This PDF file contains the front matter associated with SPIE Proceedings Volume 7822, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

A coherent fiber laser array in a Self-Fourier cavity is described. The Self-Fourier cavity has been shown to coherently combine an array of fiber lasers through its ideal supermode discrimination as a result of its passive coupling matrix of rank 1. Recently, a static model has been developed that extrapolates this technique to an array of very large number of fiber lasers by exploiting the gain-dependent phase shift and incorporating specific levels of individual feedback to each fiber amplifiers, transforming them into regenerative amplifiers. By engineering the resonator in the manner described here, this enables us to circumvent predicted scaling limits and offers the possibility to achieve a highly phased state for a large number of fiber lasers in such an array. Experimental results are presented, the model of operation is discussed, and scaling predictions are presented.

Self-organized coherent laser array seems to be a promising method for coherent combining fiber lasers. Phase locking is realized by mutual energy injection, without any active phase stabilization, requirement of the fiber length or the output power for individual lasers. In this paper, a novel self-organized coherent combination configuration of an array of fiber lasers has been demonstrated. Mutual injection locking and coherent combining of three and four individual erbium-doped fiber lasers have been reported.The fiber lasers are mutually injected by couplers. Under free running state, the far field beam profile is a simple intensity superposition as incoherent beams, under mutual injection locking, good coherence has been obtained in the far field of the fiber laser arrays. This scheme is quite easy to implement and can be extended to combine more beams.

The application of a Nonlinear Amplifying Loop Mirror (NALM) as a nonlinear phase-shift compensator (NPSC) in phase-shift keyed transmission is investigated with emphasis on Differential Quadrature Phase-Shift Keying (DQPSK). The origin of the effective negative nonlinear phase shift in a NALM and the effects of the NALM parameters on the phase-shift compensation are discussed. Two possible application modes of the NALM as NPSC have been found: sole nonlinear phase-shift compensation up to 3 rad, and phase-shift compensation in a smaller range with simultaneous amplitude equalization. The points of operation for both modes and the limitations in their implementation are presented. Results show that the use of a NALM, optimized for phase-shift compensation, seems to be very promising, especially for the application as post-compensator in differential phase-shift-keyed transmission systems. To evaluate the performance of a NALM as post-compensator a simplified model of the NALM and a DQPSK transmission system was used. The BER with and without the NALM was calculated in dependence on the average nonlinear phase shift and on the input noise. The results show that with a NALM as NPSC the amount of nonlinear phase shift in a preceding transmission system can be approximately doubled for the same BER.

We present a model for Q-switched, double cladding Yb-doped fiber laser. We investigate the effect of length of fiber and repetition rate of acousto-optic modulator on the duration and energy of the fiber laser pulse. Our modeling shows that by increasing of the fiber laser length the shape of pulse change and energy increase. And also by increasing the repetition rate frequency the energy of pulses decreases.

Different schematic designs of Q-Switch Drivers for Pockels Cell based optical arrangement are considered. Schematic solutions of Q-Switch driver design are analyzed. Marx Bank based Generator and High Voltage Switch Schematics are compared. Parameters of constructed Q-Switch Drivers are presented.

Parameters of Raman eye-safe laser for serial range-finder are determining by request of range and pumping energy. The basic parameters of laser resonator are reflection coefficient of mirrors and residual reflection coefficient of active element (KGW:Nd), and initial transmission coefficient of passive Q-switcher making by crystal YAG:V with big saturation anisotropy. The correct choosing of all this parameters is very important for optimal lasing.

We report the development of a nanoimprint lithography patterning method and inductively coupled plasma etching recipe designed for GaSb-based semiconductor materials. The developed processes were used to fabricate edge-emitting ridge-waveguide lasers and laterally-coupled distributed feedback lasers operating at 1945 nm. For ridge-waveguide laser with 1 mm cavity length, a threshold current of 32 mA was measured. Side-mode suppression ratio in excess of 30 dB was measured for the distributed feedback lasers with 2 mW output power and the output wavelength was temperature-tunable with a tuning coefficient of 0.16 nm /°C.

The concept of multiple gain element cavity was applied for power scaling a passively mode-locked semiconductor disk laser. 400 mW of average output power for the laser with a single gain element was boosted to 900 mW for the laser with the dual gain cavity. The increase in output power was accompanied by an increase in the order of mode-locking harmonic.

Coupled wave equation group of surface acoustic wave (SAW) acousto-electro-optic (AEO) effect are given and correlative conversion efficiency formula is obtained. An collinear SAW AEO modulator with xy-cut lithium niobate (LN) substrate is made. Curves of relative conversion efficiency vs electric power, direct current (dc) voltage and frequency are measured. Additional dc voltages can change the center frequency of the modulator. This device has applications in optic signal processing and optic communication.

The paper describes an experimental method of determining probability density distribution for random threshold values of laser fluence, damaging surface of optical components. The method is as follows. Numerous surface sites of an optical component have been irradiated by a laser beam with a known non-uniform fluence distribution and magnitude sufficient for surface damage. Subsequently, the minimal fluence value ε has beens determined at the boundary of the damaged zone for each irradiation spot. It is shown that the sampling of minimal damage threshold values obtained from the above-described data assembly makes it possible to construct the probability density distribution f(ε). Knowledge of this distribution provides for the use of order statistics in damage threshold fluence data analysis and, thus, enhances accuracy and reliability of determination of surface strength for sizable optic components tested by small-diameter beams.

The optical attachment for transformation the spatial characteristics of excimer laser has been experimentally investigated. The laser beam of rectangular section with sizes of 3 x 20 mm and divergence of 2 x 5 mrad after passage of an optical attachment got the square form 20 x 20 mm and equal divergence of 5 x 5 mrad orthogonal directions. It is shown, that application of such unit in the facilities for microprocessing of materials simplifies an optical path of illumination module, allows to receive the optimum uniformity of irradiation (within 2 %) at reproductive image with micron accuracy in plane of processed material and to mitigate the beam load on optical elements due to suppression of influence of "hot" points.

Double reducing threshold of laser oscillation between two crystals of equal geometry (3x3x10 mm3) and different pump absorption (80 and 50 %, correspondingly) was observed. For both cases the value of slope efficiency was nearly 22%. The lowest threshold of absorbed pump power 360 mW with 2% OC was measured for series crystals with small pump absorption. The focusing of pump beam was no tight (waist radius 38 mm) in comparison with similar experiments with forsterite crystals.

Self-focusing and defocusing of optical radiation with Gaussian spatial and temporal distribution due to cascading SHG without significant changing of beam profile and pulse shape for fundamental wave under the condition of group velocity in the axial-symmetric case for bulk medium is considered. We show the possibility of strong self-focusing of optical radiation: maximum intensity increases in 70 and more times in comparison with intensity of incident optical radiation. These results are obtained for pulse duration, which belongs to time interval from microseconds to picoseconds, for which dispersions of group velocity are negligible. A propagation of laser radiation without changing of its pulse shape and beam profile takes place till the formation of the first nonlinear focus. Spatio-temporal intensity distribution near the other nonlinear focus can be strongly distinguished from Gaussian one. For corresponding choice of mismatching of wave vectors the losses of energy at fundamental wave because of its conversion to the wave with doubling frequency is less than 1%. Self-focusing of laser radiation allows the possibility for realization of the regime which is similar to Kerr-lens mode locking, but for laser systems generating optical radiation with duration from microsecond to picosecond duration.

A new method of high-effective generation of Bessel vortices from zero-order Bessel beam in one-dimensional photonic crystal is proposed and elaborated. The influence of parameters of the structure and incident beam on this process is analyzed.

In the neighborhood of the cusp of the "double" caustic produced by the y- polarized convergent eo- and ee- beams, a single isolated optical vortex was found to exist. The observed single vortices are formed only under four strictly defined angular orientations of the incident collimated light beam relative to the entrance face of two-component crystal-optics element (TCE). As the direction of propagation of a collimated laser beam striking normally the TCE is reversed, a distinct localized quadrupole optical vortex consisting of four closely spaced vortices with pairwise-opposite topological charges -1, +1, +1, and -1 forms close to the cusp of this caustic (diffraction catastrophe). The analysis of quadrupole vortex formed by TCE was done for comparative purpose because both vortex fields are formed near the corresponding paraxial foci by the same crystal-optical element.

We have discovered that if input grating coupler is used to excite SEW the generated wave is differed essentially from SEW. This wave is conventionally named "pressed wave" by us. We examine the evolution of wave field with distance from input grating coupler and compare that with analogous dependence for SEW. It is shown that unlike SEW the intensity of pressed wave decreases not exponentially while it propagates along the surface. Also we have got that the pressed wave field profile is modified as it propagates along the surface.

The linear canonical transform(LCT) is a parameterized linear integral transform, which is the general case of many well-known transforms such as the Fourier transform(FT), the fractional Fourier transform(FRT) and the Fresnel transform(FST). These integral transforms are of great importance in wave propagation problems because they are the solutions of the wave equation under a variety of circumstances. In optics, the LCT can be used to model paraxial free space propagation and other quadratic phase systems such as lens and graded-index media. A number of algorithms have been presented to fast compute the LCT. When they are used to compute the LCT, the sampling period in the transform domain is dependent on that in the signal domain. This drawback limits their applicability in some cases such as color digital holography. In this paper, a Fast-Fourier-Transform-based Direct Integration algorithm(FFT-DI) for the LCT is presented. The FFT-DI is a fast computational method of the Direct Integration(DI) for the LCT. It removes the dependency of the sampling period in the transform domain on that in the signal domain. Simulations and experimental results are presented to validate this idea.

The fractional Fourier transform (FRFT) is applied to a radial Gaussian beam array. Analytical formula is derived for the irradiance distribution of coherent and incoherent radial Gaussian beam array in FRFT domain using Collins integral formula. It is revealed that the irradiance pattern can be tailored to be controllable dark-hollow, flat-topped and Gaussian beam pattern by changing of the fractional order of FRFT and the coherent state of the laser array.

A new method for the crest factor minimization of for multi-tone signal based on the sampling functional is proposed. The minimum of sixth moment is used as an initial value for the minimax search. For high number of tones the optimal values are better than previously reported. Application for fiber Bragg multi-channel filters for telecommunications is discussed.

Conditions of reception of circular and elliptic radiation in results additions of two beams with not orthogonal vectors of intensity of electric fields are defined. The method of creation of light beams with the set condition of polarization is offered.

To determine an optical sign of the investigated crystal plate, a conoscopic pattern of the latter is changed in an optical system without a polarizing microscope. Unknown optical sign of the crystal plate is determined by the nature of changes made to its conoscopic pattern by the plate of known optical sign. To change the conoscopic pattern, an auxiliary plane-parallel crystal plate of arbitrary thickness and known optical sign is used. Such plate either capable of rotation about its vertical axis is introduced to the optical system.

The concept of a solar energy conversion into laser radiation on a basis of fullerene-oxygen-iodine laser (FOIL) is considered. A basis of FOIL construction is the photoexcitation of fullerene molecules into their triplet state by the sunlight, interaction of the photoexcited fullerene molecules with molecular oxygen with a singlet oxygen formation and subsequent transmission of the singlet oxygen energy to iodine atoms. Efficiency of the given process makes 30 % approximately. It is shown that for solar energy transformation to the laser radiation the singlet oxygen generator is under construction on the basis of solid-state porous fullerene-containing membranes. Results of working out and research of solid-state generators of singlet oxygen are presented. Constructive design of fullerene-oxygen-iodine laser of the continuous operating mode with the solar pumping for transformation of the sunlight to the laser beam for the decision of power problems are presented.

Nanopores are a new class of low dimensional semiconductor nanostructures which have been recently proposed for use in lasers and other photonic applications. This paper provides an overview of patterned nanopore lattices with an emphasis on their electronic and optical properties. The ability to control nanopore properties by geometry and material composition are demonstrated. Two methods for controlled nanopore fabrication are presented and compared. Spectral characteristics of nanopore lasers are presented. Finite element numerical simulations are also performed to determine the band structure and emission properties of nanopores.

The interaction of excimer laser pulses with silica consisting ion-synthesized copper nanoparticles is studied. Using optical reflectance of composite layers it is established that at the initial stage laser annealing leads to the fragmentation of the nanoparticles to smaller ones. After continuous irradiation by several pulses, the nanoparticles become larger due to the heating of the surrounding glass. The laser treatment for a longer time (more than several tens pulses) results in the dissociation of nanoparticles into small clusters and individual atoms. The mechanisms responsible for the modification of the composite material under high power laser radiation are discussed.

The employment of microstructured targets for efficient ion acceleration by short intense laser pulses is discussed. We further examine recently proposed targets, such as foil with hole or foil with slice joint to its front surface, by two dimensional particle-in-cell (PIC) simulations. These microstructured targets enable to accelerate protons to higher maximum energies compared with simple thin foils due to additional acceleration of hot electrons during laser-target interaction. On the other hand, we found that the energy fluencies of protons accelerated in those specially designed targets are reduced compared with thin foils irradiated by obliquely incident laser pulses.

A remarkable conversion efficiency from laser to protons is demonstrated by particle simulations in a laser-foil interaction. The total laser-proton conversion efficiency becomes 16.7% in an optimized multi-hole target, though a conventional plane foil target serves a low efficiency. When an intense short-pulse laser illuminates the thin foil target, the foil electrons are accelerated around the target by the intense laser. The hot electrons generate a strong electric field, which accelerates the foil protons, and the proton beam is generated. In our previous study, we found that multihole thin-foil target was efficient for the energy conversion from laser to protons [Phys. Rev. E 78, 046401 (2008)], and the energy conversion efficiency was 9.3%. In this paper the results clarify the role of the target hole thickness and depth in the laser-proton energy conversion. The optimized multi-hole foil target provides a remarkable increase in the laser-proton energy conversion efficiency.

This paper describes a specific criteria used for structural design in high stability required activity such as Inertial Confinement Fusion (ICF). The specific criteria is based on coupled motion existing in optomechanical systems. Compared to the generic criteria, compliance with the specific ones can guarantee an equally good structural stability and relax the requirement on fundamental frequency for optomechanical system in ICF laser facility.

Laser-induced breakdown spectroscopy (LIBS) technique based on the analysis of typical for different materials integral relations calculated from broadband spectra of plasma is developed. The broadband spectrum (250-800 nm) is captured in real-time with fast spectrometer during the laser ablation process. By this way real-time automatic identification of the nature of constituent materials is performed.

We resume a complex study of a new Coproporphyrin III preparation obtained in vitro via microbiological synthesis in environment of a cultural medium of Arthrobacter globiformis with gaining of the coproporphyrin III tetrapotash salt sterilized aqueous solution with 94.5% purity. The main impurities have porphyrinic nature. The absorption spectrum shows that the preparation has multiple excitation bands in visible region with most pronounced maxima at 501 nm, 535 nm, and 556 nm, and a weak one at 606 nm. The most effective spectral range of its electronic states excitation can serve the region of a Soret band with maximum at 404 nm. Comparative luminescent and photosensitizing properties of Coproporphyrin III and Fotoditazin preparations have been studied. Luminescence and singlet oxygen quantum yields have been determined to be 0.03 and 0.37 (Coproporphyrin III) and 0.05 and 0.6 (Fotoditazin) correspondingly. A reduction of the quantum yields values at an introduction of a biological additive into aqueous solutions of the given preparations has been found. Preclinical trials of the preparation are performed. It is shown that Coproporphyrin III toxicity value is LD50 = 2400 ± 120 mg/kg, that allows to rank this preparation to the (V) class of almost nontoxical medicinal agents. It is shown that the preparation Coproporphyrin III has no teratogenic and allergenic properties and does not damage erythrocytes and thrombocytes. Absence of an influence of the preparation on the blood flow speed has been established. The results obtained thereby testify the absence of contra-indications for clinical tests of the Coproporphyrin III preparation on indicators of sharp toxicity.