硅波导纵向多模式分离与交叉的片上解决方案

为了解决硅纳米光子集成器件中纵向分布多模式波导的分离和交叉，提出了一种基于平面阶梯光栅和非对称定向耦合器的模式分离方案，并设计了一种带有曲面反射镜的器件，可实现多模式同时交叉.通过使用三维时域有限差分方法对器件进行仿真，结果表明:设计的平面阶梯光栅可同时分离不同的波长及模式(共9个通道)，并具有低于-30 dB的串扰；曲面反射模式交叉器件可同时让3个模式进行交叉，且对所有模式均具有接近-40 dB的低串扰.

The On-Chip Solutions to Mode Separation and Crossing of Vertical Multi-Modes in Silicon Waveguide

Solutions to mode separation and crossing of vertically distributed multi-modes inside silicon nanophotonic integrated devices are investigated. Mode demultiplexers based on both echelle gratings and asymmetric directional couplers are demonstrated. A device with curved reflectors which allows multi-modes to cross simultaneously is also designed. The simulation results based on the 3D Finite-Difference Time-Domain methods show that the echelle grating allows altogether 9 channels of different modes and wavelengths to be separated with crosstalks no more than -30 dB. The curved reflectors works properly for crossings of three modes, and the crosstalks are merely around -40 dB.