基于混合表面等离子体弯曲波导的紧凑型宽带偏振分束转换器的设计研究

设计了一种宽带的基于混合表面等离子体弯曲波导的偏振分束转换器, 使用有限元法计算硅波导、混合表面等离子体波导的模场分布和有效折射率, 为器件建模仿真分析提供了依据. 使用时域有限差分法优化器件结构, 以获得最佳的性能参数. 由于混合表面等离子体波导的双折射增强, 设计获得的偏振分束转换器具有超小尺寸和宽带的工作特性. 仿真结果表明 在1550nm的中心波长处消光比大于23dB, 插入损耗小于0.8dB; 在80nm的带宽上, 横磁偏振光转换为横电偏振光的偏振转换效率大于95％.

Compact broadband plasmonic-assisted polarization splitter-rotator based on bent directional couplers

We propose a plasmonic-assisted polarization splitter-rotator (PSR) based on bent directional couplers. The finite element method is used to calculate the mode field distribution and effective refractive index of silicon waveguides, as well as hybrid surface plasmon waveguides, all of which provide an important basis for device modeling and analysis. We simulate light propagation in the proposed device by a three-dimensional finite-difference time-domain method. With the enhanced birefringence resulting from the plasmonic-assisted asymmetry, the present PSR features ultra-compact size and broadband operation. Our simulation results show an extinction ratio greater than 23dB and an insertion loss lower than 0.8dB at the central wavelength of 1550nm. The TM-to-TE polarization conversion efficiency is improved by more than 95% over a bandwidth of 80nm.