Inverse design of a Si-based high-performance vertical-emitting meta-grating coupler on a220 nm silicon-on-insulator platform  

作　　者：JINHYEONG YOON JAE-YONG KIM JUNHYEONG KIM HYEONHO YOON BERKAY NESELI HYO-HOON PARK HAMZA KURT 

机构地区：[1]School of Electrical Engineering,Korea Advanced Institute of Science and Technology(KAIST),Daejeon,Republic of Korea

出　　处：《Photonics Research》2023年第6期897-905,共9页光子学研究（英文版）

基　　金：National Research Foundation of Korea(NRF-2022R1A2C1009773);Ministry of Education(BK Four Program);Ministry of Science and ICT,Republic of Korea(N11220016)。

摘　　要：Efficient extraction of light from a high refractive index silicon waveguide out of a chip is difficult to achieve.An inverse design approach was employed using the particle swarm optimization method to attain a vertical emitting meta-grating coupler with high coupling efficiency in a 220-nm-thick silicon-on-insulator platform.By carefully selecting the figure of merit and appropriately defining parameter space,unique L-shape and U-shape grating elements that boosted the out-of-plane radiation of light were obtained.In addition,a 65.7%(-1.82 dB)outcoupling efficiency and a 60.2%(-2.2 dB)fiber-to-chip vertical coupling efficiency with an 88 nm 3 dB bandwidth were demonstrated by numerical simulation.Considering fabrication constraints,the optimized complex meta-grating coupler was modified to correspond to two etching steps and was then fabricated with a complementary metal-oxide-semiconductor-compatible process.The modified meta-grating coupler exhibited a simulated coupling efficiency of 57.5%(-2.4 d B)with a 74 nm 3-dB bandwidth in the C-band and an experimentally measured coupling efficiency of 38%(-4.2 dB).

关 键 词：WAVEGUIDE coupling INSULATOR 

分 类 号：TN405[电子电信—微电子学与固体电子学]