On-Chip Multi-Mode Manipulation via 2D Refractive-Index Perturbation on a Waveguide

摘要

Generation and manipulation of optical modes are of general interest to the photonics community. Mode conversion is an essential requirement in mode-division multiplexed systems. In this paper, a scalable method to simultaneously manipulate multiple waveguide modes on chip is proposed. As one experimental demonstration, simultaneous multi-mode conversion processes have been achieved on a waveguide. The device is realized via an all-dielectric 2D structure on the silicon waveguide by shallow etching with hexagonal patterns. In the experiment, the device simultaneously converts the TE(i)modes to the TEi+3(i = 0, 1, and 2) modes. The length of the multi-mode converter is 16.2 mu m. The TE0-TE3, TE1-TE4, and TE2-TE(5)mode conversion processes exhibit low insertion losses (0.4 to 1.0 dB) and reasonable crosstalk values (-14.1 to -16.5 dB) at 1538 nm. The scalability of the converter is also verified by simulations.