High extinction ratio antiresonant reflecting optical waveguide-type polarizers with large core diameter

An optical polarizer based on antiresonant reflecting optical waveguide (ARROW) structure is presented. The advantage over conventional ARROW devices is the fact that high extinction ratio of the proposed polarizer can be obtained even with a large core diameter. This comes into effect because loss discrimination against TM modes is dramatically enhanced due to birefringence of the polyimide core. In addition, the loss discrimination can be further increased by reducing the thickness of the core at the first antiresonant condition. The measured extinction ratio and insertion loss of a 2-cm-long polyimide∕Ta2O5∕SiO2 ARROW polarizer are 40dB and 2.2dB, respectively.