Femtosecond time-resolved study of dynamic laser-induced nonequilibrium grating in Si films

摘要

Kinetics of the decay of a dynamical grating formed by nonequilibrium charge carries in thin monocrystalline silicon films under femtosecond laser excitation are studied. A case of limiting concentration of charge carriers is analyzed. Contributions of ambipolar diffusion and Auger- recombination in the decay of a dynamical grating are estimated. At high intensities an effect of the long-lived dynamical grating is discovered.