title: Focusing-curved subwavelength grating couplers for ultra-broadband silicon photonics optical interfaces.
abstract: We report on the design and characterization of focusing-curved subwavelength grating couplers for ultra-broadband silicon photonics optical interfaces. With implementation of waveguide dispersion engineered subwavelength structures, an ultra-wide 1-dB bandwidth of over 100 nm (largest reported to date) near 1550 nm is experimentally achieved for transverse-electric polarized light. By tapering the subwavelength structures, back reflection is effectively suppressed and grating coupling efficiency is increased to -4.7 dB. A compact device footprint of 40 µm × 20 µm is realized by curving the gratings in a focusing scheme.
authors.forename: Qiuhang
authors.initials: Q
authors.lastname: Zhong
authors.forename: Venkat
authors.initials: V
authors.lastname: Veerasubramanian
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Shi
authors.forename: David
authors.initials: D
authors.lastname: Patel
authors.forename: Samir
authors.initials: S
authors.lastname: Ghosh
authors.forename: Alireza
authors.initials: A
authors.lastname: Samani
authors.forename: Lukas
authors.initials: L
authors.lastname: Chrostowski
authors.forename: Richard
authors.initials: R
authors.lastname: Bojko
authors.forename: David V
authors.initials: DV
authors.lastname: Plant