We report on an ultra-compact, low loss and broadband TM-pass polarizer, which is constructed by two interleaved subwavelength-gratings (SWGs) waveguides inserted in the center of the strip waveguide on a silicon-on-insulator (SOI) platform. The device structure is optimally engineered to support Bloch mode for fundamental TM polarization only. Therefore, the TM mode transmits along the strip waveguide with rather low propagation loss while the TE mode is completely reflected by the embedded SWGs waveguides. Simulation results show that an efficient and ultra-compact TM-pass polarizer of 5.2 μm in length is realized with extinction ratio (ER) of 31.63 dB and insertion loss (IL) of 0.18 dB at the operating wavelength of 1550 nm. The operation bandwidth for ER over 20 dB and IL below 0.32 dB is 155 nm (from 1465 to 1620 nm). By increasing the period number, the ER performance and bandwidth can be further improved. Furthermore, the fabrication of the present polarizer only requires mono-lithography and single etch process, which will greatly reduce the fabrication difficulty.

中文翻译：

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SOI平台上基于交错亚波长光栅条形波导的TM通偏振器

我们报告了一种超紧凑、低损耗和宽带 TM 通偏振器，它由插入绝缘体上硅 (SOI) 平台上条形波导中心的两个交错亚波长光栅 (SWG) 波导构成。器件结构经过优化设计，仅支持基本 TM 极化的 Bloch 模式。因此，TM 模式沿带状波导传输，传播损耗相当低，而 TE 模式完全被嵌入的 SWGs 波导反射。仿真结果表明，实现了长度为 5.2 μm 的高效超紧凑型 TM-pass 偏振器，在 1550 nm 工作波长下消光比 (ER) 为 31.63 dB，插入损耗 (IL) 为 0.18 dB。ER 超过 20 dB 和 IL 低于 0.32 dB 的操作带宽为 155 nm（从 1465 到 1620 nm）。通过增加周期数，可以进一步提高 ER 性能和带宽。此外，本偏光片的制作仅需单光刻和单次刻蚀工艺，大大降低了制作难度。