Laser generation of acoustic waves at a periodic domain structure in lithium niobate

Generation of coherent acoustic oscillations due to the interaction of lase r pulses with the periodic domain structure formed in a lithium niobate sin gle crystal is observed. It is found that the excitation of acoustic waves is most efficient when the generated wavelength is equal to the period of t he domain structure. The proposed mechanism of the optical generation of ac oustic oscillations consists of the photogeneration of free carriers, which compensate the polarization fields within the domains, and the occurrence of alternating elastic stresses caused by the piezoelectric effect. (C) 200 0 MAIK "Nauka/Interperiodica".