Huang Tianye, Xie Yuan, Wu Yiheng, Cheng Zhuo, Zeng Shuwen, Ping Perry Shum
Appl Opt. 2019 Mar 20;58(9):2264-2268. doi: 10.1364/AO.58.002264.
A polarization beam splitter (PBS) is one of the key components for manipulating different polarization states in the areas of optical interconnection and communication. In this paper, a PBS with two coupling regions using a subwavelength grating (SWG) waveguide as a bridge is proposed and investigated on a 340-nm silicon-on-insulator platform. The PBS is designed with a triple-waveguide directional coupler consisting of two identical silicon waveguides and an SWG waveguide sandwiched between them. The tailorable dispersion relation of the SWG waveguide offers a flexible design freedom. With the optimized grating period and duty ratio, the input TE mode will experience efficient coupling between the silicon waveguide and the SWG waveguide, while the TM mode can directly pass through without influence. The results show that with a device length of 6.5 μm, the extinction ratios and insertion losses of the two modes are higher than 27 dB and lower than 0.3 dB at a wavelength of 1550 nm, respectively.
偏振分束器（PBS）是光互连和通信领域中用于操控不同偏振态的关键组件之一。本文在340纳米绝缘体上硅平台上提出并研究了一种采用亚波长光栅（SWG）波导作为桥梁的具有两个耦合区域的PBS。该PBS设计为一个三波导定向耦合器，由两个相同的硅波导和夹在它们之间的一个SWG波导组成。SWG波导可定制的色散关系提供了灵活的设计自由度。通过优化光栅周期和占空比，输入的TE模式将在硅波导和SWG波导之间实现高效耦合，而TM模式可以直接通过而不受影响。结果表明，在器件长度为6.5微米时，两种模式在1550纳米波长下的消光比分别高于27分贝，插入损耗分别低于0.3分贝。
