An apodized SOI waveguide-to-fiber surface grating coupler for single lithography silicon photonics
2011 (English)In: Optics Express, ISSN 1094-4087, Vol. 19, no 4, 3592-3598 p.Article in journal (Refereed) Published
We present the design, fabrication, and characterization of a grating for coupling between a single mode silica fiber and the TE mode in a silicon photonic waveguide on a silicon on insulator (SOI) substrate. The grating is etched completely through the silicon device layer, thus permitting the fabrication of through-etched surface coupled silicon nanophotonic circuits in a single lithography step. Furthermore, the grating is apodized to match the diffracted wave to the mode profile of the fiber. We experimentally demonstrate a coupling efficiency of 35% with a 1 dB bandwidth of 47 nm at 1536 nm on a standard SOI substrate. Furthermore, we show by simulation that with an optimized buried oxide thickness, a coupling efficiency of 72% and a 1 dB bandwidth of 38 nm at 1550 nm is achievable. This is, to our knowledge, the highest simulated coupling efficiency for single-etch TE-mode grating couplers. In particular, simulations show that apodizing a conventional periodic through-etched grating decreases the back-reflection into the waveguide from 21% to 0.1%.
Place, publisher, year, edition, pages
2011. Vol. 19, no 4, 3592-3598 p.
1550 nm, Apodizing, Buried oxide thickness, Coupling efficiency, Diffracted waves, Etched gratings, Etched surface, Fiber surface, Grating couplers, Mode profiles, Nanophotonic circuits, Silica fibers, Silicon devices, Silicon photonics, Silicon-on-insulator substrates, Single mode, SOI substrates, SOI waveguides, TE mode, Coupled circuits, Lithography, Nanophotonics, Photonic devices, Silica
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-32605DOI: 10.1364/OE.19.003592ISI: 000288860000078ScopusID: 2-s2.0-79951642749OAI: oai:DiVA.org:kth-32605DiVA: diva2:411800
QC 201104192011-04-192011-04-182013-03-25Bibliographically approved