A Study on the Selective Erasure of Photorefractive Holograms in Fe∶LiNbO_3 Crystal

The principle and method of selective erasure are proposed and discussed. Relevant theories of selective erasure are given according to the characters of fixed and unfixed photorefractive holograms. Some methods of introducing π phase shift light intensity patterns (with regard to that used for recording) are reported. By recording the complementary hologram leading to changes in complementary refractive indices, the process of selective erasure can be realized. At the same time, some experimental results are also demonstrated and analyses of the results are given.