Day 1 :
Keynote Forum
Artur V. Gleim
ITMO University, Russia
Keynote: Multi-mode optical quantum memory for quantum processing and communication
Time : 08:35-09:05
Biography:
TBA
Abstract:
The promising approaches for multi-mode optical quantum memory and its use in quantum processing and communication are discussed. Herein, we are interested in specific properties of the recently developed photon echo schemes in solid state and gaseous media. The photon echo approach opened a number of convenient protocols for storage of multi-mode light fields such as well-known CRIB-, GEM- and AFC-protocols and approaches using atomic systems with natural inhomogeneous broadening of resonant transitions such as ROSE-type –protocols. We discuss basic properties, advantages and difficulties of these protocols, new experimental achievements in these schemes and possible progress in its future development. Here we consider new realizations using particular properties of resonant systems used for quantum storage and different types of the light-atom interactions. At first, we propose convenient experiment realizations of efficient broadband ACF-protocol. A special attention, we paid to off-resonant Raman interaction of light fields with atomic systems for considerable improvement of the photon echo QM schemes. Here, we discuss new properties of the Raman echo QM in free space and in the optical cavity schemes. In particular, we are interested in the properties of multi-color, associate multi-mode QM, and efficient wavelength conversion. Also, we elaborate new approach for realization of broadband photon echo quantum storage in optical cavity. In our analysis, we discuss importance and role of time-reversal dynamics in the light-atom interactions for high quantum efficiency and fidelity in light field storage. Finally, we discuss a potential realization of the studied photon echo schemes in the planed experiments on the inorganic crystals doped by rare-earth ions and potential application of these schemes for quantum repeaters and quantum processing.
Keynote Forum
Carl Christoph Jung
CCJ Software, Germany
Keynote: About exploration of thin layer orientation in transparent films
Time : 09.30-010.20
Biography:
TBA
Abstract:
Display components and other thin coatings can exhibit a very complex and subtly hidden inner setup.rnTo discover the state of the layers in a thin film mainly by optical means has now beenrnfacilitated by the invention of Immersion Transmission Ellipsometry
Keynote Forum
Markus Pollnau
KTH – Royal Institute of Technology, Sweden
Keynote: Dielectric waveguide lasers: The realm of efficiency
Time : 09:35-10:20
Biography:
Markus Pollnau received MSc and PhD degrees in Physics from University of Hamburg, Germany (1992) and University of Bern, Switzerland (1996), respectively. In 2004, he became a Full Professor at the University of Twente, The Netherlands and moved to KTH, Sweden, in 2014. He has contributed to more than 500 reviewed journals and international conference papers on crystal and thin-film growth, rare-earth-doped lasers and waveguide fabrication, devices and applications. He served as General Co-chair of the Conferences on Lasers and Electro-Optics (2008), Lasers and Electro-Optics Europe (2011) and the Europhoton Conference (2004). He is a fellow of OSA and EPS.
Abstract:
Rare-earth ions have been widely exploited for amplification and lasing on various electronic transitions from the near-ultraviolet to the mid-infrared spectral region. The small transition cross sections of rare-earth ions result in a large absorption length of pump light, thus dictating an accordingly long interaction length with the active material to exploit the delivered pump power. In the past two decades, waveguide geometries that rely on the total internal reflection of pump and signal light on their propagation through the active material have become very successful. These geometries allow for tight pump- and signal-light confinement, hence high optical pump intensities and excellent overlap between pump and signal beam over very long interaction lengths, thereby ensuring good pump absorption and enabling a low threshold and high efficiency. The excellent performance of these devices is based on careful analysis and exploitation of the specific spectroscopic properties of the utilized rare-earth ion. Recent examples include a Tm-doped potassium double tungstate channel waveguide laser with an active ion concentration of 8%, thus ensuring efficient cross relaxation of 800-nm-pump excitation and resulting in record-high slope efficiency for any Tm-doped laser of ~80%. Furthermore, distributed-feedback and distributed-Bragg-reflector narrow-linewidth channel waveguide lasers were demonstrated in Er- and Yb-doped amorphous aluminum oxide on a silicon wafer by inscribing a uniform Bragg grating into the silicon oxide top cladding, with laser linewidths down to 1.7 kHz and slope efficiencies up to 67%.
- Photonics
Location: July 28, 2016- Embassy I+II
Chair
Bruno Bêche
Université de Rennes, France
Co-Chair
Michael Giersig
Helmholtz-Zentrum Berlin, Germany
Session Introduction
Guangwen Huo
Xijing University, China
Title: A generalized method for calculating phase matching conditions in biaxial crystals
Time : 10:35-10:55
Biography:
Guangwen Huo has completed his PhD degree (Master–Doctor combined program) from the Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences in 2014. He is now a Lecturer working at the College of Control Engineering, Xijing University. He has published more than 10 papers on nonlinear crystals in reputed journals. His main works include quantum optics, quantum calculating and quantum information.
Abstract:
We present a generalized method for calculating phase matching conditions in biaxial crystals, especially in nonlinear monoclinic and triclinic crystals. Exploiting the angle definition introduced by Japanese mathematician Kodaira Kunihiko, we deduce the angular relations in geometry and obtain the expressions of refractive indices depending on angular orientation of wave vector k and optical axis angle. Then we calculate the phase matching parameters with bismuth borate BiB3O6 (BIBO) crystal in spontaneous parametric down conversion (SPDC) process for the type I and type II. On its basis, we discuss the angular gradients of the pump and emission wave refractive index near the exact phase matching direction, and compare the SPDC with double frequency process in geometrical relations of the refractive index ellipsoids. It indicates the anisotropic structures of nonlinear crystals making a capability of filtering effect, and the nonzero linear mismatch described by refractive index angular gradients can be used to estimate the beam width in crystal. This method is convenient to calculate the phase matching parameters in orthorhombic crystals without solving the quadratic Fresnel equations.
Michael Giersig
Helmholtz-Zentrum Berlin, Germany
Title: Electromagnetic waves interaction with various metallic nanomaterials
Time : 10:55-11:15
Biography:
Michael Giersig has published over 258 internationally refereed publications covering physics, chemistry, materials science, biochemistry, medicine, nanotechnology and engineering. His work has been cited 18051 times quoted in the ISI Index (without self-citations) at an average of over 714 citations per publication, while his H-index is currently 71. He is listed in position 75 in chemistry and 83 in material science in the World Ranking by Thomson Reuters of the 100 Top Chemists and Material Scientists of the past decade 2000-2010.
Abstract:
In this lecture, we will discuss our recent study about the plasmoelectric effect where optical energy can be converted into electrical potential differences in the absence of semiconductors. The active interactions have been visualized by illumination of various in size and morphologies of periodic perforated metallic films by monochromatic light. The nanostructure films have been created by nanosphere lithography (NSL) in conjunction with plasma etching and physical vapor deposition methods. The metallic nanostructures can effectively confine the radiation to nanoscale in the proximity of plasmon resonance whereby the position of this resonance is controlled by the morphology (size and shape) of the nanostructures. The surface potential measurement resulting in enhancement of local fields was analyzed by using Kelvin probe force microscopy (KPFM) under simultaneous illumination in the energy range of the plasmon resonance peak of our nanomaterials towards observing plasmoelectric effects. The recent observation of an enhanced photon induced voltage on Au grating and the second harmonic generation suggests that the overall shape of the structures plays a significant role in determining nonlinear response.
Vladimir B Karalnik
Troitsk Institute for Innovation and Fusion Research (SRC RF TRINITI), Russia
Title: Ultrahigh charging of small spherical grains by the beam-plasma method for creating a compact neutron source
Time : 11:15-11:35
Biography:
Vladimir B Karalnik was graduated from Moscow Institute of Physics and Technology, USSR, in 1990. He received the PhD degree in Physics and Mathematics in 2008 from SRC RF TRINITI. He is currently a Leading Research Scientist with SRC RF TRINITI. His research interests include gas discharge physics and numerical calculations of non-equilibrium plasma interacting with gaseous, liquid and solid objects. He has published more than 90 papers in reputed journals.
Abstract:
Generation of high-voltage high-current electron beams in a low-pressure (0.1-1 Torr) gas discharge is studied experimentally as a function of the discharge voltage and the sort and pressure of the plasma forming gas. The density of the plasma formed by a high-current electron beam is measured. Experiments on ultrahigh charging of micro-particles exposed to a pulsed electron beam with an energy of up to 25keV, an electron current density of higher than 1 A/cm2, a pulse duration of up to 1μs, and a repetition rate of up to 1 kHz are described. Spatial evolution of an electron beam in the course of its propagation towards the target is investigated. A numerical model of ultrahigh charging of grains with a radius of 250μm exposed to a high-energy electron beam is developed. The formation of high-energy positive ions in the electric field around of spherical targets is calculated. The calculations performed for a pulse-periodic mode demonstrate the possibility of achieving neutron yields about 109s–1 in the case of 103 spherical grains.
Kevin Dupraz
Centre national de la recherche scientifique, France
Title: The ABCD matrix for parabolic reflectors and its application to astigmatism free four-mirror cavities
Time : 11:35-11:55
Biography:
Kevin Dupraz has completed his PhD a year ago from University of Paris-Sud in Orsay, France. He works presently on the design of the Laser Beam Circulator of the ELI-NP gamma beam source and on the X-ray characterization of the X-ray line of the ThomX machine. He is Research Associate in a dynamic team focusing on the laser-electron interaction.
Abstract:
Recent researches have demonstrated the possibility to use resonant cavity in a novel mode named burst mode. This mode is a mean to increase the laser peak power staked in the cavity. High peak power has also been obtained by increasing the incident average power. Consequently the staked power in resonant cavity can now reach the damage threshold of the mirrors. This limitation can be overcome by means of large beam mode-size on the optics. On the other hand a larger beam mode-size usually induces a larger astigmatism for folded cavities composed of spherical mirrors. In order to enlarge the spot size and maintain low astigmatism, an optical cavity composed of aspherical mirrors can be considered. The most common and easiest to produce is parabolic mirrors. The main drawback of this type of mirror is alignment issues. Moreover in aim to design the cavity geometry and check the beam mode-size there is no ABCD matrix for parabolic reflectors derived for any incident angles. I will describe how to derive this ABCD matrix by mean of basic considerations and using formalism from quantum billiard. This derivation method is general and can also be used for other aspherical shapes. Then a numerical study of four-mirror cavities composed of two flat and two parabolic mirrors will be described. I will show that this cavity satisfies all constraints related to laser beam injection efficiency, optical stability, cavity-mode, beam-waist size and high stacking power to be a reliable resonant cavity. Finally a dedicated alignment procedure leading to stigmatic cavity-modes is presented to overcome issues related to the optical alignment of parabolic reflectors.
Bruno Bêche
Université de Rennes, France
Title: Soft matter for integrated photonics and resonances: Various hybrid approaches and adaptive technologies
Time : 11:55-12:15
Biography:
Bruno Bêche is Professor of Physics at the University of Rennes 1 (IPR CNRS 6251). His teaching activity took place in several universities as well as in engineering schools in France, holding lectures in fundamental physics, physics of materials, and also photonics at all student levels of education. His research career started on the development of optical components based on lithium niobate as non-linear optical devices and then he worked in the development of III-V semiconductors as components for the wavelength division, multiplexing and lasers (FEMTO-ST and LAAS CNRS, France and NTT Corporation, Japan). At the University of Rennes 1, he started a new field of research, working since a few years in the development of various micro-resonators based on hybrid technologies which combine the use of polymers and plasma treatments, soft matter with fluidic and biology concepts. His research work covers both the theoretical description of the physical aspects of these photonic devices and also the technologies, the characterization and their applications as integrated biosensors in metrology. He is Honorary Member of the 'Institut Universitaire de France' - IUF Paris.
Abstract:
Integrated photonics is increasingly used in sensors and metrology applications. Moreover, the ability to develop new photonic devices through simple, low cost and mass production fabrication steps based on new materials and hybrid approaches is substantial. We will give an overview of targeted current research on integrated photonics based on various hybrid technologies so as to develop multiple families of resonant integrated structures called resonators shaped in 2D or 3D. Such devices devoted to optical resonances and sensors applications and their solving approach highlight the interest to develop specific hybrid processes such as nano-biomolecular film deposition as lipids, self-assembled and micro-fluidic devices, plasma treatments coupled with micro-technology thin layers processes using deep UV lithography and so on.
Mikhail Kaliteevski
ITMO University, Russia
Title: Quantization of electromagnetic field in an inhomogeneous medium based on scattering matrix formalism (S-quantization)
Time : 12:15-12:35
Biography:
Mikhail Kaliteevski has completed his PhD from Ioffe Institute, St-Petersburg, (Russia). He is principal research scientist and head of research team focusing on nanophotonics in Academic University, Ioffe Institute and ITMO University. He has published more than 150 papers in reputed journals and serving as an Editorial Board Member of repute.
Abstract:
We have developed a procedure for quantization of the electromagnetic field in a layered inhomogeneous media based on analysis of the Eigen values of the scattering matrix (S-matrix). In contrast to the method involving quantization of the electromagnetic field, involving the use of periodic boundary conditions (Born–von Karman conditions), the proposed procedure (S-quantization) is based on equality of the amplitudes of waves incident on a quantization box and waves outgoing from the quantization box, which is equivalent to equating unity Eigen values of the scattering matrix. We perform a comparison of the density of states and spatial structure of the field calculated with periodic boundary conditions and using the procedure of S-quantization. S-quantization allows calculating modification of the spontaneous emission rate for arbitrary inhomogeneous structure and direction of the emitted radiation. S-quantization solves the long-standing problem coupled to normalization of the quasi-stationary electromagnetic modes. Examples of application of S-quantization for the calculation of spontaneous emission rate for the cases of Bragg reflectors, micro-cavities, photonic quasi-crystals and plasmonic structures are demonstrated.
- Types of Lasers | Lasers in Industry
Location: July 28,2016- Embassy I+II
Chair
Stephan Bruening
Schepers GmbH & Co. KG, Germany
Co-Chair
Belkacem Meziane
Université d’Artois, France
Session Introduction
Bernhard Roth
Leibniz University Hannover, Germany
Title: All-polymer planar optical sensing devices integrated in thin foils
Time : 12:35-12:55
Biography:
Bernhard Roth obtained his PhD in 2001 at University Bielefeld. From 2002-2007, he served as Group Leader at University Duesseldorf and obtained his Habilitation in Quantum Optics in 2007. From 2007-2010, he worked as Associate Professor at University Duesseldorf and from 2011-2012 as Managing Director at the research centre innoFSPEC, University Potsdam and Leibniz Institute for Astrophysics Potsdam. Since 2012, he is Director of the Hannover Centre for Optical Technologies and since 2014 serving as Professor at the University Hannover. His scientific activities include research in laser development and spectroscopy, polymer optical sensing and optical technology for illumination, information technology and the life sciences.
Abstract:
Planar optical sensor devices integrated into thin polymer foils hold great promise for a wide range of new applications in structural health monitoring for buildings and aircraft or process control in production environments and the life sciences. Various such applications demand for fully integrated, large area optical foils with extensive optical sensor functionality. Therefore, the primary challenge is to develop sensor concepts which translate the physical and chemical parameters into optical signals, such that the resulting sensor networks will allow large-area, spatially-resolved measurements, and to manufacture and integrate all components required, e.g. laser sources, detectors, optical waveguides and coupling elements into thin foils, ideally using high-volume, roll-to-roll manufacturing technology. Consequently, research in the field has been very active during the last few years and, besides the investigation of suitable optical sensor concepts, revolves about the development of novel production technologies, often through combination of modern laser technology and state-of-the-art micro-structuring, as well as concepts for large-area integration. In my talk, I will give an overview on our research in this field. Our activities range from the realization of efficient optical waveguides and coupling elements using laser and hot embossing techniques, the development, simulation and demonstration of all-polymer optical sensor devices for detection of, e.g., strain, humidity, or concentration to combination of such systems to more complex arrays intended for distributed 2D sensing. I will present some of the results we recently obtained and discuss the next steps of our work as well as the route towards resource and cost-efficient implementation.
Stephan Bruening
Schepers GmbH & Co. KG, Germany
Title: Embossing dies for surface functionalization by laser micro structuring
Time : 12:55-13:15
Biography:
Stephan Bruening is Member of the Executive Board of Schepers and responsible for R&D projects and security customer projects. He graduated in Münster and Hagen, holds an MSc degree in Photonics. During his PhD studies at the RWTH-Aachen, he worked in the area 3D-micro-structuring of metallic surfaces. In 2012, he was the winner of the Innovation Award Laser Technology of the AKL and ELI. Beside the continuous further development of the DIGILAS micro processing equipment, for e.g. intaglio printing, micro embossing, he is the R&D Manager for publicly funded projects by the BMBF, such as MICROPHOT, PIKOFLAT and currently MULTISURF.
Abstract:
The functionalization of surfaces and layers is a key technology of the 21st century. It is paving the way for the transformation of photonics into highly integrated components. In this way, traditional materials get new or improved features and new materials are developed for a resource-efficient industrial use and an increased efficiency. Virtually any structure can be written in a direct manner by only one correspondingly precise control of the laser beam. This approach is particularly well-suited to produce a so-called master which can then be used for the parallel mass reproduction of the structure, as for example for embossing plates or rollers. This second duplication step is an established process, as a disadvantage of direct laser writing is its genuine serial character, i.e., the focused laser beam is sequentially moved over all those regions of a surface where material should be removed. Embossing dies processed by ultra-short pulsed lasers are already used in some fields to transfer microstructures directly into a metal surface. One major advantage of micro structuring by ultra-short pulsed lasers is the melt-free ablation of steel surfaces of three dimensional micro structures within one step. The combination of ultra-short pulsed laser and high-precision machinery and the handling of high resolution digital file formats has been realized in the cylinder micro processing system DIGILAS for embossing dies. This contribution shows state-of-the-art structures and future possibilities of this new technology.
Jing Bai
University of Minnesota Duluth, USA
Title: Investigation on soliton related effects in mid-infrared quantum-cascade lasers
Time : 13:55-14:15
Biography:
Jing Bai is an Associate Professor and the Director of Graduate Studies (DGS) in Department of Electrical Engineering at University of Minnesota Duluth (UMD). She received her PhD degree in Electrical and Computer Engineering at Georgia Institute of Technology in 2007. His current research activities focus on nano-photonics, nano-photovoltaics, non-linear optics and nanoscale biomedical devices. Her research at UMD has been supported by the National Science Foundation (NSF), the Whiteside Institute for Clinical Research, the MN Drive Initiatives, and the Graduate School of University of Minnesota.
Abstract:
Since the first demonstration in 1994, quantum-cascade lasers (QCLs) have become one of the most important solid-state mid-infrared (MIR) coherent light sources for various applications in environment sensing, medical diagnosis and defense and free-space communication. Dynamics analysis and stable pulse progression of MIR QCLs are crucial in order for QCLs to have reliable performance in these applications. An explicit description of dynamics of QCLs is inevitably complicated when compared to conventional lasers because of the unique combination of ultrafast carrier scatterings and gain recovery, significant non-linearities and dispersion effect in a QCL medium. Discussions on dynamics in MIR QCLs have been mostly focused on the stability analysis. However, the interplay between the non-linearity and dispersion effect during the QCL coherent pulse progression has received less attention. Especially, in a nonlinear dispersive lasing medium, the combination of group-velocity dispersion (GVD) and self-phase modulation (SPM) could possibly lead to the soliton formation. A measurement of GVD in the MIR QCLs has been reported. The interaction between the GVD and the saturable absorber (SA) in the self-induced transparency (SIT) modelocking of QCLs is discussed, where the analysis is based on the evolution of electric field only and the coherence effect in the lasing transition is not included. In our current study toward the soliton formation in QCLs, we got the opportunity to carefully examine each of those two effects and analyze their interaction on the coherent pulse progression in both time-domain and frequency-domain.
Maria Chernysheva
Aston University, UK
Title: Advances in mid-infrared mode-locked fiber lasers
Time : 14:15-14:35
Biography:
Maria Chernysheva has completed her PhD from Fiber Optics Research Center of the Russian Academy of Science in 2014. Currently, she is the Marie Sklodowska-Curie Fellow at Aston University. She has an internationally recognized track record of 13 publications in high-impact factor peer review journals in the fields of rare-earth-doped mode-locked fiber lasers. The area of her research expertise include development of mode-locked lasers and pulse amplifiers; analysis of advanced saturable absorbers and their implementation; numerical modeling of higher-order soliton; dispersion managed soliton pules in passive silica and special fibers.
Abstract:
Mid-infrared light sources have become an object for wide research and industrial interest since early 2000, due to numerous of practical applications: greenhouse gases and pollutants monitoring to help climate change mitigation, high precision optical frequency standards for spectroscopy, global positioning systems (GPS) and optical clocks, LIDAR systems, and novel diagnostic techniques in medicine. All-fiber femto-second laser configuration is beneficial, since the laser fabrication process is straight forward, does not require “clean room” facilities and photolithography, and decreases the cost metric and power consumption. In my review I will start with silica Thulium and Holmium doped fiber lasers, demonstrating both ultrashort pulse durations and high output power the 1.8-2.1 μm wavelength range. However, the exceptional performance of fiber lasers cannot be extended far beyond the 2.5 μm wavelength, owing to the rapid decrease of emission intensity due to high losses in silica fibers. The fiber laser generation around 3 μm was enabled with the availability of high-purity fluoride, chalcogenide and ZBLAN glass fibers. I will review the application of these special glass matrixes to support generation at 2.75 μm in Erbium-doped fibers and at 2.85 μm in Holmium and Prazeodinium -doped optical fibers. In 2002, M.C. Downer presented pioneer work on gas-filled hollow-core fibers and announced “a new era in the nonlinear optics of gases”. Different gasses, such as acetylene and HCN, can provide gain at Mid-infrared wavelengths at low vapor pressure when pumped with nanosecond pulses. Finally I will analyze the saturable absorbers suitable for operation in Mid-infrared wavelength region.
Baldemar Ibarra-Escamilla
Instituto Nacional de AstrofÃsica, Mexico
Title: Single and dual wavelength Er:Yb double clad fiber lasers
Time : 14:35-14:55
Biography:
Baldemar Ibarra-Escamilla received the Bachelor’s degree in Electronics from the BUAP in Puebla, Mexico, in 1994. He received the MS and PhD degrees in Optics from the InstitutoNacional de Astrofísica, Optica y Electrónica (INAOE), Mexico, in 1996 and 1999, respectively. He did a Post-doctoral stay and a Sabbatical year at the Electro-Optics Graduate Program, University of Dayton, USA during 2000 and from July/2008-July/2009, respectively. He is currently a Researcher of the Optics Department at INAOE. His interests are in modelocked fiber lasers, fiber amplifiers, tunable fiber lasers, fiber sensors, high power fiber lasers and fiber optics nonlinear effects.
Abstract:
Actively Q-switched fiber lasers have been investigated due their applications in remote sensing, medicine, and terahertz generation. This technique is usually achieved to improve pulses stability and higher pulse energies. Several active Q-switched fiber laser configurations based in the use of free-space, all-fiber or fiber pigtail acousto-optic have been reported. Moreover, double-clad fibers (DCFs) are attractive as gain medium due their high conversion energy feature. Recently, we have reported an Er/Yb DCF tunable laser in continuous wave (cw) and actively Q- switched fiber laser using a fiber Bragg grating (FBG) as wavelength selective in a linear cavity resonator. The minimum pulse durations were obtained with 420 ns at a repetition rate of 120 kHz and ~0.7 W average output power in cw and 1.03 W average output power in pulsed mode. Also, we reported an actively Q-switched dual-wavelength fiber laser using an Er/Yb DCF in a linear cavity limited by a pair of FBGs in one side, and a Sagnac interferometer in the other side. We also have reported a tunable dual-wavelength actively Q-switched Er/Yb DCF laser using a polarization maintaining FBG for both generated laser wavelengths tuning. In other configuration, we reported a ring cavity dual- wavelength fiber laser with an Er/Yb DCF. By mechanical compression/stretch applied on the FBGs the laser generated wavelength maximal separation was ~4 nm. In this work, we present a review of our previous work in the area of single and dual fiber lasers.
O Pottiez
Centro de Investigaciones en Óptica, Mexico
Title: Noise-like pulse dynamics in passively mode-locked fiber lasers
Time : 14:55-15:15
Biography:
O Pottiez received his PhD from FacultéPolytechnique de Mons (Mons, Belgium) in 2001. His research interests include mode-locked fiber lasers for ultrashort pulse generation, as well as the study of non-stationary dynamics of these sources, in particular noise-like pulsing and optical rogue wave generation. He has authored or coauthored 75 publications in peer-reviewed journals and 100 international conference proceedings.
Abstract:
Due to their unique properties, noise-like pulses (NLPs) are currently attracting increasing interest for both fundamental research and applications. NLPs are chaotic bunches of optical pulses whose formation corresponds to a not-so-stable mode of operation of passively mode-locked fiber lasers. Due to their extremely complex fine structure dynamics, NLPs constitute an ideal benchmark for the study of extreme events known as optical rogue waves. On the other hand, their high pulse energy, wide bandwidth and short coherence time makes them attractive for applications including nonlinear frequency conversion, supercontinuum generation, materials processing and sensing. However, their puzzling dynamics and the difficulty to characterize them precisely make their study extremely challenging. During this talk we will present some recent advances of our group in the study of NLP generation in the 1500 nm region. Different fiber laser architectures will be considered. Record single pulse energies of 0.3 ïJ (~1000 times the energy of a conservative soliton) and spectral bandwidths of several hundreds of nm (~10 times the doped fiber bandwidth) are reported. Besides, using an original measurement technique, we retrieve information on the intimate inner structure of NLPs and confirm their connection with optical rogue waves. We also report the observation of a series of very intriguing NLP dynamics which bears some analogy with the soliton rain dynamics.
Belkacem Meziane
Université d’Artois, France
Title: Predicting the unpredictable with an isomorphic single-control parameter structure of the Laser-Lorenz equations
Time : 15:15-15:35
Biography:
Belkacem Meziane received the MS degree in Electrical Engineering (1978) from the Florida Institute of Technology, Melbourne, USA, the PhD degree (1992) and the “Habilitation à Diriger des Recherches” (1996) from ENSSAT, Université de Rennes I, Lannion, France. From 1979 to 1990, he was a Lecturer at the Algiers-University Physics Department (USTHB), Algeria. From 1990 to 1998, he was a member of the Optronics Division at ENSSAT. In 1999, he’s been a tenured Professor at the Faculty of Sciences, Université d’Artois, Lens, France. He is the author of over 30 published papers, including 2 book chapters on laser dynamics
Abstract:
Leaning on the extraction of, so far unidentified, recurrent-properties, we put forward an isomorphic structure that converts the Laser-Lorenz equations, whose dynamic solutions are usually described in terms of three independent factors, into a single control-parameter system. Such an isomorphism is shown to bring an intrinsic simplification that offers much better depictions of the Laser non-linear dynamics, while it allows for quicker and forthright inspection of the control-parameter domains, inside which well-defined periodic, symmetric and asymmetric, as well as chaotic solutions occur. The single control-parameter equations will be demonstrated to contain the full nonlinear dynamics of the original set. Functional graphical-representations, with respect to this lone control-parameter, will be shown to depict the complete hierarchy of typical windows, each bearing specific solutions. The objectives of the presentation are threefold. The primary one is to demonstrate, for the first time, that the solutions of the single mode Laser equations possess some repeatedly organized and systematic properties that allow for straightforward identification of its periodic windows, asymmetric and chaotic solutions, following some judicious arrangements of its control-parameters. Based on such endorsement, a second step will naturally end-result to transforming the equations into a single control-parameter set which encloses the same abundant dynamical solutions while preserving the full hierarchies and features of the three-control-parameter system. As a final concern, a summarizing generic map will sum up the predicted solution-windows associated with the single control-parameter variable. Hopefully, such a noteworthy simplification will render non-linear Laser dynamics much easier to apprehend.
Guofei An
Southwest Institute of Technical Physics, China
Title: Optimization of a DPAL system by adjusting cell structural parameters and cell temperatures
Time : 15:35-15:55
Biography:
Guofei An received his Bachelor’s degree in Applied Physics at Northwest Polytechnical University and has completed his PhD in Condensed Matter Physics from Northwest Polytechnical University in China at 2014. After obtaining his PhD, he worked as a research fellow of Laser Engineering in the Southwest Institute of Technical Physics. His scientific interests are in the area of laser kinetics, quantum electronics, nano-laser, and heat transfer in laser cavity. He has published more than 30 papers in scientific journals since 2010. Currently, he is mainly engaged in the research on the diode-pumped alkali vapor laser including both theoretical modeling and experiment.
Abstract:
In recent years, a diode-pumped alkali laser (DPAL) has provided the significant promise for high-powered applications. A series of models have been established to analyze the DPAL’s kinetic process and most of them were based on the algorithms in which only the ideal 3-level system was considered. However, alkalis are the most easily ionized atomic species, especially for Rb and Cs. under the condition of strong pumping the electrons will be excited to the higher levels, 62D5/2,3/2 and 82S1/2, by energy pooling collisions. Then, further ionization processes including photo-ionization and Penning ionization will occur on the 62D5/2,3/2 and 82S1/2 levels resulting in decrease of the density of neutral atoms. To examine the kinetic processes of the gas-state media, a mathematical model is developed taking into account the process of normal transition, energy pooling, and ionization. The procedures of heat transfer and laser kinetics were combined together in our theoretical model. We systemically investigated the influences of the temperature, cell length, and cell radius on the output features of a DPAL. By optimizing these key factors, the optical-to-optical conversion efficiency of a DPAL can be evidently improved. Further, the calculated results indicate that the influence of energy pooling and ionization can be obviously suppressed with the optimal parameters. In the case of high pump power, 1000 W, the influence of energy pooling and ionization on output power decreases from 6.02% to 1.04% and the optical-to-optical efficiency increases from 16.5% to 51.5% after optimizing. Basically, some conclusions we obtained here can be extended to any other kinds of end-pumped laser configurations.
- Workshop
Location: July 28, 2016- Embassy I+II
Chair
Sergei A Kozlov
ITMO University, Russia
Co-Chair
Sergey A Moiseev
Kazan National Research Technical University, Russia
Session Introduction
Aleksey Mickhailovich Polubotko
Saint Petersburg State University, Russia
Title: Strong quadrupole light-molecule interaction and surface-enhanced optical processes
Time : WS01
Biography:
Aleksey Mickhailovich Polubotko graduated from Physical Faculty of Leningrad State University in 1973. He completed his PhD in A F Ioffe PhysiÑo-Technical Institute Russian Academy of Sciences and defended the PhD thesis in Azerbaijan Institute of Physics in Baku in 1983. Currently, he works as a Physicist Theorist and a Senior Scientific Researcher of the sector of Semi-conductors and Dielectrics of the Department of Dielectrics and Semiconductors of A F Ioffe Physico-Technical Institute in Saint Petersburg. He has more than 120 scientific papers, preprints and abstracts published in reputed journals and reported in many scientific conferences.
Abstract:
Surface-Enhanced Optical Processes, SERS, SEHRS and SEIRA are of great interest for physics, chemistry and biology since they all allow increasing strongly the sensitivity of these spectroscopic methods and there is a fundamental physical mechanism, which causes the enhancement in these processes. It is so-called strong quadrupole light-molecule interaction, arising in surface electromagnetic fields, strongly varying in space near a rough metal surface. Just this interaction is responsible for the enhancement in SERS 106, in SEIRA 103 -104 and in SEHRS 1012 and significantly higher. Moreover, this interaction is the base for implementation of Single Molecule Detection by SERS, when the enhancement can achieve the value 1014 -1015. This interaction is responsible for appearance of forbidden lines in all these processes on molecules with sufficiently high symmetry. Indeed, these strong lines were observed in ethylene and diprotonated in SEIRA and in pyrazine and phenazine in SEHRS. They are the lines, caused by vibrations with the unit irreducible representation of a molecule symmetry group. Such strong lines are observed in SERS as well. However, they are caused by vibrations with the irreducible representations, which describe transformational properties of the dipole moment component , which is perpendicular to the metal surface. At present the theory of the above mentioned processes, based on this concept is created and explains the most of the observed phenomena, accompanying SERS, SEHRS and SEIRA.
Sergei A Kozlov
ITMO University, Russia
Title: Polarization-independent subcarrier quantum communication system and its application in ITMO University quantum network
Time : WS02
Biography:
TBA
Abstract:
A quantum key distribution system based on the subcarrier wave modulation method has been demonstrated which employs the BB84 protocol with a strong reference to generate secure bits at a rate of 16.5 kbit/s with an error of 0.5% over an optical channel of 10 dB loss, and 18 bits/s with an error of 0.75% over 25 dB of channel loss. To the best of our knowledge, these results represent the highest channel loss reported for secure quantum key distribution using the subcarrier wave approach. A passive unidirectional scheme has been used to compensate for the polarization dependence of the phase modulators in the receiver module, which resulted in a high visibility of 98.8%. The system is thus fully insensitive to polarization fluctuations and robust to environmental changes, making the approach promising for use in optical telecommunication networks. Further improvements in secure key rate and transmission distance can be achieved by implementing the decoy states protocol or by optimizing the mean photon number used in line with experimental parameters. The system was used in deployment of ITMO University quantum network in Saint Petersburg, Russia, where a polarization independent subcarrier wave quantum key distribution operation with sifted bitrate 250 kbit/s was for the first time demonstrated in metropolitan telecommunication network channel composed of standard SMF-28e fibers with 1.5 dB loss.
Aleksey Mickhailovich Polubotko
Kazan National Research Technical University, Russia
Title: Electrodynamical forbiddance of the strong quadrupole light-molecule interaction and its manifestation in fullerene C60
Time : WS03
Biography:
Aleksey Mickhailovich Polubotko graduated from Physical faculty of Leningrad State University in 1973. He completed his PhD in A.F. Ioffe PhysiÑo-Technical Institute Russian Academy of Sciences and defended the PhD thesis in Azerbaijan Institute of Physics in Baku in 1983. Currently, he works as a physicist theorist and a senior scientific researcher of the sector of semi-conductors and Dielectrics of the Department of Dielectrics and Semiconductors of A F 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 scientific conferences.
Abstract:
At present it is well proved in our works that the reason of SERS, SEHRS and SEIRA is so-called strong quadrupole light-molecule interaction, which arises in surface electromagnetic fields strongly varying in space near a rough metal surface. This interaction is associated with terms of the light-molecule interaction Hamiltonian with the quadrupole moments and , or their linear combinations transforming after the unit irreducible representation of the molecule symmetry group, which results in appearance of strong forbidden lines in molecules with sufficiently high symmetry. The general requirement for observation of these lines is belonging of the molecule to the symmetry group, where the component of the dipole moment , which is perpendicular to the surface transforms after the irreducible representation another, than the unit one. However, it appears that for the molecules, which belong to the cubic symmetry groups and the icosahedral groups and the strong quadruple light-molecule interaction, is forbidden due to specificity of these groups and the electrodynamic law. Therefore, the light-molecule interaction in these molecules is of a purely dipole type. This property must result in the absence of the lines with the unit irreducible representation in the SEIRA and SEHRS spectra of molecules, belonging to these groups. The absence of the indicated lines at 496 and 1470 was observed in fullerene that strongly supports the Dipole-Quadrupole theory of the indicated processes.
Artur V. Gleim
ITMO University, Russia
Title: Polarization-independent subcarrier quantum communication system and its application in ITMO University quantum network
Time : WS04
Biography:
TBA
Abstract:
A quantum key distribution system based on the subcarrier wave modulation method has been demonstrated which employs the BB84 protocol with a strong reference to generate secure bits at a rate of 16.5 kbit/s with an error of 0.5% over an optical channel of 10 dB loss, and 18 bits/s with an error of 0.75% over 25 dB of channel loss. To the best of our knowledge, these results represent the highest channel loss reported for secure quantum key distribution using the subcarrier wave approach. A passive unidirectional scheme has been used to compensate for the polarization dependence of the phase modulators in the receiver module, which resulted in a high visibility of 98.8%. The system is thus fully insensitive to polarization fluctuations and robust to environmental changes, making the approach promising for use in optical telecommunication networks. Further improvements in secure key rate and transmission distance can be achieved by implementing the decoy states protocol or by optimizing the mean photon number used in line with experimental parameters. The system was used in deployment of ITMO University quantum network in Saint Petersburg, Russia, where a polarization independent subcarrier wave quantum key distribution operation with sifted bitrate 250 kbit/s was for the first time demonstrated in metropolitan telecommunication network channel composed of standard SMF-28e fibers with 1.5 dB loss.
Vladimir Egorov
Saint Petersburg State University, Russia
Title: Maintaining security against photon-number-splitting attacks in subcarrier wave quantum communication systems
Time : WS05
Biography:
Vladimir Egorov has completed his PhD studies in Optics at ITMO University in 2015. He has published more than 15 papers in peer reviewed journals. His research interests include quantum communications and networking, nanophotonics and plasmonics.
Abstract:
Subcarrier wave (SCW) approach to quantum communication systems demonstrates many promising capabilities for establishing multiuser quantum networks. In this type of systems the quantum signal is obtained at spectral sidebands in course of phase modulation of light at the central frequency emitted by the source. All current SCW experiments use laser radiation for generating the light at central frequency, and its subsequent modulation and attenuation for creating the sidebands. Therefore, the photon number statistics in the quantum channel is described by the Poisson distribution, and countermeasures against photon-number-splitting (PNS) attack are in order. Differences in SCW architecture from other types of quantum communication systems require developing special techniques for maintaining security against PNS. For the widely-employed decoy states method, one must ensure that the eavesdropper cannot identify the decoys by monitoring the fluctuations of intensity of light at the central frequency. To solve this problem, we propose a novel experimental scheme of the SCW transmitter module. The “strong reference” protocol especially proposed as an alternative to the decoy method in SCW, establishes certain bounds on the filtering subsystem in the receiver module. We calculate the optimal parameters of the source, detector and filter in the system in order to find an effective trade-off between them. Finally, we developed a novel method of maintaining security against PNS by analyzing the counting statistics using a photon-number-resolving detector. We compare the system architectures from engineering point of view and calculate key generation rates for these protocols, defining optimal solutions for different channel losses.
E N Kotlikov
Saint Petersburg State University of Aerospace Instrumentation, Russia
Title: Method for determining of the optical constants for films and materials inside the absorption bands region
Time : WS06
Biography:
TBA
Abstract:
Spectrophotometric methods are most commonly used for determining of the optical constants of films and materials are. These methods are based on measuring of the reflection R (λ), transmission T (λ) and absorption A (ï¬ï€©ï€ spectra and make it possible to obtain the dispersion characteristics of the optical constants throughout the required range of the spectrum. The principal difficulties arise at the stage of analysis of the spectra, and obtaining from them the information about optical constants, particularly in the absorption bands regions. In terms of mathematical methods of spectra processing, methods of determining of the optical constants can be divided into two sets: analytical and numerical. The first set involves the search for suitable analytical expressions for the direct calculation of optical constants in various specific cases. The second one is based on numerical methods for finding the minimum of functional of quality. Currently there is no single universal method for determining the optical parameters of of real films and materials from the spectrophotometric data. It is caused by incorrectness and the ambiguity in determining the optical constants from the spectra. We propose a new method based on the correction of measured spectra taking into account the absorption. After this correction, the absorption becomes zero and one variable - the absorption coefficient is excluded from the calculation, which greatly simplifies finding of the optical constants. The main idea of the proposed method is based on the additivity of energy conservation law, which can be presented as 1=T(λ)+R(λ)+A(ï¬ï€©. Absorption may be divided into two parts: A (ï¬ï€©=AT +AR, where AT and AR defines the absorption contribution to the transmission and reflection spectra. To find the AR (ï¬) and AT(ï¬), we use the correction functions fr and ft which define the contribution of total absorption A(ï¬ï€© into AR(ï¬) and AT(ï¬). Correction functions fr and fl are calculated using the approximate absorption spectrum A(ï¬ï€©ï€® Spectra without absorption are defined as: T0(λ)=T(λ)+ftÐ(ï¬ï€©ï€¬ï€ ï€ R0(λ)=R(λ)+ fRÐ(ï¬ï€©ï€¬ where all the values in the right-hand sides are known. It is important to note that the dispersion of the refractive index in the spectra of T0 (λ) and R0 (λ) remains unchanged. The absorption coefficient ï¡ can be found from the spectra by known methods. By this method we have determined the optical constants of the thin films BaF2, Ba0.98Mg0.02F2, CaF2, CaYF5 and various materials of the transmissive optics in the absorption bands region in the middle IR spectral range.
Andrei Gaidash
ITMO University, Russia
Title: Proof of standard security analysis compatibility with a sub-carrier wave quantum communication method
Time : WS07
Biography:
Andrei Gaidash recieved two MS degrees in Photonics and Optical Information Technologies at ITMO University (Russia) and University of Rochester (USA) in 2015. He is currently a first year Post-graduate student at ITMO University. His research interests include quantum information and communication technologies.
Abstract:
The field of quantum communication and key distribution (QKD) is reaching its maturity, opening the door to commercially available systems and quantum networks. For secure optical networking applications, the sub-carrier wave (SCW) QKD systems demonstrate some important advantages, in particular high spectral efficiency, polarization independence, and unidirectionality. However, currently there is no strict proof of security presented for this class of QKD systems due to an uncommon way of generating the quantum signal in them. In SCW systems, phase modulation of a high-intensity signal produces the quantum signal at its spectral sidebands. We investigate the properties of quantum signals in a SCW system using the theory of electro-optical modulators in order to prove that the standard security analysis can be applied. We consider both classical and two quantum approaches: with finite and infinite number of interacting modes. We discuss how to estimate the number of interacting modes and how a finite number of them affects on the modulation process. Knowing how the quantum states develop due to modulation, we derive an equation for quantum interpretation of the second order correlation function for both sidebands. We then demonstrate that the second order correlation function equals unity, and thus both sidebands can be interpreted as one coherent state with double mean photon number compared to one sideband. Therefore, we for the first time demonstrate that the quantum channel in the SCW system satisfies the conditions of the standard (for example, Inamori-Lutkenhaus-Mayers or Gottesman-Lo-Lutkenhaus-Preskill) security analysis for QKD with coherent states source.
Kozubov Anton
ITMO University, Russia
Title: Linear optical quantum circuits construction algorithm based on directed graphs or transform matrices
Time : WS08
Biography:
Anton Kozubov has received his Bachelor’s degree at the ITMO University in 2015 and is at present in his first year of Master’s program. He works as an engineer in quantum information laboratory at ITMO University. His scientific areas of interest include quantum computing and communications.
Abstract:
Today great interest in quantum information is observed throughout the world. Quantum computing schemes based on quantum algorithms will allow for effectively solving many complicated mathematical problems. There are two different approaches to implementing the experimental schemes for quantum algorithms: based on linear (LOQC) or quantum circuits with nonlinear elements. The LOQC schemes are easier to implement, but their mayor disadvantage lies in probabilistic nature of their functioning. The probabilistic nature of obtaining results in the LOQC supports the relevance of the search of the most effective variants of optical circuit designs for specific quantum operations: their composition and arrangement of the basic quantum computing elements. In this report we propose an algorithm for automatically constructing LOQCs from several basic elements. The program uses the transformation matrix, relating the input and output parameters of the quantum system, or a directed graph that describes the composition of the desired circuit. The algorithm is based on the method of dual-rail encoding. In our implementation, beam splitters and wave plates are used as the basic elements. These basic elements are required for optical realization of any one- or two-qubit gates. As a result of this work, we developed an algorithm that allows implementing LOQC using the transformation matrix between the input and output states, or a directed graph. Additionally, the programs allow analyzing the circuit relative error probability, and choose the best possible realization.
Dmitrii Pankin
St. Petersburg State University, Russia
Title: Investigation of process of quartz glass crystallization by confocal Raman spectroscopy
Time : WS09
Biography:
Dmitrii Pankin has completed his Master's thesis. Currently, he is a PhD student at Saint Petersburg State University on physical faculty.
Abstract:
In our work, industrial type glass for UV (KU-1 quartz glass (QG)), visible (KV QG) and IR (KI QG) regions have been choosed. Sizes of samples are 40x40x5 mm. It’s working surface had been polished by CeO2 and after that heating was performed. In region 1100-1300°C stability of temperature was maintained at ± 2°Ð¡. Heating was conducted during 10 hours. Visual observations of working surface has shown growth of crystallization regions (CRs) with typical in-plane dimensions of tens of microns. Nevertheless indepth dimension can reach about 100 microns. Shapes of CRs varies with type and concentration of impurities that are present in the type of glass. Most different shapes of CRs were observed in KV because of high concentration of impurities and OH bonds comparing to that in other samples. Mostly shapes of CRs in other samples has radial symmetry. It was due to begin of crystallization near impurity metal ion such as Al3+, Ca2+, Na+, Mg2+, Mn2+ or Fe2+. This ions substitute Si4+ in SiO2 tetrahedra or embedded between them. Investigation of early stages crystallization in industrial type quartz were performed by confocal Raman spectroscopy techniques. By 2D mapping and in-depth confocal measurement it was shown that crystalline region is made up of crystallization center, intermediate layer and thin bound. Intermediate layer is made up of α-SiO2 quartz nanoparticles with diameter more than 20 nm. According to Raman spectra and our calculations thin bound is made up of α-SiO2 nanoparticles with diameter 2-8 nm coagulated with Fe2O3, Fe3O4, TiO2 and SiC. Such coagulation enhance multiphonon processes in Raman scattering of crystalline quartz.