Autocorrelation by transient gratings on photo-darkened semiconductor-doped glass

Abstract Autocorrelation measurement by transient gratings on the α-Si:H, GaP, CdS, and semiconductor-doped glass OG550 samples were performed. Because of the α-Si:H, GaP and CdS long carrier lifetime, a coherence width of 15 ps was measured for the mode-locked optical pulses (70 ps duration) at 532 nm. The laser-induced photo-darkening effect on the OG550 shortened its carrier lifetime and a 67 ps autocorrelation time was measured that scales with the optical pulse duration.