Enhancement of the photorefractive gain at 13–15 μm in CdTe using alternating electric fields

Abstract

We report large enhancement of the two-beam-coupling gain in vanadium-doped cadmium telluride. We used the applied-alternating-field method with square and sinusoidal waveforms. With nominally square waveforms gain coefficients in excess of 10 cm−1 have been measured, which significantly exceed the absorption coefficient of 2 cm−1 for our sample. The results agree well with theory when the major effects of the ac waveform shape, internal field screening, and large-signal effects are taken into account.