A single-lithography SOI rib waveguide sensing circuit with apodized low back-reflection surface grating fiber coupling
2012 (English)In: SILICON PHOTONICS AND PHOTONIC INTEGRATED CIRCUITS III / [ed] Laurent Vivien, Seppo K. Honkanen, Lorenzo Pavesi, Stefano Pelli, SPIE - International Society for Optical Engineering, 2012, Vol. 8431, 84311-84311 p.Conference paper (Refereed)
We present a single-lithography Mach-Zehnder interferometer sensor circuit, with integrated low back-reflection input and output grating couplers. The low back-reflection is accomplished by a duty cycle apodization optimized for coupling light between single-mode silica fibers and the nanometric silicon-on-insulator (SOI) rib-waveguides. We discuss the design, fabrication, and characterization of the circuit. The apodization profile of the gratings is algorithmically generated using eigenmode expansion based simulations and the integrated waveguides, splitters, and combiners are designed using finite element simulations. The maximum simulated coupling efficiencies of the gratings are 70% and the multimode interference splitters and combiners have a footprint of only 19.2ï¿œ4.5 ï¿œm2. The devices are fabricated on an SOI wafer with a 220 nmdevice layer and 2 ï¿œm buried oxide, by a single electron beam lithography and plasma etching. We characterize the devices in the wavelength range from 1460-1580 nm and show a grating pass-band ripple of only 0.06 dB and grating coupling efficiency of 40% at 1530 nm. The integrated Mach-Zehnder interferometer has an extinction ratio of -18 dB at 1530 nm and between -13 and -19 dB over the whole 1460-1580 nm range.
Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2012. Vol. 8431, 84311-84311 p.
, Proceedings of SPIE, ISSN 0277-786X ; 8431
Integrated Mach-Zehnder interferometer, SOI rib waveguide, single-mode criteria, apodized surfacegrating coupler, multimode interference coupler
Other Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-95291DOI: 10.1117/12.921815ISI: 000305452700040ScopusID: 2-s2.0-84861984786ISBN: 978-0-8194-9123-7OAI: oai:DiVA.org:kth-95291DiVA: diva2:527464
SPIE Photonics Europe, Brussels, April 16-19, 2012
FunderSwedish Research Council, B0460801
QC 201206122012-06-122012-05-212013-09-16Bibliographically approved