Bragg enhancement in optically encoded volume plasma gratings in In-doped CdZnTe

Volume diffraction gratings, resulting from the plasma effect, are encoded in a new class of materials. The effect, based on persistent photoconductivity (PPC) associated with DX centers. Exposure of samples to light of sufficient photon energy generates free electrons via ionization of DX centers. Illumination with spatially varying light imprints a spatially varying free carrier density, which generates local refractive index changes via the plasma effect index changes. The extension of this effect to II-VI semiconductors offers the possibility of stability at higher temperatures, availability of high quality bulk crystals, and a wider range of excitation and readout wavelengths. Samples used in initial experiments were In-doped CdZnTe, grown using the Bridgeman technique