Pulsed laser irradiation effect on GaAs in transparent liquid media

Q-switched ruby laser action (pulse duration 80 ns) on the surface of GaAs single crystal in the media of ethyl (C2H5OH) and isoamyl (C5H12O) alcohol's and toluene (C7H8) have been studied by in situ methods. Thermal radiation of heated zone in a spectral range of 0.48-0.55 μm and reflected probe radiation (λ=1.06 μm) were detected. The brightness temperature of the laser heated layer surface and dynamics of optical reflectivity were studied at irradiation energy density W=0.1-1 J/cm2 (below threshold of GaAs surface destruction). It has been established that the thresholds in alcohol's and toluene are practically equal and do not differ of the threshold in air. This effects can be explained by very low temperature conductivity of alcohol's and toluene in comparison with GaAs and more effective than in air radiation absorption in surface layer of samples. The dependence of brightness peak temperature of heated zone and melt duration of GaAs on the laser energy density were determined. The melt duration values for irradiation in liquid are higher than the results for irradiation in air