Title :
Elimination of multimode effects in a silicon-on-insulator etched diffraction grating demultiplexer with bi-level taper structure
Author :
Dai, Daoxin ; He, Jian-Jun ; He, Sailing
Author_Institution :
Centre for Opt. & Electromagn. Res., Zhejiang Univ., Hangzhou, China
Abstract :
Multimode effects in the free propagation region (FPR) of an etched diffraction grating (EDG) demultiplexer based on silicon-on-insulator are analyzed. The insertion loss and the crosstalk increase due to these undesired multimode effects. A bi-level taper structure between the FPR and the input/output waveguides is proposed. It is shown that such a taper structure can reduce the multimode effects to an almost negligible level. At the same time, the 3-dB passband width is enlarged by increasing the rib width. No additional fabrication process is needed for an EDG with such a design.
Keywords :
demultiplexing equipment; diffraction gratings; etching; optical communication equipment; optical crosstalk; optical losses; optical planar waveguides; rib waveguides; silicon-on-insulator; bilevel taper; crosstalk; free propagation region; insertion loss; multimode effect elimination; silicon-on-insulator etched diffraction grating demultiplexer; Arrayed waveguide gratings; Diffraction gratings; Electromagnetic waveguides; Etching; Optical crosstalk; Optical refraction; Optical variables control; Optical waveguides; Programmable control; Silicon on insulator technology; Air slot; crosstalk; etched diffraction grating (EDG); insertion loss; multimode effect; silicon-on-insulator (SOI); taper;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/JSTQE.2005.846543
