.2ºC at the trailing end.

Biography:

Li Jian received a Bachelor of Science degree from Harbin Engineering University in 2011 with major in Optical Information Science and Technology. From 2011 to 2014, he has worked at Foxconn Technology Group as a Photoelectric Equipment Development Engineer. Since 2014, he has been studying Master’s in Optics from Harbin Engineering University. His research interests are fiber optics, fiber sensor and long-period fiber grating. He has published two papers in the Science Citation Index and presented at a conference of Society of Photo-Optical Instrumentation Engineers. He has been invited as a Speaker for the 5^th International Conference and Exhibition on Lasers, Optics and Photonics which will be held during November 28-30, 2016 in Atlanta, USA.

Abstract:

Long-period fiber grating (LPFGs) have attracted considerable attention recently for many applications in fiber sensors. The LPFGs can measure various physical parameters, such as, temperature, strain, refractive index and curvature. In our work, we provide a method to enhance the temperature sensitivity of LPFG. We propose a new type of LPFG, using the filament heating method for measurement of temperature. The LPFG is composed of many micro-tapers, which were fabricated using a GPX-3000 glass processing system (Vytran Corp). By using the Vytran Corp, the heating element was kept fixed and the translation stages with fiber clamps were moved in the same direction with different velocities. We can control the relative moving velocity of the translation stages and the power of heating filament to fabricate different geometric profiles micro-tapers. We used a vacuum coating machine (JS-1600). The thickness of gold thin film increased from 0 nm to 100 nm, and then increased to 200 nm. We tested the temperature sensitivities of the LPFG at three film thicknesses, respectively. The LPFG was placed in a temperature control chamber to test the temperature response. When the environmental temperature increased from 22 to 222ºC, the resonance wavelength had a red shift. The temperature sensitivity of the LPFG with no gold film is 48 pm/ºC. The temperature sensitivities of the 100 nm and 200 nm gold thin film-coated LPFGs are approximately 71 and 67 pm/ºC, respectively. We can enhance the temperature sensitivity of the LPFG by gold thin film-coated. The temperature sensitivity of the LPFG increases first and then decreases with the increase of gold film thickness, which is higher than the temperature sensitivity before coating.

Biography:

Vladislav E Bougrov is the Director of School of Photonics and Head of Chair of Light Technologies and Optoelectronics at the ITMO University, St. Petersburg, Russia. He has obtained his Master’s degree in Optoelectronics from Department of Optoelectronics, PhD in 1999 and DSc in Physics in 2013 from Ioffe Institute, St. Petersburg, Russia. He is the author of more than 60 papers in reputed journals, inventor in more than 100 patent applications, including more than 30 granted patents and has extensive experience with dynamic management of growing international start-up companies. He is the founder of Optogan.

Abstract:

Ever-growing demand for high-speed internet, optical interconnects in data centers; development of cloud technologies set a trend for moving communication technologies from electronics to photonics. Volumes of information transmitted in the last ten years increased by 50 times, continuing to grow at the same rate. 10% of all electric energy in the world is consumed by Internet, this demand doubles every four years. Combinations of optical and wireless communication technologies resulted in development of a new area of photonics – microwave photonics (MWP). Using MWP systems in hybrid fiber-radio system becomes crucial for reliable operation of next-generation intelligent optical network. To become a viable alternative for electronic components, photonic components must be fabricated in integrated-circuit form. Integration makes them reliable, compact, cost- and energy- effective, convenient for signal and inter-connect matching. III-V compound semiconductor materials are very promising for photonics integrated circuits (PIC) due to their ability to integrate both active and passive devices along with potential of offering cost effective mass production. Currently, PICs are essentially operating in analog mode. As a result, they accumulate the errors while cascading a number of devices. This results in severe degradation of signal quality and requires regeneration of signals. Electronic high speed analog-to-digital converters (ADC) are facing a limited effective number of bits at frequencies of more than 1 GHz due to timing jitter of electronic sampling clocks and ambiguity bottlenecks. To overcome the aperture jitter, it is crucial to perform sampling in the optical domain using low-jitter optical pulse trains generated by a mode-locked laser. We report on different layouts of photonic ADCs based on III-V semiconductor components. We report on modeling and fabrication of integrated 10 GHz III-V semiconductor components, such as monolithic mode-locked lasers, PIN photo-detectors based on InGaAs/InAlGaAs heterostructures, operating at wavelengths of 1520-1580 nm.

Biography:

Maria Tchernycheva is an Engineer from Ecole Polytechnique (X98). She has received PhD in Physics from the Université Paris Sud, Orsay (France) in 2005. In the year 2005, she joined the Laboratory for Photonics and Nanostructures, CNRS, Marcoussis, France as a Post-doctoral Researcher. Her work was focused on the fabrication of III-V and III-N semiconductor nanowires by molecular beam epitaxy. In 2006, she joined CNRS at the Institut d’Electronique Fondamentale of University Paris-Sud in Orsay where she is currently leading the “NanoPhotoNit” Research Group focusing on the fabrication and testing of novel optoelectronic devices based on semiconductor nanowires. She has published more than 100 articles in international journals, which gathered more than 2000 citations (her Hirsh index is 32). She received the Madeleine Lecoq award from the French Academy of Sciences in 2006.

Abstract:

“Photonics multiannual strategic roadmap 2014-2020” mentions flexible electronics, flexible light sources, displays and solar cells as key emerging technologies with high expected growth of the market share. Indeed, flexible devices offer new functionalities inaccessible with conventional technologies (e.g., rollable screens, bendable or implantable light sources, energy harvesters integrated in clothing, etc.) It is noteworthy that in the above-mentioned roadmap the notion of a flexible device is inseparable from an organic device. Technologies based on organic semiconductors have indeed made a huge progress in the past 10 years; however, organic devices still suffer from a short lifetime and low efficacy as compared to their inorganic counterparts. Taking an example of light emitting diodes (LEDs), organic LEDs suffer from strong degradation in the blue spectral range and their luminance at high current is low. Blue LEDs based on nitride semiconductors reveal high brightness and efficiency, yet conventional thin films represent rigid structures, which make fabrication of flexible devices rather difficult. In this context, nanowires offer an elegant solution to the problem. Single nanowires and nanowire array LEDs based on InGaN/GaN core/shell heterostructures have been successfully demonstrated on rigid substrates, showing excellent performances in the blue spectral range, thanks to their high crystalline quality and non-polar active region. I will present our recent work on nitride nanowire-based light emitters and photodetectors. These nanomaterials have the potential to boost the device performance, improve energy efficiency, reduce the cost, and bring new functionalities. In particular, I will discuss our recent progress towards flexible nitride nanowire devices: we propose a method to combine high flexibility of polymer films with high quantum efficiency provided by nitride nanowires to achieve flexible inorganic LEDs and light sensors.

Biography:

Roberto Morandotti has received his MSc in 1993 from the University of Genoa (Italy) and his PhD in 1999 from the University of Glasgow (UK). Since 2008, he is a Full Professor at Institute national de la recherche scientifique (INRS-EMT). Since 2015, he has been working as an Adjunct Professor at the University of Electronic Science and Technology of China (Chengdu‏, China) and is a Visiting Professor at ITMO (St. Petersburg, Russia). He is an E W R Steacie Memorial Fellow, a Fellow of the Royal Society of Canada, APS, OSA, IoP and SPIE, as well as the General Co-chair of CLEO QELS 2016.

Abstract:

Optical quantum states are fundamental for several applications ranging from sensing and secure communications to quantum computation. The generation of such quantum states on a compact integrated platform will allow for customizable, low-cost, and large-scale implementations, enabling accessible advances for quantum technologies. With current advances in optical quantum information processing (e.g. the realization of the first commercial quantum cryptography systems and computers), it is foreseeable that such reliable, low-cost and scalable on-chip sources of single and entangled photons will represent a key enabling technology for quantum applications. Therefore, the realization of integrated quantum sources has attracted considerable attention from the scientific community. However, major difficulties arise when sources need to satisfy several requirements at the same time, i.e. a narrow spectral bandwidth, high-purity single-mode generation, high production rates, stable long-term operation, multiplexed broadband operation, and high-quality entanglement shared between photons. We show that integrated quantum frequency comb sources can address these important requirements. We demonstrate the generation of pure heralded single photons, cross-polarized photon pairs, as well as entangled two- and multi-photon photon states, distributed over many frequency modes and spanning the complete fiber-optical telecommunications band. Integrated quantum frequency combs therefore provide a scalable and versatile platform for quantum information processing. 

Biography:

Karim D Mynbaev has received his MSc in Optical-Electronic Systems from St. Petersburg Electro-technical University “LETI” in 1986, and his PhD and DSci degrees in Semiconductor Physics from Ioffe Institute in 1992 and 2007, respectively. His research interests mostly concern narrow-bandgap semiconductors and optoelectronic devices designed to operate in the mid-infrared (2-6 µm wavelength range) part of the spectrum, based on II-VI (Hg,Cd)Te and III-V (InAs(Sb,P)) systems. He is also involved in the studies of defect structure of wide-bandgap materials, such as SiC and GaN. He has authored and co-authored more than 100 papers in international peer-reviewed scientific journals and 2 book chapters. Currently, he heads the Laboratory of Photoelectrical Phenomena in Semiconductors at Ioffe Institute, and serves as a Professor at the Chair of Light Technologies and Optoelectronics at ITMO University.

Abstract:

According to conventional wisdom, in regards to optoelectronics, III-V semiconductor materials prevail over their II-VI counterparts due to stronger chemical bonds and more advanced fabrication technology of the former. Ever increasing demand in various types of optical sensors, especially these operating in the infrared part of the spectrum, where they are employed for controlling environment and manufacturing processes, as well as in medical devices, strongly challenges current technology and requires more efficient light sources and photodetectors. In this talk, I will review recent progress in mid-infrared (2-6 µm wavelength range) optoelectronics in regards to competing III-V and II-VI materials and nanostructures. In particular, prospects of II-VI-based light emitters will be considered in view of the latest results achieved with the use of molecular beam epitaxy-grown (Hg and Cd) Te nanostructures, where engineering of compositional fluctuations in the alloy seems to advance the emitting properties of these well-known materials to a new level. Concerning III-V materials, I will consider the results of the latest experiments showing the effects of specific non-radiative recombination processes on the properties of narrow-bandgap light emitters, and discuss the prospects that proper optical confinement promises in terms of increasing the efficacy of such devices. Recent experimental findings will be compared to the results of specified calculations of recombination rates in the materials in question.

Biography:

Vladimir G Dubrovskii has received his BS and MS degrees from Saint Petersburg University, and PhD and DSc degrees from Ioffe Institute and Saint Petersburg University in 1986, 1988, 1990 and 2002, respectively, in Condensed Matter Physics. His research interest has been in the areas of condensed matter physics and semiconductor nanostructures. He has authored more than 450 papers in leading technical journals and conferences and 2 monographs. His current research interests are mainly concentrated on nanowire modeling as well as on nucleation theory with applications in physics of semiconductor nanostructures. He is the Head of the Laboratory of Physics of Nanostructures at St. Petersburg Academic University, Head of the International Laboratory “Physics of Epitaxial Nanostructures” at ITMO University and Leading Research Scientist at Ioffe Institute. He is a Member of Steering Committees of International Symposium “Nanostructures: Physics and Technology”, Nanowire Growth Workshop and iNOW Workshop. He is the recipient of a number of academic and university awards and has been a high-level Visiting Scientist at Beijing University of Posts and Telecommunications.

Abstract:

In this talk, I will review recent achievements in monolithic integration of optical III-V nanowires and nanowire-based heterostructures of different types [axial, radial, “quantum dot in nanowire” and crystal phase wurtzite-zincblende (WZ-ZB) heterostructures] on silicon surfaces. The vapor-liquid-solid (VLS) as well as catalyst-free bottom-up approaches to grow conventional III-V and GaN nanowires on silicon can pave new ways for integration of III-V-based optoelectronics with the existing silicon electronic platform. Due to their small dimensions in contact with the substrate and/or within hetero-interfaces, nanowires allow for a radical decrease of the dislocation density and even the dislocation-free growth of dissimilar semiconductor materials and combinations. In particular, I will show how Ga-catalyzed VLS growth of GaAs nanowires by molecular-beam epitaxy produces size and spatially uniform arrays of photonic nanostructures. I will discuss the optical heterostructures within III-V nanowires and their interfacial abruptness compared to planar layers and then will show some impressive results on the nanowire-based microlasers. I will also demonstrate that the comprehensive growth modeling helps to understand and tune very delicate nanowire properties to the desired values that are often unique and inaccessible within standard planar technologies.

Biography:

Vladimir G Dubrovskii has received his BS and MS degrees from Saint Petersburg University, and PhD and DSc degrees from Ioffe Institute and Saint Petersburg University in 1986, 1988, 1990 and 2002, respectively, in Condensed Matter Physics. His research interest has been in the areas of condensed matter physics and semiconductor nanostructures. He has authored more than 450 papers in leading technical journals and conferences and 2 monographs. His current research interests are mainly concentrated on nanowire modeling as well as on nucleation theory with applications in physics of semiconductor nanostructures. He is the Head of the Laboratory of Physics of Nanostructures at St. Petersburg Academic University, Head of the International Laboratory “Physics of Epitaxial Nanostructures” at ITMO University and Leading Research Scientist at Ioffe Institute. He is a Member of Steering Committees of International Symposium “Nanostructures: Physics and Technology”, Nanowire Growth Workshop and iNOW Workshop. He is the recipient of a number of academic and university awards and has been a high-level Visiting Scientist at Beijing University of Posts and Telecommunications.

Abstract:

In this talk, I will review recent achievements in monolithic integration of optical III-V nanowires and nanowire-based heterostructures of different types [axial, radial, “quantum dot in nanowire” and crystal phase wurtzite-zincblende (WZ-ZB) heterostructures] on silicon surfaces. The vapor-liquid-solid (VLS) as well as catalyst-free bottom-up approaches to grow conventional III-V and GaN nanowires on silicon can pave new ways for integration of III-V-based optoelectronics with the existing silicon electronic platform. Due to their small dimensions in contact with the substrate and/or within hetero-interfaces, nanowires allow for a radical decrease of the dislocation density and even the dislocation-free growth of dissimilar semiconductor materials and combinations. In particular, I will show how Ga-catalyzed VLS growth of GaAs nanowires by molecular-beam epitaxy produces size and spatially uniform arrays of photonic nanostructures. I will discuss the optical heterostructures within III-V nanowires and their interfacial abruptness compared to planar layers and then will show some impressive results on the nanowire-based microlasers. I will also demonstrate that the comprehensive growth modeling helps to understand and tune very delicate nanowire properties to the desired values that are often unique and inaccessible within standard planar technologies.

Biography:

Mara Duffles graduated in Physical Therapy from the University Salgado de Oliveira (2007) and a degree in Law from the Catholic University of Minas Gerais (1990). She has obtained Master’s in 2012. She took training in Acupuncture, Clinical Pharmacology and in traditional Chinese medicine, both with the title of specialist, Manual Therapy in Pathologies Craneocervical, Craneomandibular and Facial Pain by Rocabado Method and Manual Therapy by Busquet Physiological Chains Method as well as improvement in laser therapy Low intensity from the Federal University of Minas Mines.

Abstract:

Background: Adhesions commonly occur after abdominal surgery and can cause bowel obstruction, chronic abdominal pain and infertility. Their prevention remains a challenge.

Objectives: To evaluate the effects of the application of low-level lasers on the prevention of adhesions and scarring of the skin after peritoniectomia.

Method: 24 New Zealand breed male rabbits, approximately 2months of age, were randomly divided into 3 groups (n=8): GC—control group not subjected to laser, GL1—group with laser application at a dose of 0.2 J, and GL2—group with laser application at a dose of 3.6 J. All animals performed peritoniectomia. After 14 days postsurgery, the animals were killed and adhesion formation was evaluated qualitatively and quantitatively. Differences were considered significant at P<0.05.

Results: The adhesion formation was observed in100% of the rabbits from groups GC and GL1, as compared to 37.5% of the rabbits from group GL2 (P<0.01). The evaluation of the vascularization and tenacity of adhesions among the groups showed no significant difference. In groups CG and GL1, 72% and 83% of adhesions were verified between visceras, respectively where as in GL2 occurred among abdominal wall. The tensile strength of the skin between the groups was not significant (P=0.3106). The resistance of abdominal wall segments without skin segments between groups GL2 and GC were higher than in GL1 (P=0.01).

Conclusion: Low-level laser is effective in preventing intra-abdominal adhesions in rabbits without compromising strength and healing of the abdominal wall. 

Biography:

Won Bong Lim has completed his PhD from the Department of Oral Pathology and Post-doctoral studies from Chonnam National University in South Korea. He is an Assistant Professor in the Department of Premedical Science, College of Medicine, Chosun University and Director of Research Lab at Department of Orthopedic Surgery in Chosun University Hospital. He has published more than 50 papers in reputed journals of Low Intensity Laser Therapy and Cancer Biology. 

Abstract:

Low-level laser therapy (LLLT)/LED therapy has been proposed as an alternative to conventional osteoporosis therapies. Our aim was to determine the effect of irradiation with a light-emitting diode on receptor activator of NF-κB ligand (RANKL)-mediated differentiation of mouse bone marrow macrophages into osteoclasts, and compare it to alendronate treatment. The surface of cells was irradiated with LED at 5 mW/cm² for 60 minutes in a CO₂ incubator. The differentiation of irradiated and untreated RANKL-stimulated bone marrow macrophages into osteoclasts was evaluated by tartrate-resistant acid phosphatase (TRAP) staining and by molecular methods. These included assessing mRNA expression of osteoclastic markers such as c-Fos, NFATc1, TRAP, OSCAR, MMP9, and cathepsin K; phosphorylation of various MAPKs, including extracellular signal-regulated kinase ERK1/2, P38, and JNK; NF-κB translocation; and resorption pit formation. Results were compared to those obtained with sodium alendronate. Production of reactive oxygen species was measured by a 2ʹ,7ʹ-dihydrodichlorofluorescein diacetate assay. LED irradiation and alendronate inhibited mRNA expression of osteoclast-related genes, such as TRAP, c-Fos, and NFATc1, and reduced the osteoclast activity of RANKL-stimulated bone marrow macrophages. LED irradiation, but not alendronate, also inhibited the production of reactive oxygen species; phosphorylation of ERK, P38, and IκB; and NF-κB translocation. These findings suggest that LED irradiation has an inhibitory effect on osteoclast formation; this effect could lead to reduced bone loss and may offer a new therapeutic tool for managing osteoporosis.

Biography:

Haiyan Fu is an experienced Researcher in Analytical Techniques and Chemometric. She has completed her PhD from Hunan University. She is an Associated Professor and Director of the Department of Pharmaceutical Analysis at South Central University for Nationalities, China.

Abstract:

As a popular detection model, the fluorescence “turn-off” sensor based on quantum dots (QDs) has already been successfully employed in the detections of many materials, especially in the researches on the interactions between pesticides. However, the previous studies are mainly focused on simple single track or the comparison based on similar concentration of drugs. In this paper, a new detection method based on the fluorescence “turn-off” model with water-soluble ZnCdSe and CdSe QDs simultaneously as the fluorescent probes is established to detect various pesticides. The fluorescence of the two QDs can be quenched by different pesticides with varying degrees, which leads to the differences in positions and intensities of two peaks. By combining with chemometrics methods, all the pesticides can be qualitative and quantitative respectively even in real samples with the limit of detection was 2x10-8 molL^-1 and recognition rate of 100%. This work is, to the best of our knowledge, the first report on the detection of pesticides based on the fluorescence quenching phenomenon of double quantum dots combined with chemometrics methods. What’s more, the excellent selectivity of the system has been verified in different mediums such as mixed ion disruption, waste water, tea and water extraction liquid drugs. The results show that this fluorescent “turn-off” mode combined with chemometrics methods is a promising approach for the future study of the detection of pesticides residues.

Biography:

Peter A Bokhan received PhD and DSc degrees in Optics from Tomsk State University, Tomsk, Russia, in 1973 and 1988, respectively. He has been a Principal Scientist at the A V Rzhanov Institute of Semiconductor Physics, Siberian Branch Russian Academy of Science, Novosibirsk, Russia, since 1995. He is an author of more than 180 journal publications, 8 books and 20 patents. His current research interests include laser physics, gas discharge physics, methods of electron beam generation in gases and laser isotope separation.

Abstract:

It is desirable for the ultrafast communications, optical computer, etc., to create the lasing medium with as broad band as possible. To solve this task, the investigations of lasing and luminescence characteristics Si doped Al_xGa_1-xN epitaxial films 0.5…1.2 µm thickness on the sapphire substrate were carried out. The following excitation methods were used: а) by an electron beam with the energy to 20 keV, pulse duration 10 …100 ns; b) second harmonics and summary frequency of copper vapor laser on wave length 255, 271 and 293 nm; c) fourth harmonic of Nd³⁺:YAG laser with wave length 266 nm. In either case, the luminescence spectra are similar and they have an edge band with x-dependent wavelength from 365 nm to 310 nm and a broad band taking over the whole visible spectral range and near infrared one with broad band up to 500 THz. The main characteristics of superradiance in the broad band are presented. The spectral range depends from x and extends from 400 nm to 750 nm at x=0.5 and from 330 nm to 700 nm at x=1. The gain of active media also depends from x and is equal g=70cm^-1 for weak signal (0.7%/µm) for x=0.5 and g=20cm^-1 for x=0.74. The dependences of output power from active media length and pumping power demonstrate three features: a smooth growth at low pumping power or at small active length, then exponential growth and eventually comes to the saturation. The obtained resultants can be used for both the creation of waveguide lasers in a wide range and lasers with the femtosecond pulse duration. 

Biography:

Mahmoud Fallahi is a professor in the college of optical Sciences at the University of Arizona. He received his Ph.D. degree from the University of Toulouse and LAAS-CNRS, in 1988. He joined the National Research Council of Canada in 1989 and became a member of technical staff as a Research Scientist during 1992-1995. He joined the University of Arizona as an Assistant professor in 1995. His research has been extensively published in peer-reviewed scientific journals, reported in invited talks and published in international conference proceedings. He has authored or co-authored several book chapters, patents and invention disclosures. He has served as Conference Chair and Program Committee member in several international conferences in the field of semiconductor lasers and integrated optics. Since August 2014 he has been with the National Science Foundation (NSF) as a Program Director of the photonics program in the ECCS Division of Engineering Directorate. As a Program Director he is promoting and managing translational research in the field of optics and photonics.

Abstract:

High power, tunable two color semiconductor lasers are highly suitable for the new wavelengths generation thanks to various nonlinear conversions. Vertical external cavity surface emitting lasers (VECSELs) are of special interest due to the access to the high intracavity circulating power and wavelength control. In this talk, we will present our recently developed and patented T-cavity VECSEL capable of delivering high power, tunable two color emission will be presented. The T-cavity two-chip VECSEL allows emission of orthogonally polarized high-power collinear outputs of the two wavelengths. By composition and thickness engineering of strain-compensated multi-quantum well InGaAs active layers, a wide range of wavelengths is achieved. Intracavity birefringent filters are then used to facilitate tunability and wavelength separation between two colors. The tunability of the individual VECSEL chips in the collinear two-color T-cavity configuration enables the control of the spectral separation of the lasing peaks. A folded-cavity configuration of such laser is used for high power intracavity second harmonic and sum frequency generation of multi-watt blue and green emissions. Latest results will be reported. 

Biography:

Yanbo Bai has completed his PhD from Northwestern University. His research at Northwestern led to the most efficient and most powerful Quantum Cascade Lasers. His current role at Coherent is to develop more efficient 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. He also serves as reviewer for many journals.

Abstract:

Optically pumped semiconductor (OPS) laser has unique advantages over its electrically pumped counterparts. The most prominent one being power scalable without sacrificing the beam quality. Lasing in the fundamental frequency at near infrared with over 100 watts has been demonstrated. Visible power in tens of watts by second harmonic generation and ultraviolet power in several watts by third harmonic generation have been commercialized. In this work, an OPS gain model is developed based on the 8-band kp method. Theoretical and experimental result indicates that this model cans predict the threshold accurately. Temperature dependent simulation allows for the modeling of self-heating and thermal rollover, therefore predicting the achievable output power. Guided by this model, improvement of existing wavelength and expansion of the wavelength coverage are demonstrated.

Biography:

Sigang Yang has received his PhD degree from the Department of Electronics Engineering, Tsinghua University in 2008. He was a Post-doctoral Fellow in the Department of Electrical and Electronic Engineering in the University of Hong Kong. He has joined the faculty of Tsinghua University in August of 2010. He is now an Associate Professor in the Department of Electronic Engineering, Tsinghua University. His research fields include computational electromagnetism, photonic crystal fibers; fiber nonlinearities; fiber based optical parametric amplifications (FOPAs) and oscillators (FOPOs); terahertz wave and frequency comb. 

Abstract:

Light sources operating in the non-conventional wavelength band in which traditional lasers cannot oscillate have attracted great attention recently, since the applications of lasers are extending increasingly into new fields, such as biomedical imaging, spectroscopy and so on. Optical parametric generation in optical fibers refers to a phenomenon where weak spontaneous emission is amplified by the pump wave based on the effect of degenerate four-wave mixing (FWM). It can provide tunable radiation in non-conventional wavelength bands with the advantages of flexibility, low cost and compactness. The gain from parametric process depends on the phase matching condition among the pump, signal and idlers. And the dispersion profile of the gain fiber play a critical role in the phase matching mechanism. Photonic crystal fibers (PCFs) can provide more freedoms to customize its dispersion and nonlinearity, compared with the traditional fibers with doping technology. Especially its zero dispersion wavelengths can be located in nearly any wavelength and it has very large nonlinear coefficient. Thus, the parametric process in PCFs can provide gain in nearly any wavelength band according to the pump wavelength and the dispersion of PCF. Firstly, parametric wavelength conversion with very large span between visible and infrared band is demonstrated based on our homemade PCFs with two zero dispersion wavelengths. The theoretical design guideline is also introduced. Secondly, optical parametric amplifiers and oscillators based on PCFs pumped with 1060 nm band laser pulse are introduced in details. These works show that the optical parametric generation in PCFs is promising to provide light radiation in non-conventional wavelength bands.

Biography:

Peter A Bokhan received PhD and DSc degrees in Optics from Tomsk State University, Tomsk, Russia, in 1973 and 1988, respectively. He has been a Principal Scientist at the A V Rzhanov Institute of Semiconductor Physics, Siberian Branch Russian Academy of Science, Novosibirsk, Russia, since 1995. He is an author of more than 180 journal publications, 8 books and 20 patents. His current research interests include laser physics, gas discharge physics, methods of electron beam generation in gases and laser isotope separation.

Abstract:

The output characteristics of laser essentially depend on power supply pulse duration and its energy. This case is a very important switching characteristic of a device used for short and powerful pulse generation. The subnanosecond breakdown stage in the kivotron, novel switching device with counter-propagating electron beams based on the open discharge in helium, was experimentally studied. It was shown that the fast discharge stage arises when the discharge self-sustaining regime is ensured by the photoelectron emission from the cathodes due to resonant radiation emitted by fast helium atoms that have large Doppler shifts with respect to the line center. Since the excitation cross-section of a helium atom by another fast helium atom increases rapidly with the energy of the fast atom, the duration of the breakdown stage strongly depends on the working voltage in the range 2-10kV and weakly from 15 to 100 kV. The switching time less than 80ps was achieved when discharge circuit loaded to a resistance R_L≥50 Ω. Decrease of R_L down to 10 Ω increases the switching time to about 100ps at 1.5-kA current with current density 120A/cm². A minimum switching time that can be achieved via kivotron design optimization is estimated to be about 35ps. A kivotron has to be used for pumping of different laser, including copper vapor laser, semiconductor lasers, etc. It was demonstrated that in this case it is possible to improve essential laser output characteristics.

Biography:

Luis Gustavo Marcassa has completed his PhD from University of São Paulo and Post-doctoral studies from MIT. He is a Professor at the University of São Paulo. He has published more than 105 papers in reputed journals and has been serving as an Editorial Board Member of Journal of Physics B.

Abstract:

In recent years, there has been an increasing interest of early detection of citrus diseases to prevent great economic losses due contamination of new plants. There are two major citrus diseases: Citrus canker (Xanthomonas axonopodis pv. citri) and Huanglongbing (HLB, Candidatus Liberibacter asiaticus). Both are a serious threat to citrus production worldwide including regions in Brazil and USA. The whole process to confirm the diseases is time consuming and expensive. So, there is a demand for a fast, sensible, and selective method for the rapid detection of citrus diseases. One of these techniques, fluorescence spectroscopy has been investigated as a tool in plant studies, because it has the potential to discriminate different diseases in citrus crops and besides it is nondestructive and nonintrusive to the plant physiology. In the last decade, our group has applied laser induced fluorescence spectroscopy and fluorescence imaging spectroscopy to discriminate diseased samples with similar visual symptoms. Different computational methods were successfully used for the different citrus disease classification. In this work, we will present a review in our work on detection and classification of infected trees with citrus canker, citrus scab, HLB and zinc deficiency. Our recent results show that we obtain a high accuracy when compared either samples with citrus canker and citrus scab (100%), or samples with HLB and zinc deficiency (95%). Furthermore, the sensitivity and specificity obtained for each group is also high. Therefore, we believe that such technique can be applied in the field to detect diseases that have similar symptoms.

Biography:

Milo W Hyde IV received his BS degree in Computer Engineering from the Georgia Institute of Technology, Atlanta, GA, in 2001, and the MS and PhD degrees in Electrical Engineering from the Air Force Institute of Technology, Dayton, OH, in 2006 and 2010, respectively. He is currently an Associate Professor with the Department of Electrical and Computer Engineering, Air Force Institute of Technology. His current research interests include electromagnetic material characterization, guided-wave theory, scattering, and optics. He is a Senior Member of IEEE and a member of SPIE and OSA.

Abstract:

Existing in a state between coherent (e.g., lasers) and incoherent (e.g., incandescent) light sources, partially-coherent beams (PCBs) can be highly directional like a laser while also being resistant to scintillation or speckle. These characteristics make these beams attractive for use in applications such as free-space optical communications, directed energy, manufacturing, particle manipulation, medicine, and video projection. Considering their many potential uses, the study and especially synthesis of PCBs has become a very popular research subject. One of the most interesting developments to arise out of this work is the ability to precisely control beam shape by manipulating spatial coherence. The Air Force Institute of Technology working with New Mexico State University has been heavily involved in this research. We have developed several novel techniques to synthesize PCBs which yield beams of any desired shape. This presentation reviews this recent work in beam shaping using spatial coherence and discusses future research.

Biography:

Milo W Hyde IV received his BS degree in Computer Engineering from the Georgia Institute of Technology, Atlanta, GA, in 2001, and the MS and PhD degrees in Electrical Engineering from the Air Force Institute of Technology, Dayton, OH, in 2006 and 2010, respectively. He is currently an Associate Professor with the Department of Electrical and Computer Engineering, Air Force Institute of Technology. His current research interests include electromagnetic material characterization, guided-wave theory, scattering, and optics. He is a Senior Member of IEEE and a member of SPIE and OSA.

Abstract:

Existing in a state between coherent (e.g., lasers) and incoherent (e.g., incandescent) light sources, partially-coherent beams (PCBs) can be highly directional like a laser while also being resistant to scintillation or speckle. These characteristics make these beams attractive for use in applications such as free-space optical communications, directed energy, manufacturing, particle manipulation, medicine, and video projection. Considering their many potential uses, the study and especially synthesis of PCBs has become a very popular research subject. One of the most interesting developments to arise out of this work is the ability to precisely control beam shape by manipulating spatial coherence. The Air Force Institute of Technology working with New Mexico State University has been heavily involved in this research. We have developed several novel techniques to synthesize PCBs which yield beams of any desired shape. This presentation reviews this recent work in beam shaping using spatial coherence and discusses future research.

Biography:

Masayoshi Tonouchi has received the BS and MS and Dr. E degrees form Osaka University, Japan. He has worked at Osaka University, Kyushu Institute of Technology, Communications Research Laboratory. Currently, he is a Professor in Institute of Laser Engineering, Osaka University and a concurrent Professor of Nanjing University. He has published more than 250 papers, given over 100 invited talks and has been serving as an Associated Editor, Journal of Applied Physics, an international organization Committee Member of IRMMW, and Editorial Board Member of many journals. He chaired many international conferences such as OTST2013.
 

Abstract:

One can observe terahertz (THz) radiation from various kinds of materials, when excited with a femtosecond laser, owing to ultrafast current modulation. THz waves reflect various kinds of properties such as local electric field, particularly ultrafast transient phenomena, in their waveforms. The observation of the THz waveforms enables us to explore ultrafast nature of electronic materials and devices as a THz emission spectroscopy. When one excites the THz emission from a certain substance with the femtosecond optical pulses and visualizes the emission image by scanning the laser beam on it, the resolution of the image is limited by the laser beam diameter rather than THz wavelength. Thus, construction of a laser-THz emission microscope (LTEM) would provide a new tool for material/device science and application. We proposed and have been developing LTEM since 1997. In this talk, we will report the basics of LTEM, and applications for evaluation of solar cells and GaN wafers. 

Biography:

Zhe Wang has his expertise in Laser Diagnostics especially in LIBS. He has completed his PhD from the Pennsylvania State University. He is Associated Professor and Executive Director of the Institute of Simulation and Control for Power System and has been working on Coal Analysis using LIBS for years. 

Abstract:

Laser-induced breakdown spectroscopy (LIBS) has shown great potential in coal analysis, steel analysis, environmental monitoring, etc. Recently, the LIBS community of China has been great expanded and progress has been made to this technology. Low sample-to-sample repeatability of LIBS is the most critical obstacle for accurate quantification and wild commercialization of the technology. In this work, we proposed a set of method to improve both precision (sample-to-sample reproducibility) and accuracy for LIBS quantification. The method includes three steps: 1) the intensities of all spectral lines from every single pulse are converted to a standard state value using a “spectrum standardization” method to reduce the measurement uncertainties to some acceptable levels; 2) the standardized spectra are compared with a large spectral database for identification to check whether the current measured sample is a new sample or has already been in the database with known composition/property information; 3) if the sample is found to be a new sample, a dominant factor based partial least square (PLS) model will be applied to provide quantitative analytical results and the new standardized spectral information and analytic results are inserted into the spectrum database, making the database self-adaptable for future measurement; while if the sample is found to be already in the database, the analytic result will be directly obtained from the database. The proposed method was applied for coal analysis. Results showed that the relative standard deviations (RSD) of carbon for different measurements of the same sample were 0.3%, proving that LIBS is able to provide high reproducibility at least for coal analysis applications. This is the first qualified quantitative application for LIBS with real industrial requirement and the present work has proved the feasibility of LIBS for accurate quantification from technical point of view. The model was also applied for steel elemental analyses using portable LIBS, cement raw material online measurement, and origin identification for jade, with very qualified result for these applications.

Biography:

Jinbo Liu has completed his Doctor degree from Harbin Institute of Technology in 2009 and then worked in the Key Laboratory of Chemical Laser, Dalian Institute of Chemical Physics- CAS. Currently, he is an Associate Professor/Master Director of Chemical Physics.
 

Abstract:

High efficient generation of IR beam by SRS of high pressure H₂, D₂ and CH₄: Stimulated Raman scattering (SRS) is a very effective method to expand the spectrum range of high power laser, especially in the regime of near IR and middle IR. In this paper, SRS of high pressure H₂, D₂ and CH₄ with multiple-pass cell configuration were reported. By the optimization of experimental parameter, such as the pressure of Raman gas and buffer gas, the number of passes, the radium of focus lens, and the radium of curvature mirror, etc., the best conversion efficiency of the first stokes (S1) and the first stokes (S2) was achieved. The lowest S1 threshold was 0.18 MW, and the best S1 conversion efficiency is up to 75%; the lowest S2 threshold was 2.2 MW, and the best S2 conversion efficiency is up to 34%. By the combination of Raman gases and orders of stokes, lasers with wavelength of 1.54μm, 1.56 μm, 1.91 μm, 2.80 μm and 2.92 μm were generated. Experimental results also indicated that lasers with wavelength of 9.8 μm and 22.9 μm were generated.

Biography:

Jinbo Liu has completed his Doctor degree from Harbin Institute of Technology in 2009 and then worked in the Key Laboratory of Chemical Laser, Dalian Institute of Chemical Physics- CAS. Currently, he is an Associate Professor/Master Director of Chemical Physics.
 

Abstract:

High efficient generation of IR beam by SRS of high pressure H₂, D₂ and CH₄: Stimulated Raman scattering (SRS) is a very effective method to expand the spectrum range of high power laser, especially in the regime of near IR and middle IR. In this paper, SRS of high pressure H₂, D₂ and CH₄ with multiple-pass cell configuration were reported. By the optimization of experimental parameter, such as the pressure of Raman gas and buffer gas, the number of passes, the radium of focus lens, and the radium of curvature mirror, etc., the best conversion efficiency of the first stokes (S1) and the first stokes (S2) was achieved. The lowest S1 threshold was 0.18 MW, and the best S1 conversion efficiency is up to 75%; the lowest S2 threshold was 2.2 MW, and the best S2 conversion efficiency is up to 34%. By the combination of Raman gases and orders of stokes, lasers with wavelength of 1.54μm, 1.56 μm, 1.91 μm, 2.80 μm and 2.92 μm were generated. Experimental results also indicated that lasers with wavelength of 9.8 μm and 22.9 μm were generated.

Biography:

Gentaro Watanabe has completed his PhD from the University of Tokyo and Post-doctoral studies from NORDITA, University of Trento, and RIKEN. He has worked at APCTP as a Junior Research Group Leader/Assistant Professor and at the Institute for Basic Science in Korea, he is currently a ZJU Young Professor in the Department of Physics of Zhejiang University.

Abstract:

Interplay between the non-linearity due to the emergence of the superfluid order parameter and the effect of a periodic potential is one of the most important issues of ultracold atomic gases in an optical lattice. However, the study of non-linear phenomena of superfluid Fermi gases in an optical lattice is at a very infant stage unlike that for Bose gases. Appearance of stationary states whose period is not equal to the lattice constant but is a multiple of it, i.e., multiple period states, is a typical non-linear phenomenon. In this talk, we will discuss multiple period states of superfluid Fermi gases in an optical lattice along the crossover between the Bardeen-Cooper-Schrieffer (BCS) and Bose-Einstein condensate (BEC) states, which we have found recently. By solving Bogoliubov–de Gennes equations for a superfluid flow with finite quasimomentum, we find that, in the BCS side of the crossover, the multiple period states can be energetically favorable compared to the normal Bloch states and their survival time against dynamical instability drastically increases, suggesting that these states can be accessible in current experiments, in sharp contrast to the situation in BECs.

Biography:

Binayak S Choudhury is a Professor of Mathematics, Indian Institute of Engineering Science and Technology, Shibpur, West Bengal, India. He obtained his PhD degree in Applied Mathematics from University of Calcutta in 1995. He has published about 200 research papers in Mathematics and Physics. He has guided 14 PhD students. His areas of research interest include Functional Analysis, Quantum Information Theory and Cosmology.

Abstract:

It has been established through research activities over the last three decades that it is possible to make communications using quantum mechanical resources. A pioneering quantum communication protocol appeared in the work of Bennet et. al in 1993  which is known as quantum teleportation protocol. It is a process for transferring information through entangled channels. The work was followed by a large number of research works focusing on the extension of the process as well as for inventing protocols of similar types for performing various jobs of information and state transfer. There have been experimental realizations of some of these protocols. At the heart of these process lies the idea of quantum entanglement. The idea of entanglement can be traced back to the works of Einstein, Podolsky and Rosen in 1935. Its potential applications have been discovered during last two decades. There are various types of entanglements between two or more parties who, in the contexts of quantum communication, are the senders, receivers and possible controllers of the process. Here we present some  teleportation protocols where the purpose is to transmit multiqubit entangled states. We present the use of quantum channels which are robust in the noisy environment. Noise is a  serious concern for all communication systems. This can create devastation in the communication process. For that purpose we present the use of concatenated channels which are more stable against noise. Our protocols are perfect teleportation protocols, that is, there are no cases of failures.

Biography:

Jun Hee Choi received his PhD in Materials Science and Engineering from Seoul National University in 2012. He is currently a Research Master and Research Staff Member of the Device and System Research Center at Samsung Advanced Institute of Technology, Samsung Electronics. He has published more than 45 papers in SCI journals, more than 20 conference papers, and more than 50 US patents. His research includes GaN-based optoelectronics on unconventional substrates, and low dimensional electronics based on quantum dots, ZnO nanorods, and graphene.

Abstract:

There have been significant recent developments in the growth of single crystal gallium nitride (GaN) on unconventional templates for large-area blue or green light-emitting diodes (LEDs) which, together with layer transfer onto foreign substrates, can enable flexible and stretchable lighting applications. Here, the heteroepitaxial growth of GaN on amorphous and single-crystal substrates employing various interlayers and nucleation layers is discussed, as well as the use of weak interfaces for layer-transfer onto foreign substrates. Recent progress in low-temperature GaN-based red–green–blue (RGB) LEDs on glass substrates is discussed. Layer-transfer techniques with various interlayers are also discussed. These heteroepitaxial GaN growth and layer-transfer technologies are expected to lead to new lighting and display devices with high efficiency and full-color tunability, which are suitable for large-area, stretchable display and lighting applications. We shall also discuss blue light enhancement in CdS/ZnS quantum dots using surface plasmon resonance to achieve near-unity quantum yield.

Biography:

Ishwara Bhat has received his PhD degree in Electrical Engineering from Rensselaer Polytechnic Institute in 1985 and has joined the Department as a Research Assistant Professor in 1988 and tenure tract Associate Professor in 1991. Since 1999, he has been a Full Professor. His research interests include narrow gap materials such as HgCdTe, InGaSb as well as high band gap materials such as SiC and hBN. He has over 30 years of experience working in II-VI, III-V and IV-IV compounds, and has demonstrated several growth and device innovations.  He has published over 150 refereed journal articles and presented in over 100 conferences, both contributed and invited over the last 30 years.

Abstract:

Hexagonal boron nitride (hBN) is a wide bandgap semiconductor (Eg~6eV) with sp2-hybridized atomic sheets of boron and nitrogen. This material has attracted much attention for its properties such as high resistivity, high thermal conductivity (2000 Wm-1K-1), and stability in aggressive chemical environments and at high temperatures (up to 1000ºC). hBN, an insulating isomorph of graphene, has a small (1.7%) lattice mismatch to graphene and is expected to be atomically smooth and free from dangling bonds because of its sp2-hybridized bonding and weak interplanar Van der Waals bond. Hence, hBN is an excellent candidate to be used as a supporting substrate and gate dielectric for graphene based electronics. hBN is also an emerging material for deep UV photonics and for solid state thermal neutron detector application, since 10B, a constituent element of hBN, has a large thermal neutron capture cross section (3840 barns). This talk will present the recent results on the growth and characterization of thick (>12 μm) hexagonal boron nitride (hBN) and its use for deep UV detection and for solid-state thermal neutron detection. The hBN epilayers were grown by metalorganic chemical vapor deposition on sapphire and silicon substrates at a temperature of 1350ºC. A thin and amorphous nitride layer was formed at a low temperature (850ºC) on sapphire substrates, which enabled subsequent epitaxial hBN growth at 1350ºC. The influences of the sapphire nitridation temperature and the growth temperature on the film quality were analyzed by X-ray diffraction (XRD) measurements and UV response. X-ray diffraction peak from the (002) hBN plane at a 2θ angle of 26.7º exhibited the c-lattice constant of 6.66 Å for these films. A strong peak corresponding to the high frequency Raman active mode of hBN was found for the films at 1370.5 cm^-1. X-ray photoelectron spectroscopy analysis confirmed the formation of stoichiometric hBN films with excellent uniformity. On silicon substrate, it was necessary to deposit first a thin film of boron to prevent silicon nitride formation and degradation of the film quality. Thickness up to 15 microns have been grown and characterized. These results will be presented at the talk. 

Biography:

Seth Bank has received his BS from University of Illinois at Urbana–Champaign. He has done his MS and PhD degrees from Stanford University. After a Post-doctorate at UCSB, he joined the University of Texas at Austin, where he is currently an Associate Professor of ECE and holds a Temple Foundation Endowed Faculty Fellowship. His research focuses on the growth and application of novel heterostructures and nanocomposites to electronic/photonic devices. He has co-authored over 200 papers and presentations and has received PECASE, NSF CAREER, AFOSR YIP, ONR YIP, DARPA YFA, Young Scientist Award from ISCS, Young Investigator Award from NAMBE, and several best paper awards.

Abstract:

The application of Al_xIn_1-xAs_ySb_1-y to near- and mid-infrared optoelectronic devices has been hampered by the challenge of realizing high quality films, due to the wide miscibility gap. However, it was recently shown that AlInAsSb can be grown within the miscibility gap over a moderate range of compositions by molecular beam epitaxy using the digital alloy technique. We have extended this approach to realize AlInAsSb digital alloys covering the entire direct bandgap range that is lattice-matched to GaSb (Al fractions ranging from 0% to ~80%). The broadly-tunable bandgap (0.24 eV at 0% Al to 1.23 eV at 76% Al), along with the type-I band alignments of this lattice-matched quaternary make it attractive for advanced mid-infrared and near-infrared detectors and sources. For avalanche photodetectors in particular, these materials exhibit low excess noise characteristics – comparable to that of silicon and their band engineering flexibility proved indispensable for demonstrating the first low-noise separate absorption charge and multiplication (SACM) avalanche detector operating at telecom wavelengths and the first working staircase avalanche photodetectors. Here, we describe the growth and electrical/structural properties of these enabling materials. 

Biography:

Amur Margaryan has completed his PhD from Yerevan Physics Institute and continued studies in the field of Experimental Nuclear Physics at Yerevan Physics Institute; Serpukhov proton accelerator, Serpukhov, Moscow region; JLab, Newport News, VA, USA; MAX-lab, Lund, Sweden; and GRAAL experiment at European Synchrotron Radiation Facility in Grenoble, France. He is the Leading Scientific Researcher at A I Alikhanyan National Science Laboratory (Yerevan Physics Institute). He has published more than 150 papers in reputed journals. His current research interest is in Ultrafast Photon Detectors and Optoelectronic Devices. 

Abstract:

The radio frequency photomultiplier tube (RFPMT) combines the picosecond timing resolution of a streak camera with the fast readout of a photomultiplier. It is an entirely new device, currently under development at Yerevan and Glasgow in collaboration with Photek Limited (UK). Combination of the RFPMT with the optical frequency comb results in a high resolution (1 ps), high rate (≥ 1 MHz) and highly stable (10 fs/hr) timing technique for single photons. Such a device potentially has a large range of applications in fields ranging from physics to biomedical imaging. The principles of operation of the RFPMT will be described and possible applications to ultra-precise measurements in Physics and to ultra-high resolution optical microscopy will be outlined.

Biography:

Min Jae Ko is a Principal Research Scientist at Korea Institute of Science and Technology (KIST) and an KU-KIST Professor at Korea University. He obtained his BS (1995) and MS (1997) degrees from the Department of Fiber and Polymer Science and PhD (2001) from the Department of Materials Science and Engineering at Soul National University, Korea. He performed his Post-doc work at MIT from 2001 to 2004. Then he moved to Samsung Electronics Co., as a Senior Research Engineer in 2005. His research is focusing on the developments of materials and devices for the next generation flexible solar cells.

Abstract:

There have been significant progresses in the dye-sensitized (DSSCs) and perovskite solar cells (PSCs). Further cost reduction in high-speed manufacturing can be accomplished by continuous roll-to-roll printing processes using a flexible plastic substrate. Lightweight and flexible plastic solar cells can be installed even on non-flat surface, which makes them a possible ubiquitous power source for mobile electronics. The conventional TiO₂ photo-electrodes of DSSCs and PSCs are prepaed via a high-temperature sintering at 500 °C after deposition of the TiO₂ paste on fluorine-doped tin oxide (FTO) glass. However, the plastic substrates cannot withstand a sintering process at a temperature above 150 °C. This sintering process is essential since tight TiO₂ inter-particle connections are required for better performance, resulting in the reduction of internal resistance and fast electron transport. Various low-temperature processes have been demonstrated such as chemical sintering, mechanical pressing, hydrothermal crystallization, electrophoretic deposition, microwave irradiation, ultraviolet (UV) light irradiation, near infrared (NIR) oven, and film transfer. However, most of these methods contain quite complicated multi-step processes, not proper for the rapid production of DSSCs and PSCs using the R2R process. We have developed several facile methods for the fabrication of efficient flexible solar cells on plastic substrates by using assisted sintering process. In this talk, several strategies to address these issues will be introduced. 

Biography:

Shiva Kumar has completed his PhD degree (1997) from Osaka University, Japan. He has worked as a Post-doctoral Fellow at University of Jena, Germany, supported by Alexander von Humboldt Foundation from 1997-98. He has worked at Corning Incorporated, NY as a Senior Research Scientist (1998-2001). Currently, he is a Professor at McMaster University, Canada. He has published about 72 papers in many journals, authored a book on Fiber Optics, 7 book chapters, edited a book on Non-linear Fiber Optics, and holds 8 US patents.

Abstract:

An optical back propagation (OBP) technique is investigated to compensate for nonlinear impairments in point-to-point fiber optic communication systems as well as in networks with reconfigurable optical add-drop multiplexers (ROADMs). An OBP module consisting of an optical phase conjugator (OPC), amplifiers and dispersion-decreasing fibers (DDFs) fully compensates for the dispersion and nonlinear impairments of a transmission fiber. The dispersion profile of the DDF is calculated analytically by demanding that the OBP module compensates fully the nonlinear impairments due to the transmission fiber. The OBP module can be placed after each transmission fiber (inline OBP case) or at each network node (node OBP case). Although the digital back propagation can compensate for inter-channel nonlinear impairments in point-to-point systems, it would be impossible to mitigate these effects in digital domain in fiber optic networks since the channel path information is not available to the receiver. In contrast, OBP can compensate for inter-channel nonlinear effects in optical networks. Our simulation result shows that the OBP brings a significant performance advantage as compared to digital back propagation techniques in optical networks. In our simulations, non-ideal effects of the OBP module such as dispersion fluctuations of DDF, laser phase noise and relative intensity noise (RIN) of the laser used in OPC are included. We found that the node OBP outperforms the inline OBP since the noise introduced by the OPC in the case of inline OBP leads to performance degradations.

Biography:

Avner Peleg has received his PhD degree in Physics in 2001 from the Hebrew University of Jerusalem. He was a Post-doctoral Research Associate at Los Alamos National Laboratory and at the University of Arizona. He was an Assistant Professor at the University at Buffalo. He has published more than 30 papers in scientific journals and has been serving as an Editorial Board Member of the Heliyon journal. 

Abstract:

Raman crosstalk is one of the major impairments in massive wavelength-division-multiplexing (WDM) optical fiber communication systems and an obstacle for achieving scalability in WDM fiber optics networks. In this work, we present a theoretical method for mitigation of Raman crosstalk by employing frequency dependent amplification, such that high-frequency communication channels are over-amplified, while low-frequency communication channels are under-amplified compared with mid-frequency channels. Our method is based on showing that the dynamics of optical pulse amplitudes in an N-channel transmission system can be approximately described by a relatively simple predator-prey model for N species. Numerical simulations with the full propagation model, consisting of a system of N coupled nonlinear Schrödinger equations, show stable long-distance propagation of the optical pulses in good agreement with the predictions of the simplified predator-prey model. Moreover, we theoretically demonstrated that transmission stability can be further enhanced in nonlinear waveguide couplers due to efficient mitigation of radiative sideband generation by the frequency dependent linear gain and loss. 

Biography:

A Seteikin has studied Physics at the Pedagogical University in Blagoveshchensk. He has received his PhD in Physics in 2000. Currently, he is a Professor in the Department of Physics at the Amur State University in Blagoveshchensk. His scientific background is in the field of Laser - Tissue Interaction and Biophysics. In his work, he uses experimental and computational techniques. He has national and international collaborations in Physical and Life Science research.

Abstract:

The quantitative analysis of Raman spectroscopic signals in biological tissue is generally difficult. Typical samples contain a multitude of molecular species and, in addition, measurements altered by attenuation of the Raman signal. Realistic numerical modeling of the Raman process can help to facilitate the quantitative analysis of the Raman spectra, but approaches so far are scarce and often time-consuming. In this work, we report on two different and very efficient approaches for modeling of Raman scattering in turbid media irradiated by laser light. Both approaches utilize the Monte Carlo method to simulate the Raman scattering process. We compare the efficiency of both approaches and discuss possible future extensions and experimental validation. Most of simulations of Raman scattering use a two-step model, calculating the distribution of the incident radiation first and then re-launching Raman scattered photons based on this distribution. The reason for this approach is the fact that Raman scattering is a very weak process. Raman cross sections expected to be 10 orders of magnitude smaller than the quantum yields of fluorescence. The number of Raman photons or the weight of the Raman photon packages is extremely low after the Raman scattering event. The goal of this work is to provide a comparative evaluation of the two approaches for weaker processes such as conventional or resonance Raman scattering. In order to decide which model to use for a particular Raman application (normal, resonance, surface-enhanced, etc.), it is important to understand how these assumptions affect the numerical results obtained from the simulation.

Biography:

A M Polubotko has graduated from Physical Faculty of Leningrad State University in 1973. He has completed his PhD from Ioffe Institute, Russian Academy of Sciences and has been associated with the Azerbaijan Institute of Physics in Baku in 1983. Now he works as a Physicist Theorist and a Senior Scientific Researcher of Semiconductors and Dielectrics in the Department of Dielectrics and Semiconductors at Ioffe Physico-Technical Institute in Saint Petersburg. He has more than 120 scientific papers, preprints and abstracts published in reputed journals and reported on many Russian and International scientific conferences.

Abstract:

Surface enhanced optical processes SERS, SEHRS, SEIRA and single molecule SERS are of great interest. At present we have a reliable base in order to assert that their enhancement is associated with so-called strong quadrupole light-molecule interaction, arising in surface optical fields, arising near rough surfaces. The reason of appearance of these fields is a disordered medium where the characteristic size of the change of the electromagnetic field is equal to the characteristic length of the roughness. It appears that there is a strong enhancement of the electric fields and its derivatives in such a medium, especially near the places of substrate with a very large curvature. The second reason of the enhancement is an exclusive role of the quadrupole moments of the  and  type, which are of a constant sign that results in a strong increase of their matrix elements with respect to the ones of the dipole moments  and quadrupole moments  and , which are of a changeable sign. The increase of the number of moments, which are involved in the scattering results in appearance of forbidden lines in all the above processes. It appears and is confirmed experimentally that there are strong forbidden lines in symmetrical molecules with sufficiently high symmetry in SEIRA and SEHRS, which refer to the unit irreducible representation of the molecule symmetry group and the SERS lines, which refer to the vibrations with the irreducible representations describing transformational properties of the dipole moments. The last indicated lines are active in a usual IR absorption and are inactive in a usual Raman scattering. In addition the strong quadrupole light-molecule interaction experiences so-called electrodynamical forbiddance in molecules with cubic and icosahedral symmetry groups that results in the absence of the above mentioned lines in SERS, SEHRS and SEIRA spectra of molecules like methane, or fullerene . Analysis of experimental SERS and SEIRA spectra of  strongly supports this result. 

Biography:

D A Pawlak is a Professor at the Institute of Electronic Materials Technology (ITME) of Warsaw, and at the Centre of New Technologies (CeNT), University of Warsaw in Poland. She is currently the Head of the Department of Functional Materials at ITME and Leader of the Laboratory of Materials Technology at CeNT. Her research is linked to technology development for the manufacturing of new functional materials, such as plasmonic materials, metamaterials, materials with special electromagnetic properties and materials for solar energy conversion. She currently focuses on bottom-up methods such as directional solidification and crystallization, nanoparticles direct doping method and associated research.

Abstract:

We report on developments of fabricating nano and micro-structured volumetric plasmonic materials, metamaterials and other materials with unusual electromagnetic properties, utilizing crystal growth techniques based on directional solidification and crystallization. Two types of materials will be discussed: (i) based on directional solidification of eutectic composites, and (ii) directional solidification of dielectrics directly doped with functional nanoparticles of various size, shape and chemical composition (metallic-plasmonic, quantum dots) as well as various additional elements as rare earths, obtained by the nanoparticles direct doping (NPDD). It has been shown that with self-organization mechanism during the eutectic crystallization various shapes pertinent to metamaterials can be obtained as the 'split-ring resonator' geometry, rodlike or lamellar structures which can be used as hyperbolic metamaterials, or for subwavlength transmission of electromagnetic waves, eutectic-based tunable nanoplasmonic materials have been demonstrated for the first time, as well as enhanced second harmonic generation, strongly enhanced Faraday effect and others.

Biography:

Amir Arbabi is currently a Senior Researcher at Caltech. From January 2017, he will be an Assistant Professor at the University of Massachusetts, Amherst. He received PhD degree in Electrical Engineering from University of Illinois at Urbana-Champaign. He has authored and coauthored over 70 papers in peer reviewed journals and conferences. His current research interests include photonic integrated circuits and on-chip integration of free space optical elements and systems.

Abstract:

Flat optical devices based on lithographically patterned sub-wavelength dielectric nano-structures provide precise control over optical wavefronts, and thus promise to revolutionize the field of free-space optics. Here, I have discussed our work on high contrast transmit-arrays and reflectarrays composed of silicon nano-posts located on top of low index substrates like silica glass or transparent polymers. Complete control of both phase and polarization is achieved at the level of single nano-post, which enables control of the optical wavefront with sub-wavelength spatial resolution. Using this nano-post platform, we demonstrate lenses, wave-plates, polarizers, arbitrary beam splitters and holograms. Devices that provide multiple functionalities, like simultaneous polarization beam splitting and focusing are implemented. By embedding the metasurfaces in flexible substrates, conformal optical devices that decouple the geometrical shape and optical function are shown. Multiple flat optical elements are integrated in optical systems such as planar retro-reflectors and Fourier lens systems with applications in ultra-compact imaging systems. Applications in microscopy and the prospects for tunable devices are discussed.

Biography:

Michelle R Stem has a PhD in Materials Science Engineering, MBA in Management and BS in Chemistry. She has done her Post-doctoral Research and continued work as a Senior Materials Researcher at Complete Consulting Services, LLC. She applies interdisciplinary expertise through multi-scale analysis, computational modeling, and laboratory synthesis to study extremely rare inorganic, complex, and semi-conductor (ICS) materials. She researches ICS structural and property variations to discover and ultimately engineer new methods, applications, models, materials, and metamaterials with the goal of controlling photonic, optoelectronic, band gap and other properties. In addition to this, she also does research to develop materials that save energy (e.g. power differentials for photonic band gap versus electronic materials) and finds alternatives to using up rare resources.

Abstract:

This presentation will discuss the search, discovery, exploration and examination of the photonic control properties of natural, untreated opals having properties that were previously thought to exist only in artificially created materials. I will discuss the discovery of the first truly natural, untreated materials displaying: negative-index metamaterial, anti-Stokes upconversion, photonic glass, spontaneous laser emissions, and microspheroid cluster boundary effects. These materials display these photonic properties in visible light frequencies, with no toxic elements, in ambient conditions, and with significantly high energy conversion efficiency. Natural materials with such photonic control may be developed for broader applications in solar power, space exploration, energy production, stealth technologies, waveguides, microscopy, and photonic data storage/transmission.

Biography:

Shu-Wei Huang is an Assistant Research Professor at the University of California, Los Angeles, with research interests in ultrafast lasers, nanophotonics, THz technologies, and nonlinear spectro-imaging. He has received his BS degree from National Taiwan University (2005) and his PhD degree from Massachusetts Institute of Technology (2012), both in Electrical Engineering. He was awarded the 2012 Jin-Au Kong Outstanding Doctoral Thesis Prize for breaking the single-cycle barrier in high-energy coherent light sources. In 2015, he received the Air Force Young Investigator Grant for his investigations in microresonator-based optical frequency comb. Currently, he serves as the Webinar Co-chair of OSA’s Nonlinear Optics Technical Group.

Abstract:

Optical frequency comb, a Nobel Prize awarded research, is a new time and frequency standard with unprecedented precision. It has been the cornerstone for breakthroughs in ultrastable time keeping, astrophysical spectrography, attosecond sciences, high-precision navigation, high-capacity coherent communication, and high-speed nonlinear spectro-imaging. Recently, continuous-wave pumped microresonators emerge as promising alternatives to the current benchmark femtosecond laser platform. These photonic frequency combs are unique in their compact footprints and offer the potential for monolithic electronic and feedback integration, thereby expanding the already remarkable applications of optical frequency combs. In this talk, I will present my recent work on photonic frequency combs. I will first report the generation of stable 74-fs optical pulses from a Si₃N₄ microring resonator via numerical modeling and analytic theory, the connection between the microresonator parameters and the ultrashort pulse qualities. I will also report a low-phase-noise photonic frequency comb with 18 GHz comb spacing, compatible with high-speed silicon optoelectronics. I will describe the strategy to fully stabilize the photonic frequency comb and achieve a chip-scale optical frequency synthesizer with a relative uncertainty of 2.7×10^-16. Finally, I will cover the future endeavour towards chip-scale precision metrology.

Biography:

P Boolchand has received his PhD in Physics from Case Western Reserve University in 1969. He is a Professor of Electrical, Computer Engineering and Physics at University of Cincinnati. He has held Visiting Positions at Stanford University, University of Paris and Katholieke University of Leuven. He has co-authored over 275 journal publications. He is Fellow of the American Physical Society, and recipient of the Stanford Ovshinsky Award 

Abstract:

Three topological phases of network glasses, flexible, intermediate and stressed-rigid are now widely recognized in chalcogenide and modified oxides. These are manifested as network connectivity is steadily increased in the 2 < < 2.67 range. Here the mean coordination number , serves as a measure of network connectivity, and can be tuned by chemical composition. Near = 2.40, and over a small but finite range of called the intermediate phase (IP), networks acquire unusual functionalities; they exhibit high glass forming tendency, acquire a vanishing enthalpy of relaxation at T_g to display square-well like thermally reversing windows, become isostatically rigid and stress-free. Furthermore, the fragility index (m) of chalcogenide melts displays a global minimum (m<20) for IP compositions. One then recognized that IP melts possess high viscosity and undergo slow homogenization. Raman scattering of dry chalcogenide melts encased in evacuated quartz tubes examined along the length of a melt column show that even 2 gram sized batches when reacted at 200-300ºC above the liquidus take nearly a week of reaction time for observed line shapes to become identical or batch compositions to homogenize. In dry and homogeneous chalcogenides (Ge-Se, Ge-S and Si-Se) the IP boundaries are abrupt, while in heterogeneous ones these are usually smeared. In modified-oxides, traces of bonded water lead to a narrowing or even collapse of the IP. In dry and homogeneous glasses IP boundaries are sharp and these self-organization effects are reflected in a variety of physical properties. 

Biography:

Renee Charriere has completed her PhD in Optics and Quantum Mechanics in 2011 from the French Aerospace Lab (Office National d’Etudes et de Recherches Aérospatiales) and Paris VI University. As a Post-doctorate, she has worked on the optical characterization and modeling of nanostructured surfaces with complex visual appearance. She is now an Assistant Professor at the French Laboratory Georges Friedel in Saint-Etienne and is currently a Guest Researcher at National Institute of Standards and Technology in USA.

Abstract:

Gonio-apparent surfaces are characterized by huge variations of their visual rendering depending on illumination and observation directions. Such surfaces are more and more employed in industry for aesthetic reasons. Hotel Marqués de Riscal d’Elciego in Spain, for example, is covered by anodized titanium plates, which give the building a color change with sun position. The optical and colorimetric characterization of these materials is tricky as their optical properties vary highly with the illumination and/or observation geometries. Georges Friedel Laboratory has developed a high resolution optical device dedicated to the measurement of the bidirectional reflectance distribution function (BRDF) of such materials. This optical device has allowed the characterization of the color variations of gonioapparent materials such as anodized titanium and nanostructured anodized aluminum. Chromatic paths of the colors of the material as a function of illumination and observation direction have been deduced from the BRDF measurements. Electromagnetic models of the optical properties of these materials have been developed, showing good accordance with BRDF measurements. It has been for example demonstrated  that it is possible to adapt the Fourier modal method, which is generally dedicated to the modelling of periodic nanostructures, to the partially ordered structure exhibited by nanostructured anodized aluminum. 

Biography:

Yukihiko Yamagata has his expertise in Atomic and Molecular Physics, especially in Laser-aided Diagnostics. He has completed his PhD from Kyushu University, Japan. He is an Associate Professor and Leader of a Research Project focusing on standard measurement technology for solid state lighting devices in the Department of Engineering Sciences for Electronics and Materials, Kyushu University, Japan.

Abstract:

Recently, the characteristic of a light emitting diode (LED) has been improved dramatically, and the application to illumination is recognized as one of the most important issue to the manufacturers. It is well known that the efficiency, the output power, the life-time and the reliability of LED degrade with a temperature rise of the junction of LED. In order to fabricate a high quality LED module for illumination, it is necessary to keep the junction temperature low by improving the characteristic of LED chip itself, or by effective heat removal through a heat radiation design of the module. Therefore, it is strongly required to establish a standard method to measure the junction temperatures in LED module. Although several techniques, such as micro-Raman spectroscopy, infrared imaging, and temperature coefficient of diode-forward voltage are applied to estimate the junction temperature, there is no method that can simultaneously measure the junction temperature of the several chips located in a LED module, especially in a phosphor-deposited white-LED. Under these situations, we have been developing a pulsed-laser Raman scattering method for estimation of the junction temperature of LED, where the Raman shift of E₂^H mode of GaN layer is observed. This method has potentials of remoteness and simultaneous multipoint measurement, which lead to 2D mapping of the temperature of the LED module. This technique has been applied successfully to measure the junction temperature of phosphor-less blue-LED, and is considered to be one of the prospective candidates of temperature estimation method of white-LED. In this presentation, simultaneous observation of Raman spectra from several LED chips in a phosphor-less blue-LED module by a pulsed-laser Raman scattering method is demonstrated. Also, the influence of a phosphor deposited on the surface of blue-LED on Raman spectra will be discussed.

Biography:

Ken-ichi Harada has completed his PhD degree from Kumamoto University in Japan and joined the NTT Basic Research Laboratories. From 2010, he has been working at CYRIC, Tohoku University, as an Assistant Professor and then as a Lecturer. His research interests are in the fields of spectroscopy of atoms and molecules, laser cooling and trapping, fundamental symmetry violation studies, optical magnetometry, electro-optics devices and silicon photonic devices. He has published more than 33 papers in peer-reviewed journals.

Abstract:

The investigation of fundamental symmetry violations can elucidate the new physics beyond the standard model. Laser cooled and trapped Fr atoms have particular advantages for the precise symmetry violation measurements. Fr isotopes have ground state hyperfine splitting of about 46 GHz. For achieving laser cooling and trapping of Fr atoms, the hyperfine splitting frequency has to be accurately measured. The frequency difference of 46.1 GHz (²¹⁰Fr) has to be bridged by two different lasers or has to be generated from a single laser by an electro-optic modulator (EOM). However, it is difficult to generate a frequency component with 46 GHz at the first sideband with an EOM in order to stabilize the frequency difference. In this work, we demonstrated the laser frequency locking with 46 GHz offsets between the trapping and re-pumping lights by generating a 10^th order sideband using a fiber-based single-pass waveguide EOM. We successfully obtained the frequency locking error signal by performing delayed self-homodyne detection of the beat signal. Sweeping the trapped-light and re-pumping-light frequencies with keeping its frequency difference of 46 GHz was confirmed over 1 GHz by monitoring the Doppler absorption profile of iodine molecule. This technique enables us to search for a resonance frequency and magneto-optical trapping of Fr atoms. This can be applied for other radioactive as well as stable atoms with large hyperfine splitting.

Biography:

Devki N Talwar, is a Distinguished University Professor in the Physics department at Indiana University of Pennsylvania (IUP), USA and conducts research on defects in semiconductor materials used in various electronics and optoelectronics applications. He has been with IUP for almost 29 years, and is the author of more than 130 refereed journal articles, four book chapters and more than 80 international conference presentations. He served as an Organizer in seven international conferences organized by Materials Research Society-USA, Singapore; 5^th World Congress on Materials Science and Engineering-Spain, Optics, Mesoscopic Condensed Matter Physics, and Condensed Matter Physics-USA. He was invited as Honorary Guest member in Science Conclave with Nobel Laureates at IIIT-Allahabad from 2009-2014 and has delivered keynote addresses at Moscow Institute of Science and Technology and many other international conferences. His expertise in the sophisticated Green’s function technique is considered very useful for providing information on the electronic and vibrational properties of defects in semiconductors, quantum wells, and superlattices. He is recognized by the international community as a prolific researcher.

Abstract:

We report comprehensive studies of the optical and structural properties of microstructures in V-CVD grown 3C–SiC/Si (001) epifilms by exploiting Raman scattering and X-ray absorption fine structure measurements. By exploiting the phonon-assisted Raman scattering spectroscopy we have recognized the conventional optical modes ~794 cm^-1, 973 cm^-1 and two additional phonon features near ~ 625 cm^-1 and 670 cm^-1 - possibly falling between the forbidden gap of the acoustic and optical branches of 3C-SiC. Synchrotron radiation X-ray absorption fine-structure (SR-XAFS) measurements are performed by exploiting a double-crystal monochromator beamline at the National Synchrotron Radiation Research Center, Hsinchu, Taiwan. The measured X-ray absorption spectra are carefully examined to check the ability of experimental standards with the ab initio calculations. Temperature dependent profile of the unresolved ~670 cm^-1 Raman band indicates disordering by defects and/or stress that makes phonon lifetime shorter to instigate mode broadening. Accurate assessments of lattice dynamical, thermal and defect properties are achieved by exploiting phonons from a rigid-ion model fitted to the inelastic X-ray scattering data and expending apposite group-theoretical selection rules. Lattice relaxations around Si/C atoms attained by first-principles bond-orbital model for isolated defects have helped evaluating the necessary force constant variations to construct perturbation matrices of “complex-defect-centers”. For the isolated intrinsic C_Si and Si_C defects (T_d-symmetry) our methodical greens function (GF) theory predicted triply degenerate F₂ gap modes near ~630 cm^-1 and ~660 cm^-1, respectively. The GF simulations of impurity vibrations for a neutral “anti-site” C_Si-Si_C pair (C_3v-symmetry) provided gap-modes to appear within the broad ~670 cm^-1 band at 664.8 cm^-1 (a₁) and 660.6 cm^-1 (e). These outcomes implying possible links of ASP defect to a proto-typical D_I center in 3C-SiC are compared and deliberated against the existing experimental data. 

Biography:

Young-Ho Seo has received his MS and PhD degrees in 2000 and 2004, respectively from Department of Electronic Materials Engineering of Kwangwoon University in Seoul, Korea. He was a Researcher at Korea Electrotechnology Research Institute (KERI) in 2003 to 2004. He was a Research Professor of Department of Electronic and Information Engineering at Yuhan College in Buchon, Korea. He was an Assistant Professor of Department of Information and Communication Engineering at Hansung University in Seoul, Korea. He is a Full Professor of Ingenium College of Liberal Arts at Kwangwoon University in Seoul, Korea and a Director of Research Institute in DSI Tech Inc. Hi is now a Visiting Professor in University of Nebraska at Omaha, NE, USA. His research interests include realistic media, digital holography, SoC design and bus architecture.

Abstract:

Computer-generated holography is a method of digitally generating interference fringe patterns. Recently, the term of “computer-generated holography” has been used to present the whole process of preparing holographic light wavefronts suitable for various displaying. The resultant images generated by the computer-generated holography are called computer-generated hologram (CGH). In case of generating synthetic holograms, the CGHs have the advantage that the objects don’t need to possess any physical reality at all. In case of optically generating a hologram from existing objects, if it is digitally recorded and processed or displayed, this is corresponding to the CGH as well. Wavefront calculations for the CGHs are computationally very intensive. Although the researchers use modern mathematical techniques and high-performance computing equipment, real-time operation is very difficult according to the amount of the object points. There are many various methods for calculating the interference pattern for a CGH. Among them, we use the point source method. In this paper, we propose a new hardware architecture to generate CGHs based on the block based calculation method and implement a VLSI (very large scaled integrated circuit) in ASIC (application specific integrated circuit) environment. The proposed hardware has a structure that can produce a part of a hologram in the unit of a 12x12 block in parallel. After calculating a block of a hologram by using an object point, the calculation is repeated to all object points and intermediate results from them are accumulated to produce a final block of a hologram. Through this structure, we can make various sizes of holograms with the optimized memory access in real-time operation. The proposed hardware was implemented in the Hynix 0.18 um CMOS technology of MagnaChip Inc., and has 876,608 gate counts. It can generate complex holograms unlike the previous researches and stably operate in the clock frequency of 200 MHz.

Biography:

I Filikhin is a Research Professor in the Department of Physics at North Carolina Central University. He received his Doctorate in Theoretical Physics from St. Petersburg State University in Russia (1993). His research includes nuclear low-energy physics, hyperphysics, nano-science and semiconductors physics, as well as computational physics. He is author/coauthor of more than 90 scientific papers. His current researches are related to the effective potential approach for electron structures in complexes of the quantum dots and rings, cluster models for light nuclei and hypernuclei. 

Abstract:

We studied the electron localization and spectral distributions of electron localized/delocalized states in binary InAs/GaAs quantum complexes. Such weakly coupled binary systems demonstrated perspectives for nano-sensor applications. Electron tunneling in double quantum dots (DQDs) and quantum wells (DQWs) was studied with dependence on distance between QDs. We showed that the tunneling between identical QDs in DQD goes consecutively from the higher energy levels to the ground state when the inter-dot distance is decreased. The case of non-identical QDs in DQD has an essential difference and the relation between these two cases is discussed. Generally, the violation of symmetry of the DQD geometry reduces tunneling. In particular, we found that electron tunneling is extremely sensitive on shape symmetry violations in binary systems, which can be potentially used for nano-sensing. To investigate the method of detection of the localized/delocalized states change we considered the electron tunneling in InAs/GaAs dot-well complex. Modeling of carrier transfer from the barrier in InAs/GaAs dot-well tunnel-injection structures was performed. A relation between the experiment and our calculations will be presented and perspectives to use the method for nano-sensor applications will be discussed. 

Biography:

Goran Rasic has received his PhD in 2014 from NC State University and is currently a NSF Post-doctoral Fellow at NC Central University. His research interests include nanoscale lithography, novel manufacturing techniques and magnetic and multiferroic thin films for device applications. He has published 8 papers, one book chapter and two patents.

Abstract:

Micro- and nanolithography techniques are a key factor in pushing the limits of science and technology. This is especially true in the semiconductor industry which has made remarkable progress over the last 20 years. With the technology focus moving to smaller and smaller scale, numerous lithography methods of manufacturing complex micro- and nanostructures (such as photo, nanoimprint, e-beam, soft and focused ion beam) have been developed. However, most of these techniques have limitations in the form of material choices, speed, cost and/or pattern shape/size. Clearly a fast, low-cost and versatile method of producing high quality surface patterns is needed. Here, an approach that offers low-cost, fast manufacturing of complex patterns over large scale is presented. The method proposed can be used to directly describe the desired pattern on the light sensitive material or create a master to be used for transferring a pattern to the appropriate material. The desired motif is drawn on a computer and transferred to the photoresist using our setup consisting of commercially available LED laser. Surface of the material can then be engraved with the predetermined pattern using standard etching techniques. The method described here represents an affordable, fast and versatile way of manufacturing complex micro- and nanostructures without some of the design, throughput and material limitations faced by costlier techniques, making state of the art research more affordable and accessible.

Biography:

Peng-Sheng Wei has received his PhD in Mechanical Engineering department from University of California, in 1984. He was a Professor in the Department of Mechanical and Electro-mechanical Engineering of National Sun Yat-Sen University, Kaohsiung, Taiwan, since 1989. He has contributed to the understanding and applications of electron and laser beam, plasma, and resistance welding through theoretical analyses coupled with verification experiments. He has published more than 80 journal papers and has given keynote or invited speeches in international conferences more than 70 times. He is a Fellow of AWS (2007), and a Fellow of ASME (2000). He also received the Outstanding Research Achievement Awards from both the National Science Council (2004), and NSYSU (1991, 2001 and 2004), the Outstanding Scholar Research Project Winner Award from National Science Council (2008), the Adams Memorial Membership Award from AWS (2008), the Warren F Savage Memorial Award from AWS (2012), and the William Irrgang Memorial Award from AWS (2014). He has been the Xi-Wan Chair Professor of NSYSU since 2009, and is an Invited Distinguished Professor in the Beijing University of Technology, China (2015-2017).

Abstract:

This study theoretically identifies the factors affecting the keyhole collapse during drilling with a high power density laser beam. Laser drilling is widely used in various manufacturing technologies. This work studies quasi-steady one-dimensional compressible flow behavior of the two-phase vapor-liquid dispersion in a vertical keyhole of varying cross-section, paying particular attention to the transition between the annular and slug flows. The results find that the effects of transport processes across the induced keyhole wall affected by surface tension, friction force, and liquid entrainments on incapability of drilling. The predicted results agree with physical intuition and exact closed-form solutions in the absence of friction and energy absorption. Controlling the factors to enhance efficiency and quality of drilling is therefore provided in this work.