Optical nanostructures have the potential to provide useful new functionalities, using materials and fabrication methods that are compatible with standard silicon-based processes. For example, it has been shown that a nanoscale grating coated with a metal layer produces polarization-selective reflectivity [1,2], based on the combined effects of form birefringence and a resonant cavity [3]. In this work, we adapt this design approach to develop two devices optimized to operate around 1.55 μm wavelength: a polarizing beam splitter, and a polarization-selective reflector. Such devices are of particular interest as they may provide optical properties such as polarization selectivity or enhanced reflectivity using nanostructures compatible with optical micro-electro-mechanical systems (MEMS).