University of California Santa Barbara, ECE Department, Santa Barbara, California 93106, USA.
Opt Lett. 2011 Jul 1;36(13):2590-2. doi: 10.1364/OL.36.002590.
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.
一种基于不对称定向耦合器的超短偏振分光器（PBS），通过利用条形-纳米线和纳米槽波导之间的消逝场耦合来实现。为了便于与其他组件集成，在纳米槽波导和条形-纳米线之间引入模式转换器，并将其合并到 S 型弯曲中，以实现超紧凑的 PBS。例如，在绝缘体上硅平台上设计了一个 6.9μm 长的 PBS，其耦合区长度只有 1.3μm。数值模拟表明，该 PBS 的消光比大于 10dB 的带宽非常宽（>160nm）。
