Optimal conditions for thermal fixing of volume holograms in Fe : LiNbO3 crystals

We analyze and compare two typical recording and thermal fixing procedures of a volume hologram in a Fe:LiNbO3 crystal (low-high-low procedure and hig h-low procedure). We consider the kinetics of the recording, compensating, and developing processes by taking into account the ratio of the conductivi ties between the protons and the electrons as a function of temperature. Fr om the analysis the optimal environmental conditions tin terms of the fixin g temperature and the compensation time) for each fixing procedure can be d educed for a crystal with given material parameters. (C) 1999 Optical Socie ty of America.