Surface waves at a biaxial bicrystalline interface.

Localized to the planar interface of two identical dielectric biaxial crystals with optic ray axes parallel to the interface but with a relative twist about an axis perpendicular to the interface, electromagnetic wave propagation along the bisectrix of the two crystallographic orientations is possible with either real-valued or complex-valued transverse decay constants as the twist angle varies from 0 degrees to an upper limit (< or =90 degrees) that is dependent on the angle between the two optic ray axes.

Surface waves with simple exponential transverse decay at a biaxial bicrystalline interface.

The dispersion equation for surface waves--with simple transverse exponential decay at the interface of identical biaxial crystals with a relative twist about the axis normal to the interface and propagating along a bisector of the angle between the crystallographic configurations on either side of the interface--has several solutions of which only one is physical. The selected type of surface wave is possible only for a restricted range of the twist angle, which depends on the ratio of the maximum and the minimum of the principal refractive indexes and the angle between the optic ray axes.