The cumulative retardance introduced between the p and the s orthogonal linear polarizations after two successive total internal reflections (TIRs) inside a right-angle prism at complementary angles ϕ and is calculated as a function of ϕ and prism refractive index n. Quarter-wave retardation (QWR) is obtained on retroreflection with minimum angular sensitivity when and . A QWR prism made of N-BAK4 Schott glass ( at ) has good spectral response ( retardance error) over the 0.5– visible and near-IR spectral range. A ZnS-coated right-angle Si prism achieves QWR with an error of in the 9– ( laser) IR spectral range. This device functions as a linear-to-circular polarization transformer and can be tuned to exact QWR at any desired wavelength (within a given range) by tilting the prism by a small angle around . A PbTe right-angle prism introduces near-half-wave retardation (near-HWR) with a error over a broad IR spectral range. This device also has a wide field of view and its interesting polarization properties are discussed. A compact (aspect ratio of 2), in-line, HWR is described that uses a chevron dual Fresnel rhomb with four TIRs at the same angle . Finally, a useful algorithm is presented that transforms a three-term Sellmeier dispersion relation of a transparent optical material to an equivalent cubic equation that can be solved for the wavelengths at which the refractive index assumes any desired value.
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