Photoacoustic characterization of cw argon-ion laser irradiation of Ge

Photoacoustic detection has been used to characterize cw argon-ion laser irradiation of Ge. Laser-induced heating, damage, and melting are studied. The heating process is seen to be nonlinear with incident laser power until close to melting. Two laser-induced-damage time constants are obtained associated with thermal etching and oxidation. An incident power level of 2.24 W is estimated to initiate the melting of an undamaged Ge surface under the experimental conditions described.