Effective Room-Temperature Broad-Band Recording of 3D Dynamic Holograms in CdF_2:Ga Crystals

摘要

Photochromic CdF_2:Ga crystals with bistable impurity centers were effectively used for the dynamic recording of holograms and readout over the visible and near IR spectral regions at spatial frequencies of up to 5000 mm~(-1) at room temperature. The diffraction efficiency of the dynamic holograms was as high as 60% at maximum and exceeded 1% when the beams' intensities were in the ratio 1:100. As one goes from the low temperatures (≤200 K) to 300 K, the peak diffraction efficiency of the dynamic holograms decreases approximately by a factor of 1.5, while the speed of their response and photosensitivity in the long-wavelength spectral region increases by more than an order of magnitude. For the sake of comparison, the dynamic holograms were recorded under the same conditions as the widely used electrooptical SBN crystals. Comparative analysis ascertained a unique combination of the useful features offered by CdF_2:Ga crystals in holography.