Design Principles for Quarter-Wave Retarders that Employ Total Internal Reflection and Light Interference in a Single-Layer Coating

Explicit equations are derived for the design of quarter-wave retarders (QWR) that exploit total internal reflection (TIR) and interference of light in a transparent thin-film coating at the base of a prism. The optimal refractive index and normalized thickness of QWR coatings on glass and ZnS prisms are determined as functions of the internal angle of incidence from 45° to 75°. An achromatic retarder that uses TIR by a Si3N4-coated NBK10- Schott glass prism is also presented that achieves exact QWR at two wavelengths (409 and 500 nm) and exhibits a retardation error of 1.5° for wavelengths 375 ≤ λ ≤ 550 nm in the near-UV and the violet-blue-green part of the visible spectrum.