Gennadiy S. Evtushenko

CuBr-Ne-HBr laser with a high repetition frequency of the lasing pulses at a reduced energy deposition in the discharge

Experimental and computer studies of the CuBr laser with periodic-pulse pumping are performed with and without addition of HBr. The analysis based on the numerical simulation reveals how additions improve the lasing characteristics of this laser at both typical (10 to 20 kHz) and higher (up to 100 kHz) excitation pulse repetition frequencies during the operation with a low energy deposition in the discharge. This allows the lasing pulse repetition frequency to be increased in the experiment to 750 kHz, which does not seem to be a limit as yet.

Influence of the discharge circuit inductance on output characteristics of a CuBr laser

The dependence of energy characteristics of an average-volume CuBr laser with and without addition of HBr on the rate of discharge current rise is studied. The energy characteristic is varied by connecting an additional inductance in the discharge circuit. It is shown that the average lasing power of the CuBr laser decreases tenfold with an increase in the inductance up to 4 μH. Under similar conditions, the average lasing power of the CuBr laser with addition of HBr decreases by less than two times. The fraction of lasing at the yellow line changes less. Thus, the presence of an electronegative addition to the active medium of a CuBr laser decreases requirements for the pulse power supply.

MnBr vapor active medium with a built-in reactor at 100-kHz pulse repetition frequency

Frequency and energy characteristics of a MnBr vapor laser with a built-in reactor, i.e., with gas vapors being produced within a gas discharge tube, and the dependence of the average output power on different parameters are studied in this work. The values of the GDT wall temperature and buffer gas pressure required for obtaining the maximum output power are determined. It is shown that active media of this kind are as good as media with a conventional method of gas vapor production. A pulse repetition frequency of 100 kHz is attained for the first time for a medium on Mn atom transitions. The use of this active medium as a brightness amplifier in active optical systems is described; the amplifying characteristics are analyzed.

Corona discharge in atmospheric pressure air when using modulated voltage pulses

Formation and decay of diffuse channels of a corona discharge in atmospheric pressure air when applying modulated voltage pulses to the electrode are studied. Photomultiplier tubes, a high-speed camera, and a CuBr vapor laser monitor are used to record the radiation from the corona discharge. It is shown that the radiation of diffuse corona discharge channels is time modulated, and the pulse repetition frequency is twice as high as the voltage pulse modulation frequency (∼ 290 kHz). It is also shown that the breakdowns can occur over a short distance when bending the corona discharge channel, which reduces the channel blurring.

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.

PRR performance of Cu- and CuBr-vapor lasers

Results obtained from comparative analysis of the pulse repetition rate performance of Cu- and CuBr-vapor lasers operated at high pump pulse repetitions (approximately 100 kHz) are reported. For a CuBr laser with a 8 mm diameter discharge tube the laser pulse repetition rate as high as 270 kHz was realized.

Laser Monitors for High Speed Imaging of Plasma, Beam and Discharge Processes

The imaging results of different processes blocked from the observation by the intense background light are presented in this paper. Active optical systems based on high-frequency brightness amplifier are used to decrease the negative factor of the glare. The experimental and modeling results on obtaining high pulse repetition frequencies (PRF) (more than 100 kHz) of copper bromide vapor brightness amplifiers operating in a low input energy mode are shown. The use of metal vapor brightness amplifiers for visual non-destructive testing of fast processes obscured by the glare is also discussed. It has been shown that the imaging method proposed in this paper proves to be the most reliable to obtain the information about objects or processes in a real time mode using high PRF CuBr active media.

Laser monitor for remote object visualization

The possibility of the visualization of remote objects using active optical systems with a copper vapor brightness amplifier has been investigated. Theoretical and experimental dependences for the field of view of the active optical system on the distance between the object and the brightness amplifier (laser monitor, laser projection microscope) have been studied. The visualization results suggest that as the object is moved farther from the brightness amplifier the field of view decreases and the quality of the obtained images gets worse. The maximum distance between the object and the brightness amplifier which is determined based on the superradiance pulse duration does not coincide with the visualization results. The field of view decreases as the distance between the object and the brightness amplifier increases. The feasibility of using a bistatic system for distant objects visualization has been shown.

Frequency-energy and amplification characteristics of the CuCl laser with an internal reactor

A new method for the creation of vapor of a working substance in lasers on atomic transitions is presented. The frequency-energy and amplification characteristics of the CuCl laser that is excited by a barrier discharge are studied. Such a method for the excitation allows an increase in the working lifetime of the active element, since the internal electrodes are rapidly destroyed in chlorine atmosphere. The experimental dependences show that such an approach makes it possible to construct lasers with output parameters that are no worse than the parameters of conventional lasers on metal halides and the amplification characteristics are similar to those of the known active elements.

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.