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

Shien-Kuei Liaw received double doctorate degrees in photonics engineering from National Chiao-Tung University in 1999, and in mechanical engineering from National Taiwan University in 2014, respectively. He joined the Chunghua Telecommunication, Taiwan, in 1993. Since then, he has been working on optics communication and fiber based devices. He was a visiting researcher at Bellcore (now Telcordia), US for six months in 1996 and a visiting Professor at University of Oxford, UK in autumn 2011. Currently, he is a distinguished Professor at National Taiwan University of Science and Technology (NTUST). He has been awarded about 37 patents and has published 240 journal articles and international conference presentations. He has been actively contributing for various conferences as program chair, organizing committee chair, session chair and invited speaker. His research interests are in optical sensing, optical communication, fiber optics and reliability testing. Prof. Liaw is a senior member of IEEE, OSA ans SPIE. rn

In this talk, we will review and discuss Ytterbium doped fiber laser in 1064 nm band. For linear-cavity fiber laser schemes, the elements may base on a loopback optical circulator (OC), a broadband fiber mirror, a Faraday rotator mirror or a 2x2 fiber coupler integrated a partial reflectance fiber Bragg grating (FBG) as the front cavity end. For single-longitudinal mode (SLM) selection, using multiple subring cavities based on the Vernier effect, a piece of gain fiber saturable absorber as modes filter or their hybrid type. For wide-tuning range fiber laser, the wavelength tuning mechanism include the use of a broadband fiber mirror (BFM) integrated tunable FBGs as cavity ends, using a 3-point bending device, using a four-lamina composite device to facilitate wavelength tuning of FBGs, a large tuning range cover 1064 nm band with good resolution of 0.1 nm is obtained. Laser characteristics such as output, signal-to-noise ratio, linewidth, threshold pump power, pumping slope efficiency and side mode suppress ratio are measured. The pumping power efficiency may be improved more than 10% by recycling the residual pump power to the gain medium. With the advantages of simple structure, large pump slope efficiency and short cavity, the Ytterbium doped fiber laser may find potential applications in various ways.

K.A.Trukhanov is doctor of technical science (the radiation and electromagnetic safety at space, 2006). He is the principal researher of Institute of Biomedical Problems RAS. He has published more than 25 papers in reputed journals.

Cherenkov radiation (CHR) occurs when velocities of charged particles in a medium exceed the phase velocity of light in it.rnI. M. Frank (Nobel laureate together with P. A. Cherenkov and I. E. Tamm) once remarked: CHR radiators were the first macroscopic coherent emitters.rnThe report provides a method of finding the velocity distribution of particles (VDP) in accelerator’s beams. VDP is obtained from the solution of the Volterra integral equation of the first kind of the convolution type. The right-hand side of this equation presents a nonlinear part of the experimental dependence of CHR intensity on refractive index magnitudes for the given beam. VDP is the second derivative of this dependence on the inverse value of \"n\". The solution is stable when at taking into account a priori information about its properties.rnThe usage of radiators with an optical dispersion is discussed. The dispersion hampers the use of Cherenkov methods somewhat but here it turns into a \"friendly phenomenon\" which may serve to determine VDP even in single bunch of particles. The possibility of finding VDP with the help of holographic methods for rapid processing of information is discussed. The determination of VDP distribution over the beam cross section is analyzed. The determination of VDP is possible also at a case of beams with non-zero transverse particle velocities. The proposed method is particularly useful when the VDP is narrow which is typical for high energy beams. Essentially the method is non-destructive in most applications.rn

Okayama has awarded his PhD at the age of 35 years from Waseda University. He is the senior researcher at R&D center, OKI.. He has published more than 100 papers in journals and conference proceedings.

We describe the waveguide optical deflector using a Y-shaped waveguide coupled to a slab waveguide via gaps between them. An electrode is placed on each arm of the Y-shaped waveguide to control the refractive index. The device can be used in many applications, such as optical switch, printing and imaging.rnThe input light is devided to the two arms of the Y-shaped waveguide. The light propagated in the Y-shaped waveguide is coupled to the light in the slab waveguide through evanescent field. Two lights generated by evanescent field coupling form a narrow collimated light beam in the slab waveguide, which direction can be steered by changing the refractive index using electrodes. Simple low-capacitance stripe electrodes may enable a fast deflection. A symmetrical light beam with low side lobes is generated by a simple structure. We designed a device for semiconductor material. BPM simulation shows a deflection angle of 2o at a push-pull refractive index change of around n/n =3x10-3. A extinction of side lobe lower than -13 dB is attained.rn

Gennady Valentinovich Golubkov, Professor, Doctor of Physical and Mathematical Science, Leading scientist of Semenov Institute of Chemical Physics, Russian Academy of Sciences, Specialist on the quantum scattering theory, the theory of atom-molecular processes and elementary chemical reactions, chemical physics of atmosphere and low temperature plasma

The impact of solar activity on the atmosphere has been intensively studied in the United States, Japan, India, China, Australia, Brazil and the leading European countries. It is caused by continuing attempts to establish the nature of sporadic disorders of the global satellite positioning system work. In the N.N. Semenov Institute of Chemical Physics (Moscow, Russia) on the basis of a detailed analysis of series of experiments conducted at the Cornell University (USA) and in other research centers, has been found a direct link between the UHF incoherent radiation power of the D and E layers of the atmosphere in the decimeter range with the positioning errors. This radiation is due to transitions between the split reaction with a neutral medium characterized by the orbital degenerate Rydberg states, living in a two-temperature recombination plasma. A large number of experimental data on S/N ratio of power and delay of the received GPS signals enabled to create a theory of the ultrahigh-frequency (UHF) signal propagation through the upper atmosphere. This theoretical problem is reduced to the study of the process dynamics and the calculation of intensity and shape of the emission lines. The data are put into the general kinetic scheme establishing a time dependence of the Rydberg particle concentration distribution on height as functions from density, flow of electrons and temperature, composition and temperature of the atmosphere. The obtained results compose an essential component of radio-chemical physics of the Earth\'s atmosphere as a science on interaction of electromagnetic waves with the resonance quantum medium containing Rydberg molecular complexes that occur in the upper atmosphere (at altitudes of 80-110 km) and are responsible for the delay of satellite constellation signals. The radiative transitions between their states form the additional background incoherent UHF and longwave infrared (IR) radiation that plays an important role in basic research and uses independently in many scientific and technical applications. These studies will allow to determine the plasma parameters and the characteristic times of the satellite signals propagation delay at different carrier frequencies simultaneously, i.e. in the same physical conditions. Such data are necessary for effective employment of positioning system as measurement devices.

Dr. Kolokolov has completed his PhD from Lomonosov Moscow State University and postdoctoral studies at NASA Ames Research Center. He is a research scientist at Lomonosov Moscow State University and developer of the Heterostructure Design Studio software. He has published more than 33 papers in reputed journals.

We performed a set of experiments and numerical calculations on strained p AlxGa1 xAs/GaAs1 yPy/n AlxGa1 xAs heterostructures under uniaxial stress. These structures are widly used in commercial laser diodes emitting at 766 – 808 nm. The results show that polarization of emitted light can be extremely sensitive to external uniaxial stress due to the change of wave functions and optical transitions between the subband levels in the quantum well. The increase of applied uniaxial compression leads to the strong change of the energy spectrum of light (LH) and heavy (HH) holes. At zero external compression the uppermost level h1 is a pure LH state and the next level h2 is a pure HH state. While the compression increases the HH state is admixed to LH one. Finally the share of HH state becomes dominated on level h1. So the topmost level h1 becomes almost of HH nature. These changes in the topmost state of the QW removes the prohibition on the interband transitions to occure only in the TM mode. The results of calculations for the experimentally investigated structure demonstrates that in the 14 nm quantum well with phosphor fraction of 0.16 the ratio gTM/gTE of optical gain in the TM and TE modes at zero compression is equals to 8. Under compression P = 5.1 kbar in [110] direction the gTM/gTE ratio strongly drops to 1.6 that is in a good agreement with the experimental data with about 5% of variance.