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)O3or 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.