title: Two-dimensional grating coupler with a low polarization dependent loss of 0.25  dB covering the C-band.
abstract: We design and demonstrate a two-dimensional grating coupler (2D GC) with a low polarization dependent loss (PDL) based on the silicon-on-insulator (SOI) platform. Using a grating cell consisting of five cylinders and carefully optimizing the distances between the cylinders, a maximum PDL of 0.25 dB covering the C-band is realized, which is 1.25 dB better than a conventional 2D GC with a single cylinder etching pattern fabricated on the same SOI wafer.
authors.forename: Jinghui
authors.initials: J
authors.lastname: Zou
authors.forename: Yu
authors.initials: Y
authors.lastname: Yu
authors.forename: Xinliang
authors.initials: X
authors.lastname: Zhang