IMAGE HOLOGRAPHY IN CDF2-GA CRYSTALS

The recording of an image hologram in CdF2:Ga crystals at room tempera ture is reported. Writing the phase holographic pattern utilizes a uni que property of Ga and In doped CdF2 crystals, namely, the bistability of these dopants. In contrast to CdF2:In crystals, in which there is only one bistable center, the holographic experiment reveals two diffe rent bistable centers in CdF2:Ga. Room temperature bistability is rela ted to Ga, while the low temperature center resembles very much the pr operties of In, likely a non-intentional In dopant of the CdF2:Ga crys tals. The holographic sensitivity of doped CdF2 crystals compares favo rably with sensitivity of standard photorefractive materials. The main advantage for some applications of using the novel mechanism is the i nherently local nature of the light-induced refractive index changes. (C) 1998 Elsevier Science B.V. All rights reserved.