Document Type

Article

Publication Date

7-6-2007

Abstract

A centrosymmetric multilayer stack of two transparent thin-film materials, which is embedded in a high-index prism, is designed to function as an efficient polarizer or polarizing beam splitter (PBS) under conditions of frustrated total internal reflection over an extended range of incidence angles. The S(LH)kLHL(HL)kS multilayer structure consists of a high-index center layer H sandwiched between two identical low-index films L and high-index-low-index bilayers repeated (k times) on both sides of the central trilayer maintaining the symmetry of the entire stack. For a given set of refractive indices, all possible solutions for the thicknesses of the layers that suppress the reflection of p-polarized light at a specified angle, and the associated reflectance of the system for the orthogonal s polarization, are determined. The angular and spectral sensitivities of polarizing multilayer stacks employing 3, 7, 11, 15, and 19 layers of BaF2 and PbTe thin films embedded in a ZnS prism, operating at λ=10.6 μm, are presented. The 15- and 19-layer stack designs achieve extinction ratios (ER) >30 dB in both reflection and transmission over a 46°-56° field of view inside the prism. Spectral analysis reveals additional discrete polarizing wavelengths other than the design wavelength (λ=10.6 μm). The 11-, 15-, and 19-layer designs function as effective s-reflection polarizers (|Rs|2>99%) over a 2-3 μm bandwidth. The effect of decreasing the refractive index contrast between the H and L layers on the resulting ER is also considered.

Journal Name

Applied Optics

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-46-21-4604. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.

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