Picosecond time-resolved impulsive stimulated brillouin scattering in rochelle salt

Longitudinal acoustic phonons were excited by crossing two picosecond pulse laser beams in Rochelle salt. The time dependence of phonon oscillation was detected by the time delayed third probing beam. From the recorded signals for three crossing angles, the phonon frequencies were deduced to be 1.57GHz, 1.12GHz and 506MHz. The results indicate that the thermal absorption process (ISTS) is predominant for the present impulsive stimulated scattering.