Optical absorption in glass: investigation using an acoustic technique

Experimental studies have indicated that chopped light entering a high pressure gas cell may produce sound in the gas even though the gas is not ir absorbing. Investigation into the source of this sound showed it to be due to interaction of the incident light with the cell window. The dependence of the sound pressure amplitude on cell pressure p0 indicates a p0(1/2) dependence, implying that the responsible mechanism is a diffusion process. Application of theory is successful in explaining both the quantitative and qualitative aspects of the data if the existence of an optically absorbing surface layer is assumed. The results obtained here are in general consistent with data obtained from studies of laser damage in glasses at high intensities.