Abstract

In transient induced grating experiments the decay of an intensity or phase grating produced by interference of two coherent light pulses in e.g. solids or liquids is monitored by diffraction of a third probe pulse. Generally, the intensity of the first order diffracted beam is monitored as a function of time delay between the excitation pulses and the probe pulse to provide information on the dynamics of diffusion and recombination of the photoexcited species /1/. If the two interfering excitation pulses are additionally delayed with respect to each other phase relaxation processes can also be studied /2/. We report a further extension of this technique, which allows the study of the temporal variation of the spatial shape of an originally sinusoidal index grating by simultaneous detection of the decay of different diffraction orders.

© 1986 Optical Society of America