T. Baade et al., A simple method for image restoration and image pre-processing using two-wave mixing in Bi12TiO20, J OPT A-P A, 3(4), 2001, pp. 250-254
Optical information processing is one possible application of photorefracti
ve crystals. In contrast to other methods where photorefractive crystals wi
th high electro-optic coefficients (e.g. BaTiO3) or an applied electric fie
ld for increasing the beam coupling efficiency were applied, we used a simp
le two-wave mixing (TWM) set-up with a Bi12TiO20 (BTO) crystal without appl
ied electric field to restore the intensity profile of a distorted image an
d for edge amplification and detection.