A. S. Boreysho

Detection of explosives traces on documents by attenuated total reflection method

The technical devices of explosives trace detection are discussed in this work. The attenuated total reflection method (ATR) is considered for detection of explosives traces on different things (documents, clothes, fingers). The results of experiments with Fourier spectrometer and ATR attachment for explosive trace detection are presented. The optical scheme and design of the compact testing device are discussed. The device includes the document information scanner and at the same time - the trace detector of explosives on the document cover.

Problems and solutions in COIL gas dynamics

Main gas-dynamic phenomena of COIL are considered as well as theoretical and experimental results. Four parts of COIL are analyzed: SOG, nozzle, resonator cavity and diffuser. Numerical simulation presented of the outer aerodynamics flowfield around the output window at the airplane.

Remote detection and recognition of bio-aerosols by laser-induced fluorescense lidar: practical implementation and field tests

Recognition of aerosol clouds material at some significant distance is now a key requirement for the wide range of applications. The elastic backscatter lidar have demonstrated high capabilities in aerosol remote detection, cloud real-time mapping at very long distances for low-concentration natural aerosols as well as artificial ones [1]. However, recognition ability is required to make them more relevant. Laser-induced fluorescence (LIF) looks very promising with respect to the recognition problem. New approach based on mobile lidar complex [2] equipped by spectrally-and range-resolved LIF-sensor is described as well as some results of field tests. The LIF-sensor consists of four-harmonics Nd:YAG laser equipped by an output expander to provide final beam divergence <1 mrad, 500-mm aspheric Cassegrain-type multi-wavelength receiving telescope, set of single-element receivers for measurement of the elastic backscatter radiation, and multi-element receiver with monochromator for spectrally-resolved LIF measurements. The system is equipped by 2-axis scanning mirror and variable-FOV video-camera collimated with the lidar scanning direction. The LIF-lidar is mounted on a truck-based platform (20-feet container) as a part of multi-purpose mobile lidar complex and adjusted for field conditions.

All-solid-state laser system with coherent combining of independent channels via common laser beam

The multichannel laser system with coherent combining as a result of fourwave mixing in active laser media is proposed.

System for transmitting energy and information using laser radiation for control of the shape of large space-based antennas

The article is devoted to wireless and fiber-optic transmission of laser energy for operation of special actuators and control of the shape of the deformable space-based antenna.

Principles of influence on the spectral properties of solid-state laser with loop cavity

Principles of spectral narrowing of radiation of laser with loop cavity due to phase conjugation phenomenon are discussed. The gain gratings in active media results in competition in longitudinal modes and spectral selectivity.

High-energy compact-size diode-pumped Nd:YAG laser with self-pumped phase-conjugate dynamic cavity

Compact-size, multiloop, self-phase-conjugated Nd:YAG laser pumped by 4D diode stacks was studied. The use of a passive LiF:F2-Q-switch resulted in pulse train oscillation depending on the passive Q-switch position and length of diffractive feedback in the cavity. The laser energy of up to 2.55 J in trains of 13 pulses with 11-ns duration was obtained.

Compact transversely diode-pumped Nd:YAG laser with a self-pumped phase-conjugate multiloop cavity

A compact high-power repetitively pulsed Nd :YAG laser with transverse diode pumping and a multiloop self-pumped phase-conjugate cavity is presented. The obtained pulse trains have an energy of with beam quality , a divergence of , and a spatial brightness of . The peak power of single-frequency pulses exceeds at a pulse energy of . The laser bandwidth is .

Optical beam quality of COIL

The questions of optical beam quality of COIL are considered. The classification and meanings of different type of optical aberrations in COIL is presented. The ways of compensation of amplitude aberration by structure-parametrical optimization of the unstable resonator are offered. The scheme of automatically resonator alignment for compensation of phase aberrations originated from misalignment is presented. The 3D numerical modeling and investigation of gas flow and chemical kinetic in COIL is fulfilled. The scales and magnitude phase aberrations coimected with gas flow non-homogeneities are analyzed. The optimization of the COIL nozzle bank length from point of view of maximal beam brightness is fulfilled.

Optical heterodyning in differential tunable CO 2 laser systems

Long-wave infrared (LWIR) differential laser systems based on single-frequency pulsed CO2 lasers are used in heterodyne lidars for detection of atmospheric pollutions at extremely far distances. Issues related to control of the two-channel tunable single-frequency CO2 laser system, which includes two pulsed TEA laser and four CW wave-guide CO2 lasers (two injectors and two local oscillators) are discussed. The special hardware and software -Automatic Frequency Control system (AFC) - have been developed for the effective operation in wide spectral range (>60 lines of CO2 laser). The main task of this system is to keep optimal ratio between a frequency of the injection laser generation and modes of the TEA lasers resonator. The optimal ratio provides maximal probability of the single-frequency pulse generation taking the TEA chirp into account. Experimental data presented on the temporal and spectral structure of the TEA laser pulse generated with injection of the single-frequency CW radiation.