High-efficiency focusing waveguide grating coupler withparallelogramic groove profiles |
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Authors: | Laao T. Sheard S. Ming Li Hanguo Zhu Prewett P. |
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Affiliation: | Dept. of Eng. Sci., Oxford Univ.; |
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Abstract: | A high-efficiency focusing waveguide grating coupler (FWGC) using parallelogramic group profiles is proposed, designed and fabricated. A new waveguide grating structure has been employed which consists of bilayered grating with one grating etched into the guiding layer and the other into a high-index cladding layer. Computer simulation shows that both high directionality and large radiation decay factor are obtainable with this structure. Fabrication of this FWGC by electron beam lithography is described. A coupling efficiency of 86% and focusing spot size full-width at half maximum (FWHM) of around 10 μm have been achieved |
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