The use of metal atom active media allows to convert optical signals with the transferring of the adjusted contrast. Due to the opportunities of metal vapor active media it makes possible to increase the intensity of the signal in the narrow spectral range. As a result, the signal-to-noise ratio can be dramatically increased. It makes possible to build active optical systems for high speed imaging of processes which are hidden by high intensive radiation. In the systems is available the image active filtration due to induced transition on metal atoms. Active optical systems with metal vapor brightness amplifiers (which is called Laser monitor), have shown the high efficiency for reducing the background radiation effect on the observing processes in the real-time mode. Moreover, the use of different active media makes it possible to change the spectral contest of the input signal with the increasing of the intensity. In the work the result of the research such systems are presented. The method of transformation IR images to VIS images is discussed. The work presents the results of the using of different active optical systems for high speed imaging.
The results of examination of characteristics of a CuBr laser with small active volume operated in the doublepumping-pulse mode with a lasing pulse repetition rate of 50 Hz are presented. Owing to the use of pumping sources with pulsed step charge of the working capacity, effective energy input to the active medium of the laser is realized. The potential to enhance the laser efficiency by choosing the optimum voltages of dissociation and excitation pulses and time delay values is discussed. It is confirmed that a more than twofold increase in the laser efficiency may be achieved through optimization and matched injection of the excitation-pulse energy into the active medium plasma. The maximum efficiency of the laser was 2.7%.
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.
The results of a comparative study of CuBr-laser energy characteristics with a small active volume operating in pulse-periodic mode and dual pump pulses are presented. The advantages of these regimes in the range 5-100 Hz and 5- 100 kHz for output power, the energy generation and efficiency of the laser are shown.
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.
The influence of minor H2 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.
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.
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.
Experimental study of PbBr laser was performed to study its performances and lifetime. Optimal pulse repetition rate was defined. Numerical model of PbBr laser was created to define the optimal Lead vapor pressure to achieve maximum output power and efficiency.
In the paper, we present new results of CuBr-laser study in a regular pulse mode with a high PRF and in a mode of modified double pumping pulses with PRF = 30 kHz. It has been shown a stable PRF over 500 kHz can be obtained.