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arXiv · 1808.07630

Inverse design and demonstration of broadband grating couplers

Neil V. Sapra·Dries Vercruysse·Logan Su·Ki Youl Yang·Jinhie Skarda·Alexander Y. Piggott·Jelena Vučković
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Abstract

We present a gradient-based optimization strategy to design broadband grating couplers. Using this method, we are able to reach, and often surpass, a user-specified target bandwidth during optimization. The designs produced for 220 nm silicon-on-insulator are capable of achieving 3 dB bandwidths exceeding 100 nm while maintaining central coupling efficiencies ranging from -3.0 dB to -5.4 dB, depending on partial-etch fraction. We fabricate a subset of these structures and experimentally demonstrate gratings with 3 dB bandwidths exceeding 120 nm. This inverse design approach provides a flexible design paradigm, allowing for the creation of broadband grating couplers without requiring constraints on grating geometry.

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Neil V. Sapra, Dries Vercruysse, Logan Su, Ki Youl Yang, Jinhie Skarda, Alexander Y. Piggott, Jelena Vučković. 2018-08-23. Inverse design and demonstration of broadband grating couplers. https://arxiv.org/abs/1808.07630

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