Contours of Constant Principal Angle in the Complex Dielectric Plane

The contours of the constant principal angle in the complex dielectric plane can be determined by eliminating the principal azimuth from the equation . This gives , which is a circle with center at on the real axis and radius . The figure shows constant principal-angle contours for . As approaches , these contours approach concentric circles with center at .

The usual notation for the principal angle, , and principal azimuth, , has been modified for visual clarity.

R. M. A. Azzam, "Contours of constant principal angle and constant principal azimuth in the complex ϵ plane," Journal of the Optical Society of America, 71(12), 1981 pp. 1523-1528.