G. S. Evtushenko

A bistatic laser monitor

A prototype of a bistatic laser projection system employing copper bromide vapor based active media is presented that allows remote objects and high-speed processes to be monitored online. The proposed scheme employs two active elements: one in the source for lighting the object and another in the image brightness amplifier.

Dynamics of apokamp-type atmospheric pressure plasma jets initiated in air by a repetitive pulsed discharge

This paper presents the research data on the dynamics of a repetitive pulsed discharge as a source of plasma jets in atmospheric pressure air and on the conditions under which the discharge produces apokamp–plasma jets ejected from the bending point of the discharge channel with no gas supply through the discharge region. The data suggest that the formation of apokamps requires the application of a large number of voltage pulses to sharp-ended electrodes at a repetition frequency of several to tens of kilohertz. Before an apokamp starts developing, the apokamp-initiating discharge passes through a spark stage and then becomes diffuse. Next, at the site of electric field amplification, the discharge channel gives rise to a bright branch from which plasma bullets escape with a velocity of ∼200 km/s. The images of different discharge and apokamp stages are presented.

High Prf Metal Vapor Laser Active Media For Visual And Optical Monitoring

In this paper the feasibility of using metal vapor lasers for visual and optical monitoring of fast processes is discussed. The theoretical calculations consistent with the experimental study have been performed. The possibility of visualizing objects with pulse repetition frequency of the brightness amplifier up to 60 kHz has been demonstrated. The visualization results of the corona discharge are also given.

CuBr Laser for Nanopowder Production Visualization

The paper presents first results on the use of a CuBr laser for high-speed imaging of the process of nanomaterial synthesis. Various imaging circuits are considered. A possibility of full suppression of stray background light, which is the laser monitor main advantage for diagnostics, is shown. The application areas for each circuit are discussed.

Amplified Spontaneous Emission on Sodium D-lines Using Nonresonant Optical Pumping

We describe experiments on the excitation of amplified spontaneous emission on the D-lines of sodium (D2 = 588.9 nm; D1 = 589.6 nm) with longitudinal optical pumping with a large detuning from the D2 line toward shorter wavelengths. The radiation spectra are measured, showing gain on both lines, at a Na concentration of (1–5) × 1014 cm–3, buffer gas (helium) pressure of 600 Torr at the working temperature, and pumping power density of more than 1.5 MW/cm2. The time characteristics show that the output radiation varies versus the concentration of sodium atoms in the active medium. The dependences of radiation absorption at the D-lines of sodium on the concentration of Na atoms and buffer gas pressure are given.

Study of a High-Frequency Copper Bromide Vapor Active Medium in the Superradiance Mode

Results of the experimental study of two high-frequency active elements of different sizes of a CuBr laser operating in the generator, single-pass amplification, and superradiance modes are presented. A pulse repetition rate of 195 kHz is attained for the first time in the supperradiance mode. Using the method of express estimation of the radial profile, it is shown that the gain profile does not change significantly throughout a wide pulse repetition rate range (up to 195 kHz) in the case of a small-diameter active element.

An image-brightness amplifier based on copper bromide vapor for operation at increased superradiance pulse duration

We present data on the development and application of an image-brightness amplifier based on copper bromide vapor intended for the visualization of objects occurring at distances above 5 m from the detecting equipment. An increase in the superradiance (gain) pulse duration was achieved by decreasing the repetition frequency of pumping pulses (to 3 kHz) and increasing the capacitance of the capacitor bank (up to 3.4 nF) so as to increase the deposited pulse energy. The basic possibility of creating active optical systems with brightness amplifiers (laser monitors) for the visualization of objects and processes occurring at large distances from a registration system is demonstrated.

Control system for bistatic laser monitor

The article presents the design of control systems for the bistatic laser monitor based on CuBr-lasers.