Ultracompact and broadband polarization beam splitter utilizing the evanescent coupling between a hybrid plasmonic waveguide and a silicon nanowire
2013 (English)In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 38, no 16, 3005-3008 p.Article in journal (Refereed) Published
An ultracompact polarization beam splitter (PBS) is proposed based on an asymmetrical directional coupler consisting of a silicon hybrid plasmonic waveguide (HPW) and a silicon nanowire. The widths of the two coupling waveguides are chosen so that the phase-matching condition is satisfied for TE polarization only while the phase mismatch is significant for TM polarization. A sharply bent silicon HPW is connected at the thru port to play the role of polarizer by utilizing its polarization-dependent loss. With the present principle, the designed PBS has a footprint as small as only similar to 1.9 mu m x 3.7 mu m, which is the shortest PBS reported until now, even when large waveguide dimensions (e. g., the waveguide widths w(1,2) = similar to 300 nm and the gap width w(gap) = similar to 200 nm) are chosen to simplify the fabrication process. The numerical simulations show that the designed PBS has a very broad band (similar to 120 nm) with an extinction ratio >12 dB and a large fabrication tolerance to allow a waveguide width variation of similar to 30 nm.
Place, publisher, year, edition, pages
2013. Vol. 38, no 16, 3005-3008 p.
Bent Directional Coupler, Ultra-Short, Confinement, Interference, Access
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-127746DOI: 10.1364/OL.38.003005ISI: 000323204500020ScopusID: 2-s2.0-84882271038OAI: oai:DiVA.org:kth-127746DiVA: diva2:646502
QC 201309092013-09-092013-09-052013-09-09Bibliographically approved