Dmitriy V. Shiyanov

CuBr Laser Excited by a Capacitively Coupled Longitudinal Discharge

The paper presents the study of the CuBr laser energy characteristics using capacitively coupled discharge excitation. We have studied the effect of the addition of HBr on laser performance for gas discharge tubes of different bore diameter at various input power conditions. When adding HBr pulse and average output power as well as laser efficiency more than double increase due to the shortening of the current pulse rising time and its duration. The total maximum average lasing power of 3.7 W was obtained at 0.27% efficiency. In the paper, we also notice that when adding admixtures capacitively coupled discharge pumping is superior to traditional glow discharge pumping.

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.

Influence of H 2 and HBr additives on Cu and CuB vapor lasers performance

Investigations of the output parameters of CuBr (Cu)+HBr laser systems have shown that HBr additives to the CuBr laser active medium result in an increase ofthe laser output power and efficiency that compares, in this case, with that of a CuBr laser with H2 additives. It has been found that the vapor of working substance are additionally produced in gas-discharge tubes (GDTs) less than 2 cm in diameter due to expulsion of copper atoms from the GDT walls by HBr. The results of simulating the kinetics of the copper vapor laser active medium with HBr additives show that the enhancement of the laser performance parameters can be explained by the processes of chemical transformation of copper from the solid phase into the gas one.

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.

High pulse-repetition rate metal and metal halide vapor lasers

In the paper, we show the present state of the art of high pulse repetition frequency (PRF) metal vapor lasers (MVL’s) and metal halide vapor lasers (MHVL’s) development. We also analyze underlying physical features, which limit optimum and maximum PRF of the above lasers and mention the results of the experimental study of high PRF CuBr and PbBr2 vapor lasers. By use of a powerful tasitron as a switch and a small hydrogen additive to the buffer gas Ne we obtained the output power of a practical use with PRF more than 200 kHz. Given PRF 250 kHz and a laser tube of diameter 2.5 cm and length 76 cm, we have got the output power 1.5 W. For PRF 200 kHz and 100 kHz, the output power 3 W and 10.5 W has been got respectively without gas flow across the discharge tube. Experimental and numerical modeling data evidence that the small H2 (or Cs) additives improve the frequency and output features of MVL’s and MHVL’s.

Metal halides vapor lasers with inner reactor and small active volume.

Investigation of the energy characteristics of copper, manganese, lead halide vapor lasers with inner reactor and small active volume 90 cm3 was made. The optimal operating pulse repetition rates, temperatures, and buffer gas pressure for gas discharge tubes with internal and external electrodes are determined. Under identical pump conditions, such systems are not inferior in their characteristics to standard metal halide vapor lasers. It is shown that the use of a zeolite halogen generator provides lifetime laser operation.

Influence of gas mixture content and pumping conditions on CuBr+Ne+H2 (HBr) vapor lasers performance

Dependence of a CuBr laser output on the pressure of H2- and HBr- additives into active medium has been investigated. Optimal H2 and HBr densities for maximal laser output have been determined when pressure of Ne buffer gas was varied in the range from 10 up to 100 torr. Laser output has been studied with variation of the active compound (CuBr) pressure in the range from 0.1 up to 0.6 torr for gas discharge tubes of different volumes. The optimal additive pressure has been shown to linearly depend on a voltage across gas discharge tube at high pressure of the buffer gas. The optimal density of copper bromide decreases while pulse repetition rate increases up to 100 kHz. It is assumed that accumulating of Cu-atoms takes place in the active medium due to decreasing of interpulse period.

Metal and metal halide vapor lasers: new opportunities

The influence of minor H 2 and HBr additives on the generation characteristics of some copper bromide vapor lasers is experimentally investigated. It is demonstrated that at optimal concentrations of both admixtures, the average generation power increases by five times for lasers with small active element diameters, and by two times for lasers with major diameters. For the maintenance of an adjusted concentration of the admixture, the original construction of the HBr generator is developed, which in the reversible regime removes not only the HBr surplus from active volume of the laser, but also at least some of harmful products of the working laser. The obtained results are applied to the development of a sealed-off self-heating copper bromide vapor laser with an integral HBr generator, operating in the automatic regime.