Four Wave Mixing In Doped And Un-doped KNSBN Crystals

Recently it has been found the photorefractive materials are some of the most sensitive materials for performing four-wave mixing and all kinds of the digital optical computing by using only a few milliwatt continuous laser beam. The photorefractive crystal KNSBN [(K
_0.5
Na
_0.5
)0.4 (Sr
_0.61
Ba
_0.39
)
_0.8
Nb
₆
O
₂
], comparing with BaTiO
₅
, has the same or higher optical sensitivity and can be much more easily grown to produce doped and un-doped crystals of adequate size and optical quality for numerous applications. In this paper, we report the experimental results on the temporal responses and the reflectivity of the optical phase conjugation in the photorefractive crystal KNSBN.