Silicon-based polarization optics for the 1.30 and 1.55 mu m communication wavelengths

A modular three-reflection prism of Si can be designed to function as an in-line (nondeviating) linear polarizer or quarterwave retarder at the 1.30 and 1.55 mu m lightwave communication wavelengths. Si-related thin films are employed as optical coatings. In particular, a single-layer antireflection coating of Si3N4 is used at the entrance and exit faces, and a SiO2 film controls the polarization and total internal reflection phase shifts at the side surfaces of the prism. The angular and wavelength sensitivity of these proposed Si-based polarization optical elements is also considered.