title: Wideband subwavelength gratings for coupling between silicon-on-insulator waveguides and optical fibers.
abstract: We propose and experimentally demonstrate a novel subwavelength grating coupler on silicon-on-insulator, for coupling to optical fibers with a wide optical bandwidth. Theoretical analysis and design optimization of the coupler are described. About 73 nm 1 dB bandwidth was experimentally demonstrated with -5.6  dB coupling efficiency. Better than -3.4  dB efficiency with 86 nm 1 dB bandwidth is predicted for these structures with optimized buried oxide thickness.
authors.affiliation: Department of Electronic Engineering, The Chinese University of Hong Kong, NT, Hong Kong, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
authors.forename: Zhenzhou
authors.initials: Z
authors.lastname: Cheng
authors.forename: Christy K Y
authors.initials: CK
authors.lastname: Fung
authors.forename: Hon K
authors.initials: HK
authors.lastname: Tsang