Empirical equations for the principal refractive indies and column angle of obliquely deposited films of tantalum oxide, titanium oxide, and zirconium oxide

摘要

Values of the transmittance T↓(s) and the phase retardation a were recorded in situ at two angles during the growth, of thin rims of tantalum oxide, titanium oxide, and zirconium oxide for deposition angles 0, in the range40°-70°. Column angles for the same films were determined ex situ from scanning electron microscopy photographs of deposition-plane fractures. We show that the experimental column angles are smaller than the corresponding values predicted by the tangent-rule equation#= tan↑(-l)(0.5 tan θ↓(v)) and that the experimental values fit a modified form of the equation#= tan↑(-l)(E↓(1) tan θ↓(v)) where E↓(1) is less than 0.5. We also show that the principal refractive indices are represented well by quadratic functions of the deposition.angle, for example, n↓(v)(θ↓(v)) = A↓(θ) + A↓(2) θ↓(v)↑(2),#1998 Optical Society of America OCIS codes: 310.0310, 310.1620, 260.1440.