Open AccessSub-wavelength grating components for integrated optics applications on SOI chips
Author(s) -
Valentina Donzella,
Ahmed Sherwali,
Jonas Flueckiger,
Sahba Talebi Fard,
Samantha M. Grist,
Lukas Chrostowski
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.021037
Subject(s) - power dividers and directional couplers , silicon on insulator , materials science , optics , grating , cladding (metalworking) , resonator , optoelectronics , wavelength , waveguide , fabrication , astronomical interferometer , bandwidth (computing) , interferometry , silicon , physics , telecommunications , medicine , alternative medicine , pathology , computer science , metallurgy
In this paper we demonstrate silicon on insulator (SOI) sub-wavelength grating (SWG) optical components for integrated optics and sensing. Light propagation in SWG devices is studied and realized with no cladding on top of the waveguide. In particular, we focused on SWG bends, tapers and directional couplers, all realized with compatible geometries in order to be used as building blocks for more complex integrated optics devices (interferometers, switches, resonators, etc.). Fabricated SWG tapers for TE and TM polarizations are described; they allow for connecting SWG devices to regular strip waveguides with loss lower than 1 dB per taper. Our SWG directional coupler presents a very compact design and a negligible wavelength dependence of its crossover length (and as a consequence of its coupling coefficient, κ), over a 40 nm bandwidth. This wavelength flatten response represents a bandwidth enhancement with respect to standard directional couplers (made using strip or rib waveguides), in particular for the TE mode. SWG bends are demonstrated, their loss dependence on radius is analyzed, and fabricated bends have a loss in the range 0.8-1.6 dB per 90 degrees bend. Simulated and measured results show promise for large-scale fabrication of complex optical devices and high sensitivity sensors based on SWG waveguides with engineered optical properties, tailored to specific applications.