title: Ultrashort broadband polarization beam splitter based on an asymmetrical directional coupler.
abstract: An ultrashort polarization beam splitter (PBS) based on an asymmetrical directional coupler is proposed by utilizing the evanescent coupling between a strip-nanowire and a nanoslot waveguide. In order to be convenient for integration with other components, mode converters between the nanoslot waveguide and the strip-nanowire are introduced and merged into S-bends to achieve an ultracompact PBS. As an example a 6.9 μm long PBS based on a silicon-on-insulator platform is designed, and the length of the coupling region is as small as 1.3 μm. Numerical simulations show that the present PBS has a very broad band (>160 nm) for an extinction ratio of >10 dB.
authors: University of California Santa Barbara, ECE Department, Santa Barbara, California 93106, USA. dxdai@ece.ucsb.edu
authors: Daoxin
authors: D
authors: Dai
authors: Zhi
authors: Z
authors: Wang
authors: John E
authors: JE
authors: Bowers