Multimode interference isolator on Silicon-on-Insulator platform

Abstract

This paper presents the design of a multimode interference(MMI) based optical isolator on Silicon-On-Insulator (SOI) structure, by using the magneto-optical (MO) nonreciprocal phase shift (NRPS) of an MO thin film cladding on silicon waveguides. Finite element method (FEM) simulation based on coupled mode theory is applied to calculate the performance of the isolator. An isolator with isolation ratio of 25.8 dB, 20 dB bandwidth of 1.6 nm and insertion loss of 5.4 dB, considering all material and junction losses can be achieved in the proposed device at around 1550 nm wavelength.