Open AccessVertically-integrated multimode interferometer coupler for 3D photonic circuits in SOI
Author(s) -
Chris Brooks,
Andrew P. Knights,
P. E. Jessop
Publication year - 2011
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.19.002916
Subject(s) - silicon on insulator , waveguide , materials science , multi mode optical fiber , optics , photonic integrated circuit , optoelectronics , interferometry , silicon photonics , photolithography , coupling loss , photonics , coupling (piping) , etching (microfabrication) , silicon , optical fiber , physics , nanotechnology , layer (electronics) , metallurgy
Vertical optical coupling is demonstrated in a multimode interferometer structure fabricated using silicon-on-insulator (SOI) material. These CMOS-compatible couplers are suitable to be used to transfer optical power between stacked waveguide layers of a three-dimensional photonic circuit. Coupling between these layers can be restricted to certain regions by selectively fabricating a silicon channel between them, resulting in an isolated multimode waveguide section. Standard photolithography and etching techniques were used to fabricate proof-of-concept devices consisting of a channel waveguide coupling into a silicon waveguide that is vertically multimode. An optical coupling ratio of 93±4% between the upper and lower waveguide regions of the device was achieved with a coupler length of 241 µm.