设计了一种采用锥形渐变不对称耦合结构的模式复用/解复用器, 并利用商用的0.18 μm互补金属氧化物半导体兼容工艺进行制备.通过控制锥形波导的宽度, 基于模式有效折射率匹配原则, 实现锥形波导中的基模与多模波导中的高阶模式相互转化.测试结果表明: 当器件用于TE0、TE1和TE2三个模式复用与解复用时, 在1 530 nm到1 570 nm波长范围内, 串扰低于-8.05 dB；而当器件复用与解复用TE0和TE2时, 串扰低于-16.43 dB.

In this paper, we design and demonstrate a mode (de)multiplexer using tapered couplers on a silicon-on-insulator substrate by commercial 0.18 μm complementary metal-oxide-semiconductor compatible processes. By controlling the width of a tapered waveguide, the mutual conversion between the fundamental mode in the tapered waveguide and the high-order mode in the multimode straight waveguide can be realized due to the matching of modal effective indexes. For the multiplexing and demultiplexing of the TE0, TE1 and TE2 modes, the fabricated device, which is composed of a mode multiplexer, a multimode straight waveguide, and a mode demultiplexer, exhibits crosstalk lower than -8.05 dB within a bandwidth from 1 530 nm to 1 570 nm. The crosstalk is less than -16.43 dB for the multiplexing and demultiplexing of the TE0 and TE2 modes.