Photonics Research Group Home
Ghent University Doctoral Theses
About People Research Publications Education Services


PhD. of Samir Ghosh

Author: Samir Ghosh
Promotors: Roel Baets and Gunther Roelkens
Dutch Title: Optische isolatoren in fotonische geïntegreerde schakelingen op basis van silicium
English Title: Optical Isolators in Silicon Based Photonic Integrated Circuits
Date: 26/8/2013
Main Language: English
ISBN number: 978-90-8578-618-4
Thesis: Download the PhD Thesis (12.2MB) (12.2MB)


The performance of semiconductor lasers used in optical communication system is very sensitive to back reflections. In order to stabilize the performance of laser an optical isolator is typically required. An isolator is a device which allows light in one direction always. The commercially available bulk isolator is based on the polarization rotation of incident light when light passing through a block of longitudinally magnetized ferrimagnetic Yttrium Iron Garnet (YIG). Due to advances in integrated optics many bulk optical components have already been realized on integrated platforms. One of the emerging platforms is the Silicon-on-Insulator (SOI) platform. The goal of this work was to demonstrate an optical isolator based on the SOI waveguide circuit. Two different routes were adopted to integrate magnetic material on top of SOI circuit such as adhesive bonding and direct sputtering deposition. A piece of garnet material is adhesively bonded on top of the SOI circuit by means of a polymer called Benzocylcobutene (BCB). Different types of optical isolators have been demonstrated using the BCB bonding technique. The sputtering deposition technique was also investigated upto some extent although more further research is still required in this field.

Back to list