Coherent selective erasure of superimposed volume holograms in LiNbO3

Abstract
Selective erasure of superimposed holograms recorded in Fe−doped LiNbO3 is reported. This process consists of photoinducing complementary refractive index changes which cancel the previously recorded changes. It can be applied to any stacked hologram in the crystal volume as well as to any part of one selected hologram; in this last case it performs the Boolean operation exclusive or.