<title>Atmospheric optoacoustics of power parameters of a high-power laser beam</title>

Abstract

The propagation of high-power laser radiation (HPLR) in an atmosphere is accompanied by radiation of acoustic waves.The characteristics of optoacoustical signals depend on factor of absorption HPLR and its power parameters. It is necessary to take into account absorption and attenuation of acoustic waves arising in the channel HPLR, in tasks of restoration of power parameters HPLR on optoacoustical signals. The deforming influence of an atmosphere on amplitude-frequency a spectrum registered on distance up to 1 km of optoacoustical signals is reduced to the account of classical absorption, of turbulent and preearthly attenuation. In work the questions of optimum program processing registered in experimental measurements of optoacoustical signals generated by the channel HPLR in an atmosphere are considered. The developed algorithm is realized in the created software <<Atmospheric optoacoustics>, allowing in real time on the basis of the meteorological data to compensate deforming influence of an atmosphere and spreading surface on amplitude-frequency the characteristics of optoacoustical signals of a sound range of frequencies

Sound generation in the atmosphere upon exposure to high-power milli- and microsecond laser pulses

“…3b it can be seen that the signal shape is well described by blast N-wave (5). This is also confirmed by laboratory experiments [24] with a pulsed Nd:YAG laser (λ = 1.064 μm) whose radiation was focused at a distance of 10 cm into air, a breakdown was initiated, and an acoustic pulse was registered from the breakdown region.…”

“…9a, the frequency of the maximum is max 4 5 f = − kHz. Formula (1.20) presented in [17] and cited with reference to [13] was absent there, and conclusion about methodical errors of experiments performed in [2,3] following from it (see [17], pp. 62-63) is incorrect.…”

“…Further progress here is connected with practical application of the optoacoustic effect to diagnostics of thermooptical and breakdown regimes of laser radiation propagation, investigation of the atmospheric (temperature, humidity, and wind velocity averaged over the atmospheric layer) and HPLR parameters (effective beam radius, energy, angular beam divergence, and laser radiation absorption coefficient) [11][12][13][14][15][16][17].…”

“…A brief review of experimental and theoretical works on laser-induced shock waves through 1990 was presented in [16]. Applied aspects of atmospheric optoacoustics of laser beams were considered in [17].…”