PHOTOREFRACTIVE GRATINGS FORMED IN AN FE-CDTE CRYSTAL BY NANOSECOND LASER-PULSES

An investigation was made of photorefractive gratings formed by nanose cond laser pulses in an Fe-doped CdTe crystal. Pulsed pumping (lambda = 1.06 mu M, tau(p) = 10 ns) with the maximum gain coefficient Gamma = 0.3 cm induced a fast photorefractive effect in this crystal, charact erised by a high electron mobility (mu(e) = 1500 cm(2) V-1 s(-1)). The orientational dependences of the gain coefficient? and its dependence s on the grating period and on the intensity of the recording radiatio n, were used to calculate the Debye screening length, the effective co ncentration of the carrier traps, and other parameters of the investig ated crystal, including the ambipolar conduction coefficient taking ac count of the competition from the minority carriers.