Vacuum deposited biaxial thin films with all principal axes inclined to the substrate

We begin by considering the three effective principal refractive indices and the effective axes of a periodic layered medium in which the component layers are tilted- columnar biaxial films formed by vacuum deposition in different planes. A parameter window within which the effective principal refractive indices are well separated and all three effective axes are inclined to the substrate is found for titanium oxide. Next, a set of parameters from the window is transported directly to the regime of bideposition, in which nanometer-scale subdeposits of the components are made serially as starting values for the automated growth of inclined biaxial media. Finally index values and angles are estimated for three samples, using an optimization technique in which experimental and computed angular phase retardance maps are matched.