Engineering Physics Annotation << Back A new method for photoacoustic monitoring of laser ablation Il'ichev N.N. Samokhin A.A. New possibilities for experimental investigation of nanosecond laser ablation of condensed matter are presented. The new method is based on the use of a laser pulse with a periodically modulated intensity and acoustic diagnostics arising in the irradiated target modulated pulse pressure. The behavior of the amplitude and phase of the high-frequency parts of the photoacoustic signal provides new information about processes in the irradiation zone during laser pulse action. At low intensities high-frequency modulation amplitude behaves like laser modulation amplitude while at higher intensities this behavior becomes strongly nonmonotonous. The effect which we found is probably due to mutual compensation of contributions from thermal and vaporization mechanisms of acoustic signal generation. Phase of modulated part of the photoacoustic signal is also changes in magnitude and sign as laser intensity grows. This variation can be used to monitor irradiated surface displacement during laser pulse action. Key words: intensity modulation, laser ablation, photoacoustic signal, evaporation. Contacts: E-mail: asam40@mail.ru Pp. 38-47.