A Novel Nano-Grating Structure of Polarizing Beam Splitters

A metal wire nanograting is fabricated and used as a polarizing beam splitter that reflects TE polarization and transmits TM polarization. The metal wire nanograting is based on a fully optimized design structure that consists of not only the core nanowire metal grid but also the substrate nanograting. The substrate nanograting is designed to provide better performance for both TM and TE polarizations. We fabricate metal-stripe gratings on a glass substrate using nanoimprint lithography and reactive ion etching process. A detailed investigation of the polarization effect at 1550nm wavelength is carried out with the theoretical analysis and experimental results. The polarizing beam splitter has uniform performance with wide variations in the incident angle (±25) and has high efficiency for both the reflected and the transmitted beams.