optoacoustic effect

optoacoustic effect

[¦äp·tō·ə¦küs·tik i‚fekt] (physics) A phenomenon in which a periodically interrupted beam of light generates sound in a gas through which it is passing; this results from energy in the light beam being transformed first into internal motions of the gas molecules, then into random translational motions of these molecules, or heat, and finally into periodic pressure fluctuations or sound. Also known as thermoacoustic effect.