The space charge electric field associated with a photorefractive grating generates deformations (through piezoelectricity) which in turn, modify both the electrooptic and dielectric constants. These modifications are of importance and must be taken into account. For instance, in barium titanates samples the dielectric constant epsilon sub 11, determined using spatially uniform applied electric fields, varies by a factor of two between clamped and unclamped crystals. Hereafter, we demonstrate that these ...
A large number of proposed or demonstrated architectures for optical computing takes advantage of the unique properties of photorefractive crystals. Efficient operation requires large optical nonlinearities. BaTiO3 exhibits these strong refractive index changes due to its large electro-optic coefficient. Unfortunately it has a low sensitivity and this a slow response time. BSO is much more sensitive but its electro-optic coefficient is smaller. It is consequently necessary to induce large internal ...
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