Fedor A. Gubarev

Long-pulse copper bromide laser

In this paper the results of investigation of copper bromide vapor laser with pulse duration up to 320ns are presented. For pulse extension, the system of limitation of discharge current, based on a composite switch consisting of a thyratron and a tacitron connected in series, was used. This method allows to limit the excitation of lasing transitions in the initial stage of the discharge, thereby increasing the inversion lifetime. Researchers have shown that the longest duration of lasing is achieved with relatively low pulse repetition frequencies (2-5 kHz) in tubes of a medium and large diameter.

Studying of solid-state power supply unit of CuBr-laser

The paper presents the results of the study of solid-state power supply units for pumping CuBr-lasers of various geometry. The possibility of developing solid-state high-frequency (>100 kHz) power supply units is demonstrated, and the results of simulation and breadboarding of solid-state high-voltage power supply units for pumping CuBr-lasers are discussed.

Capacitive-Discharge-Pumped CuBr Laser With 12 W Average Output Power

This paper presents the study of the energy characteristics of a medium scale CuBr laser (1130 cm3 active volume) pumped by a longitudinal capacitive discharge. The output power dependences on the equivalent operating capacitance and on the ratio of high-voltage and ground electrode capacitances are studied. The best characteristics are obtained when the high-voltage electrode capacitance exceeds the ground electrode capacitance or when the electrode capacitances are equal. The presence of a threshold value for pumping power, above which the introduction of HBr additive into the active volume improves laser performance, is also noted. The total maximum average lasing power was 12 W at ~ 0.5% efficiency when the capacitances of both the electrodes were 1190 pF.

Copper bromide laser monitor for combustion processes visualization

The results of observing in a real time the process of aluminum nitride synthesis occurring by combustion of aluminum nanopowder in the air are discussed in the paper. The obtained results convincingly evidence that observation of microstructure formation processes by means of the laser monitor is quite accessible. The video images allow seeing such structure formation phases as aluminum nanopowder oxidation, oxygen displacement by nitrogen, and cooling. The speed of combustion process and its peculiarities have been determined which is important for the process optimization for the purpose of obtaining ceramic powder with certain phase composition and crystal phase morphology.

About CuBr laser pulse duration in an unstable discharge

The paper presents results of studying the influence of excitation conditions of the copper bromide vapor laser on the lasing pulse duration. It is revealed that when the discharge transitions to an unstable mode increased pulse duration of lasing up to 200 ns and more is observed.

High-speed process visualization using CuBr-laser

The paper discusses the use of a CuBr-laser active medium for visualization of high speed-processes obscured by background light. The methods of laser illumination and laser monitor are suggested.

Monitoring of objects hidden from observation by stray lighting

The paper presents state of the art for laser projection microscopes and their application for monitoring objects and processes hidden from view of an observer by a layer of bright luminous plasma. We show the possibility of registration of an image, which is obtained using laser projection microscope and is formed by a single pulse of the optical amplifier. Laser monitor based on CuBr-laser with a frame-by-frame imaging has been used for the first time. The paper presents the results of visualization of the process of self-propagating high-temperature synthesis, which is attended by intense stray lighting in real-time mode using synchronizing system of an optical amplifier and a highspeed camera.

Perspectives of capacitive discharge application for pumping of metal vapor lasers with modified kinetics

The paper presents the study of CuBr lasers excited by longitudinal capacitive discharge. Performance characteristics of the laser with outer electrodes using various excitation circuits are considered. The effect of HBr additive on the discharge and lasing characteristics of capacitively excited CuBr laser is contrasted to that of conventional pulse-periodic discharge with inner electrodes. It is shown that when using such a type of pumping the influence of electronegative HBr additive depends on the type of the excitation circuit that is used. The best results are achieved when using the circuits providing a high rate of rise of the discharge current. The maximum increasing of output power and laser efficiency (up to 3 times) with HBr additive was obtained in a gas discharge tube of a relatively large bore (2.7 cm), which suggests good output power scaling of CuBr-HBr laser with capacitive discharge pumping.

Investigation of extracting information from vibrating objects by digital speckle correlation

The paper presents results of studying the quality of extracting information from vibrating objects. A capability of getting information from vibrating objects situated at an arbitrary angle to the observer is investigated. Reliable extracting information from the test object situated within an angle of +/- 50 degrees relative to the plane perpendicular to an observer is demonstrated. A possibility of using a single lens in order to vary the laser beam diameter for applying in the tasks of extracting information from vibrating objects is also considered.

Copper bromide laser for optical communication

The paper presents a variant of wireless data transmission implementation using a pulse gas-discharge copper bromide laser. The possibility of the time-pulse modulation of the copper bromide laser emission in accordance with the digital code received from a personal computer was presented. It is shown that the lasing frequency modulation in the range of 8 microseconds leads to the lasing pulse energy modulation within 20-25%. This fact has a substantial significance for the implementation of the optical atmospheric communication link based on the pulsed self-terminating lasers, including the implementation of the over-the-horizon link. The paper discusses the experimental results concerning the digital code influence on the laser energy and electrical characteristics.