ARROW-type polarizer with large core diameter and high extinction ratio

An optical polarizer based on antiresonant reflecting optical waveguide (ARROW) structure is proposed. 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 size. This is accomplished by tuning the operating point of the transverse-magnetic (TM₀) mode from antiresonant condition toward high-order antiresonance of the second cladding layer utilizing birefringence of the waveguide core. For polyimide-Ta₂O₅-SiO₂ ARROW polarizer with 7.1-μm-thick core, an extinction ratio larger than 40 dB has been experimentally achieved. The transverse-electric insertion loss and propagation loss of the polarizer at a wavelength of 1.31 μm are 2.5 dB and 0.44 dB/cm, respectively.