Nanosecond photorefractive gratings in CdTe:Fe crystals with high mobility

摘要

Abstract: Measurements are presented for the photorefractive grating recording under pulsed excitation in the crystal of CdTe doped by Fe. The crystal under study is characterized by high electron mobility in comparison with typical value.THe photorefractive parameters of the crystal such as gain factor, Debye screening length, effective density of charge traps as well as effective electro-optic constant have been measured on the basis of gain/grating spacing, gain/crystal rotation angle at different recording beam polarizations, and gain/intensity at different crystal orientations dependencies. The electron-hole competition influence on the crystal photorefractive performance is discussed. The fast photorefractive effect was shown to occur under pulsed excitation maximum gain factor, $Gamma@, being equal to approximately 0.3 cm$+$MIN@1$/ without any external electric field. Different self-action effects accompany two-beam coupling are discussed. These are two photon absorption, free carrier generation, self-action of laser beams. The photorefractive effect was separated in its pure form from the various nonlinear optical phenomena. !11