PROPAGATION OF A QUASI-TRANSVERSE WAVE BEAM IN PARATELLURITE CRYSTAL

The manner is discussed in which the wave vector surface anisotropy of paratellurite reflects on the diffraction divergence of quasi-transve rse wave beams near the preferred [110] direction. Analytical expressi ons are derived for the principal curvature tensor values that charact erize the diffraction beam spread in the (001) and (1(1) over bar0$) c oordinate planes. An experimental study is undertaken into the changes that the beam suffers in direction and shape as it is scanned near th e [110] direction.