The behavior of the critical angles between a high-index isotropic medium and a biaxial crystal with arbitrary orientation of the optical tensor has been theoretically analyzed and numerically modeled. The results indicate that, as the biaxial crystal is rotated around an axis perpendicular to the interface, two critical angles appear, corresponding to the excitation of two eigen modes, which periodically vary with a period of π. An optical procedure for fully characterizing the optical tensor of a biaxial crystal is suggested on the basis of the twist-angle dependence of these critical angles. This procedure simply requires the measurement of the <i>p</i>- to <i>s</i>-conversion reflectivity against the sample rotation angle, with just one polished surface of a biaxial crystal.
© 2002 Optical Society of America
Fuzi Yang, Hongjin Gao, and J. Roy Sambles, "Relations between the Critical Angles and the Optical Tensor of a Biaxial Material," Appl. Opt. 41, 7264-7274 (2002)