Etched Waveguide Grating Variable 1 2 Splitter/Combiner and Waveguide Coupler

Dept. of Electron. Eng., Chinese Univ. of Hong Kong, Shatin
IEEE Photonics Technology Letters (Impact Factor: 2.18). 04/2009; DOI: 10.1109/LPT.2008.2010559
Source: IEEE Xplore

ABSTRACT We propose and test a silicon waveguide grating which serves dual functions: as a 1 times 2 variable integrated beam splitter/combiner and as an out-of plane diffractive element for coupling light between a single-mode optical fiber and a 500-nm-wide silicon-on-insulator waveguide. An integrated Mach-Zehnder interferometer made with this novel functional element had over 20-dB extinction ratio. The splitting ratio can be tuned by changing the launch position of the optical fiber. The grating coupler had over 36% coupling efficiency and a 1-dB spectral bandwidth of 37 nm.

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