On the Motohiro-Taga interface for biaxial columnar media

The optical response of a Motohiro-Taga biaxial interface (MTBI) that separates two biaxial columnar thin films is explored analytically as well as computationally. Empirical equations based on experimental measurements of the principal effective refractive indices and the columnar inclination angle enable characteristic reflectances to be computed for MTBIs made of titanium oxide. Null-reflection conditions occur for any equicolumnar MTBI (EMTBI) wherein identical columns are inclined at equal angles but on opposite sides of the normal. Then all reflectances at the EMTBI are zero for light obliquely incident in the common deposition plane, but both co- and cross-polarized reflection occur for light obliquely incident in any other plane.