Vertical Injection and Wideband Grating Coupler Based on Asymmetric Grating Trenches

2021/10/26 by Md. Asaduzzaman, Robert J. Chapman, Asaduzzaman, Md +5
Engineering · Materials Science · #Advanced Fiber Optic Sensors #Applied Physics (physics.app-ph) #FOS: Physical sciences #Optical Coatings and Gratings #Optics (physics.optics) #Photonic and Optical Devices #Quantum Physics (quant-ph)

paper · pdf · doi:10.48550/arxiv.2110.14085

openalex publication_date 2021/10/26 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28

Abstract

A Silicon-on-insulator (SOI) perfectly vertical fibre-to-chip grating coupler is proposed and designed based on engineered subwavelength structures. The high directionality of the coupler is achieved by implementing step gratings to realize asymmetric diffraction and by applying effective index variation with auxiliary ultra-subwavelength gratings. The proposed structure is numerically analysed by using two-dimensional Finite Difference Time Domain (2D FDTD) method and achieves 76% (-1.19 dB) coupling efficiency and 39 nm 1-dB bandwidth.

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