Ultrafast processes in silicon studied by transient gratings

Light induced grating measurements on monocrystalline silicon have been performed with excitation by 25 ps pulses both at 532 and 1064 nm. 1300 nm radiation was used as probe pulse. Self-diffraction experiments with parallel and orthogonal polarization of the beams allow us to determine coherence time and duration of the pulses, respectively. By measuring the grating decay time at various grating periods both the ambipolar diffusion constant and linear and surface recombination times can be obtained. Furthermore, it was demonstrated that parameter measurements in silicon can be performed using the diffraction "in reflection."