title: Realization of an ultra-short silicon polarization beam splitter with an asymmetrical bent directional coupler.
abstract: An ultra-short (~10 μm long) polarization beam splitter (PBS) based on an asymmetrical bent directional coupler (DC) is demonstrated experimentally by using silicon-on-insulator nanowires. The bent DC is designed to cross-couple TM polarized light completely while there is almost no coupling for TE polarization. Grating couplers are introduced at both ends of the PBS for efficient coupling to single-mode fibers. The measurement results show that the extinction ratios of the fabricated ultra-short PBS are higher than 10 dB for both polarizations in a broad wavelength range. It is also shown that the present PBS has a large fabrication tolerance.
authors.affiliation: Centre for Optical and Electromagnetic Research, State Key Laboratory for Modern Optical Instrumentation, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Di
authors.initials: D
authors.lastname: Liang
authors.forename: Yongbo
authors.initials: Y
authors.lastname: Tang
authors.forename: Daoxin
authors.initials: D
authors.lastname: Dai
authors.forename: John E
authors.initials: JE
authors.lastname: Bowers