Thin-film grating polarizer

The deexcitation of guided modes in a thin-film planar dielectric waveguide is considered. On the film-cover interface is etched an ordinary diffraction grating whose wave number is such that one radiation beam in the substrate alone is generated. For a specified radiation direction the p-polarized radiation vanishes selectively. This phenomenon is used in the development of a polarizer whose output is predominantly in the p polarization. The sensitivity of the performance of the polarizer to small deviations in the design parameters is also investigated.