Abstract
The p- and s-polarized components of light can be suppressed on reflection at the same angle of incidence from an absorbing substrate coated by a transparent thin film if the wave is refracted in the film at 45° and the constraint Re[(∊2 − α)/(1 − α)]1/2 = α + |∊2 − α| is satisfied, where 2α and ∊2 are the ratios of dielectric constants of the film and substrate, respectively, to that of the ambient. For high-reflectance metal substrates (|∊2| ≫ 1), α ≃ 1, the ratio of film to ambient refractive index approaches , and the unextinguished reflectances approach 1. The least film thicknesses required to suppress the p and s polarizations are in the ratio 2:1. The analysis is applied to Si and Al substrates in the near UV-visible-near-IR spectral range. It is found that the film refractive index and thickness should be controlled to within ±0.01 and ±5 Å, respectively, for an Al substrate at 550 nm. Significant applications are proposed that include parallel-mirror crossed polarizers, a novel polarimeter that integrates the polarization-analysis and photodetection functions, high-reflectance crossed thin-film reflection polarizers integrated on the same substrate, and division-of-wavefront polarizing beam splitters.
© 1985 Optical Society of America
Full Article | PDF ArticleMore Like This
R. M. A. Azzam
Appl. Opt. 24(4) 513-518 (1985)
R. M. A. Azzam and Karim Javily
Appl. Opt. 24(4) 519-526 (1985)
M. Ruiz-Urbieta and E. M. Sparrow
J. Opt. Soc. Am. 62(10) 1188-1194 (1972)