An ultrawideband polarization rotator (PR) with low insertion loss (IL) based on silicon on insulator (SOI) platform is proposed. The input TM0 / TE0-polarized modes can be rotated 90 deg simultaneous using a 45-deg W-slot dual-stair waveguide with varied width. Simulation results show that with a PR in length of 4.3 μm, the IL is below 0.4 (0.42) dB and polarization extinction ratio (PER) is over 17 (16) dB for TE0-to-TM0 (TM0-to-TE0) mode conversion within bandwidth of 300 nm (from 1400 to1700 nm), which covers optical fiber communication S-, C-, L-, and U-bands. In addition, the fabrication tolerance is analyzed numerically. The proposed PR has excellent performance with compact footprint and will find potential application in large-scale high-performance PICs.

中文翻译：

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基于覆盖 S + C + L + U 波段的 45 度 W 槽双阶梯波导的超宽带偏振旋转器

提出了一种基于绝缘体上硅 (SOI) 平台的具有低插入损耗 (IL) 的超宽带极化旋转器 (PR)。输入 TM0 / TE0 偏振模式可以使用宽度不同的 45 度 W 槽双阶梯波导同时旋转 90 度。仿真结果表明，对于 TE0-to-TM0 (TM0-to-TE0) 模式，当 PR 长度为 4.3 μm 时，IL 低于 0.4 (0.42) dB，偏振消光比 (PER) 超过 17 (16) dB 300nm（从1400到1700nm）带宽内的转换，涵盖光纤通信的S-、C-、L-和U-波段。此外，还对制造公差进行了数值分析。所提出的 PR 具有出色的性能和紧凑的占用空间，并将在大规模高性能 PIC 中找到潜在的应用。