Relaxation processes using transient grating technique

Transient gratings are produced by placing a sample in the interference reg ion of two intersecting intense laser beams. The optical constants of the s ample change due to the spatially modulated interference field. Several int eresting phenomena that occur in the excited state of organic molecules and in semiconductors can be studied by using the transient grating technique. Theoretical simulations are used as an additional tool to verify some of t he experimental results that give signatures of the technique for standardi zation of the obtained results. A brief description of these phenomena alon g with an example is given here.