Optical 90° Hybrid using 2x4 MMI for Coherent Optical Communication System

Coherent optical communication systems have many options in schemes of multilevel modulation and compensation of transmission related impairments in silicon photonics technology. Silicon photonics is a propitious technology which allows designing devices in compact space and at cheaper price. 2 x 4 90° hybrid is a major component in an in phase/Quadrature Phase (IQ) coherent receiver. High yielding silicon photonics technology with the Complementary Metal Oxide Semiconductor technology gives an opportunity to design devices for low cost which gives photonics electronics integration. This paper presents a 2 x 4 multimode interferometer based optical 90° hybrid in silicon on insulator (SOI) platform and its practical implementation.