Generation of Coherent Phonons via Thermomodulation Induced by Interfering Laser Beams
A new method of phonon generation is presented. Thermomodulation of a thin metallic transducer deposited onto a single crystal of PbMoO4 is induced by two interfering cw single-frequency dye lasers. A monochromatic phonon beam is generated with a frequency equal to the beat frequency of the two lasers. The high directionality of the phonons proves their coherency.