Title :
Bilevel mode converter between a silicon nanowire waveguide and a larger waveguide
Author :
Dai, Daoxin ; He, Sailing ; Tsang, Hon-Ki
Author_Institution :
Centre for Opt. & Electromagn. Res., Zhejiang Univ., Hangzhou, China
fDate :
6/1/2006 12:00:00 AM
Abstract :
A bilevel mode converter is analyzed for providing low-loss coupling between the small fundamental mode of a silicon nanowire waveguide and the larger mode of a conventional silicon-on-insulator (SOI) rib waveguide. The bilevel converter can also be used to improve the coupling efficiency between a lensed fiber and a silicon nanowire waveguide. The mode converter consists of two tapers formed at different levels. The top taper comprises a parabolic and sine taper, which is optimized to improve the mode conversion efficiency. Numerical analyses are given by using a three-dimensional semivectorial beam propagation method. The design has good tolerance against misalignment of the two masks needed for the double etch.
Keywords :
elemental semiconductors; nanowires; optical couplers; optical design techniques; optical waveguides; rib waveguides; silicon; silicon-on-insulator; Si; bilevel mode converter; lensed fiber; low-loss coupling; mode conversion efficiency; silicon nanowire waveguide; silicon-on-insulator rib waveguide; three-dimensional semivectorial beam propagation method; Electromagnetic waveguides; Helium; Nanoscale devices; Optical refraction; Optical scattering; Optical variables control; Optical waveguides; Programmable control; Refractive index; Silicon on insulator technology; Bilevel; mode converter; nanowire waveguide; silicon; taper;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2006.874554
