Ye Chaochao, Zhang Ming, Shi Yaocheng, Dai Daoxin
Appl Opt. 2020 Aug 20;59(24):7308-7312. doi: 10.1364/AO.397676.
A broadband dual-mode 2×23 power splitter on silicon is proposed by utilizing multimode interference (MMI) couplers with a shallowly etched multimode region. The present MMI coupler is designed optimally to be with reduced phase errors for all the excited higher-order modes in the MMI region by engineering the refractive-index profile with the assistance of a shallowly etched multimode region. Simulation results show the device works well for the and input modes over the C-band. For the input mode, the excess losses (ELs) and the imbalances (IBs) are, respectively, less than 0.4 and 0.12 dB in the wavelength range of 1.5-1.6 µm, while the ELs and the IBs for the input mode are, respectively, less than 0.5 and 0.2 dB in the wavelength range of 1.53-1.58 µm. Besides, the intermode cross-talk is less than -22 for and modes in the wavelength range of 1.5-1.6 µm. The proposed dual-mode MMI coupler can be extended for more than two input modes.
通过利用具有浅蚀刻多模区域的多模干涉（MMI）耦合器，提出了一种基于硅的宽带双模2×2 3功分器。当前的MMI耦合器经过优化设计，通过在浅蚀刻多模区域的辅助下设计折射率分布，以减少MMI区域中所有激发高阶模的相位误差。仿真结果表明，该器件在C波段对TE₀₀和TE₀₁输入模式工作良好。对于TE₀₀输入模式，在1.5 - 1.6 µm波长范围内，额外损耗（ELs）和不平衡度（IBs）分别小于0.4 dB和0.12 dB，而对于TE₀₁输入模式，在1.53 - 1.58 µm波长范围内，ELs和IBs分别小于0.5 dB和0.2 dB。此外，在1.5 - 1.6 µm波长范围内，TE₀₀和TE₀₁模式的模间串扰小于 -22 dB。所提出的双模MMI耦合器可扩展到两个以上的输入模式。
