Several methods are investigated to avoid undesired erasure during read-out of volume phase holograms stored in photorefractive crystals. We present results on thermal fixing and on the utilization of two-step excitations. Furthermore we propose two new methods to read volume holograms nondestructively using light of low photon energy not sufficient to excite charge carriers.
Hans C. Kulich,
Romano A. Rupp,
"Hologram Stabilization In Photorefractive Crystals", Proc. SPIE 1017, Nonlinear Optical Materials, (8 March 1989); doi: 10.1117/12.949974; https://doi.org/10.1117/12.949974