Study of polarization diversity circuit in silicon photonics

• Main Author: Lee, Tze Jun.
• Other Authors: Shum Ping
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
• Online Access: http://hdl.handle.net/10356/15805
• Institution: Nanyang Technological University

A light source can be broken down into its electric field vectors; the Transverse Electric (TE) and the Transverse Magnetic (TM). Structural birefringence causes the high frequency TE and TM waves to travel at different speeds. This causes the waves to arrive at their destinations with a phase difference resulting in loss of power or bit error rate in data transmissions. Hence, current optical circuits are limited to a frequency of 40Gbps. In order to overcome the problem of different phase velocity of the TE and TM, a single light source is separated into its TE and TM components and treated separately before combining at the output using a polarization splitter and rotator. This ensures that the TE and TM waves arrive at the output in phase and having experienced the same amount of loss. This report documents the study, design and testing of a polarization splitter and rotator. Many splitter and rotator designs have been proposed to achieve polarization diversity in silicon photonics circuit. In this project, we aim to create a polarization diverse circuit by analysing the pros and cons of current designs by Nippon Telegraph & Telephone Corporation (NTT), Massachusetts Institute of Technology (MIT) and Zhejiang University, and thereby further improving current polarization splitter and rotator designs.