Diffraction efficiency of localized holograms in doubly doped LiNbo(3) crystals

The diffraction efficiency of M holograms superimposed in the volume of the recording medium is proportional to 1/M-2, me present a method, based on nondestructive localized holograms in a doubly doped LiNbO3 crystal, that allows us to also record M holograms in the same volume without an exposure schedule or a diffraction efficiency that has 1/M dependence. We compare experimentally the final diffraction efficiency obtained with the localized and distributed recording methods. (C) 2000 Optical Society of America OCIS codes: 090.0090, 210.0210.