Abstract

The planar optical waveguiding method which is used extensively for the measurement of the refractive index of isotropic thin films has also been applied to the determination of the three principal refractive indices n₁, n₂, n₃ of anisotropic films.1 As shown in Fig. 1, a prism is used to couple a laser beam into a mode of the film. Scatter in the film provides a mechanism for excitation of neighbouring modes, and the net result is an m-line display as illustrated in Fig. 1(left). The characteristic (Snell’s law) value β = n sin θ is measured for several modes and the principal indices can be determined by matching calculated and experimental modal patterns.

© 1995 Optical Society of America