Holographic correction of crystals for electrooptic modulators and deflectors

A method is proposed for compensating for the grown-in nonuniform birefringence common in plates or prisms of cubic electrooptic crystals, e.g., K(Ta, Nb)O
3
or CuCl. The method involves holography with two reference beams of orthogonal polarizations. In the reconstruction stage similar beams are used to generate a "real image" beam which is passed back through the crystal. In this way a uniformly polarized wavefront can be derived from the strained crystal. Phase modulation by the electrooptic effect can be achieved without destroying wavefront perfection, if the field is applied in such a direction that it would, in a perfect crystal, produce an optic axis coinciding with the light propagation direction used. Applications to electrooptic modulators and beam deflectors are considered.