title: Design of broadband subwavelength grating couplers with low back reflection.
abstract: We present a methodology to design broadband grating couplers using one-dimensional subwavelength gratings. Using the presented method, we design subwavelength grating couplers (SWGCs) with 1-dB bandwidths ranging from 50 to 90 nm. Our designed SWGCs have competitive coupling efficiency, as high as -3.8  dB for the fundamental TE mode, and state-of-the-art back reflections, as low as -23  dB.
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Shi
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.forename: Zeqin
authors.initials: Z
authors.lastname: Lu
authors.forename: Michael
authors.initials: M
authors.lastname: Caverley
authors.forename: Richard
authors.initials: R
authors.lastname: Bojko
authors.forename: Lukas
authors.initials: L
authors.lastname: Chrostowski
authors.forename: Nicolas A F
authors.initials: NA
authors.lastname: Jaeger