학술논문
Inverse Design and Demonstration of Broadband Grating Couplers
Document Type
Periodical
Author
Source
IEEE Journal of Selected Topics in Quantum Electronics IEEE J. Select. Topics Quantum Electron. Selected Topics in Quantum Electronics, IEEE Journal of. 25(3):1-7 Jun, 2019
Subject
Language
ISSN
1077-260X
1558-4542
1558-4542
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 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.