Photorefractive gratings formed in a Fe : CdTe crystal by nanosecond laser pulses

An investigation was made of photorefractive gratings formed by nanosecond laser pulses in an Fe-doped CdTe crystal. Pulsed pumping (λ = 1.06 μm, τ_p = 10 ns) with the maximum gain coefficient Γ = 0.3 cm^–1 induced a fast photorefractive effect in this crystal, characterised by a high electron mobility (μ_e = 1500 cm² V^–1 s^–1). The orientational dependences of the gain coefficient, and its dependences on the grating period and on the intensity of the recording radiation, were used to calculate the Debye screening length, the effective concentration of the carrier traps, and other parameters of the investigated crystal, including the ambipolar conduction coefficient taking account of the competition from the minority carriers.