ARROW-B Type Polarization Splitter with Asymmetric Y-Branch Fabricated by a Self-Alignment Process

We have proposed and demonstrated a polarization splitter based on an ARROW-B type waveguide. This device has an asymmetric Y-branch configuration, connecting a waveguide with a large modal birefringence to a low-birefringent waveguide which is channeled by the stripe lateral confinement structure. The device can achieve a high extinction ratio without precise mask alignment, since these two waveguides are connected by self-alignment process. In addition, a low insertion loss is achieved because of adiabatic Y-branching. We designed this device at the wavelength of 1.55 m and fabricated using an RF sputtering. As the result, high extinction ratios of 19.4 dB for TE mode and 19.0 dB for TM mode were achieved.