Table of Contents
Advances in Optical Technologies
Volume 2008 (2008), Article ID 685489, 8 pages
http://dx.doi.org/10.1155/2008/685489
Research Article

Subwavelength Grating Structures in Silicon-on-Insulator Waveguides

Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, ON, Canada K1A 0R6

Received 20 December 2007; Revised 24 April 2008; Accepted 28 May 2008

Academic Editor: Graham Reed

Copyright © 2008 J. H. Schmid et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

First implementations of subwavelength gratings (SWGs) in silicon-on-insulator (SOI) waveguides are discussed and demonstrated by experiment and simulations. The subwavelength effect is exploited for making antireflective and highly reflective waveguide facets as well as efficient fiber-chip coupling structures. We demonstrate experimentally that by etching triangular SWGs into SOI waveguide facets, the facet power reflectivity can be reduced from 31% to <2.5%. Similar structures using square gratings can also be used to achieve high facet reflectivity. Finite difference time-domain simulations show that >94% facet reflectivity can be achieved with square SWGs for 5  𝜇 m thick SOI waveguides. Finally, SWG fiber-chip couplers for SOI photonic wire waveguides are introduced, including design, simulation, and first experimental results.