Three-mode multiplexer and demultiplexer utilizing trident and multimode couplers

Abstract

In this paper, a simultaneous three-mode silicon (de)multiplexer using a trident coupler and a 3 x 3 multimode interference (MMI) is presented. The fundamental (TE0), first-order (TE1), and second-order (TE2) modes at the input are successfully demultiplexed and converted to three uniform fundamental modes (TE0) at the output ports. The device is designed and optimized by numerical simulation using three-dimensional beam propagation method together with effective index method. The three-mode (de)multiplexing is achieved over the whole C-band with small insertion loss ( dB) and crosstalk ( dB). The proposed device also features with a small footprint ( ) and a large fabrication tolerance against chip-size variations while maintaining the desired optical performance.