Document Type
Article
Publication Date
4-15-1985
Abstract
Given a transparent film of refractive index n1 on an absorbing substrate of complex refractive indexn2-jk2, we examine the constraint on n1, n2, and k2 such that the film-substrate system acts as an external-reflection retarder of specified retardance Δ at a specified angle of incidence φ. The constraint, which takes the form ƒ(n1,n2,k2;φ,Δ) = 0, is portrayed graphically by equi-n1 contours in the n2,k2 plane at φ = 45, 70° and for Δ = ±90 and ±180°, corresponding to quarterwave and halfwave retarders (QWR and HWR), respectively. The required film thickness as a fraction of the film thickness period and the polarization-independent device reflectance R are also studied graphically as functions of the optical constants. It is found that as n2 → 0, R → 1, so that a metal substrate such as Ag is best suited for high-reflectance QWR (φ > 45°) and HWR (φ ≤ 45°). However, films that achieve QWR at φ ≤ 45° are excellent antireflection coatings of the underlying dielectric, semiconductor, or metallic substrate.
Journal Name
Applied Optics
Recommended Citation
R. M. A. Azzam and Bruce E. Perilloux, "Constraint on the optical constants of a film-substrate system for operation as an external-reflection retarder at a given angle of incidence," Appl. Opt. 24, 1171-1179 (1985)
Comments
This paper was published in Applied Optics and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-24-8-1171. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.