Abstract:
Generation of hypersonic waves in organic dye solutions was observed experimentally for the first time when excitation was provided by two almost opposite interfering ultrashort light pulses. It was found that a degenerate four-wave interaction in absorbing layers excited simultaneously two mutual orthogonal acoustic gratings that contributed to a reversed wave. A study was made of the dependences of the intensity and of the quality of wavefront reversal in the case when delayed ultrashort pulses were diffracted by both gratings.