Non-collinear acousto-electro-optic tunable filter configurations in LiNbO/sub 3/

A formulation which leads to the determination of wide angular aperture AEOTF (acousto-electro-optic tunable filter) configurations in LiNbO/sub 3/ crystals is developed. It is shown that for certain orientations of the bias electric field the LiNbO/sub 3/ crystal becomes optically biaxial. The Bragg angles of noncollinear tunable filter configurations in the artificially biaxial LiNbO/sub 3/ are determined explicitly and their dependences on the intensity of the bias electric field and the acoustic wave propagation direction are treated analytically. It is shown that for, bias electric field intensities widely used in LiNbO/sub 3/ devices, 10 kV/cm to 100 kV/cm, up to four noncollinear AEOTF configurations can be obtained for certain directions of acoustic wave propagation.