title: Single-etch subwavelength engineered fiber-chip grating couplers for 1.3 µm datacom wavelength band.
abstract: We report, for the first time, on the design and experimental demonstration of fiber-chip surface grating couplers based on subwavelength grating engineered nanostructure operating in the low fiber chromatic dispersion window (around 1.3 μm wavelengths), which is of great interest for short-reach data communication applications. Our coupler designs meet the minimum feature size requirements of large-volume deep-ultraviolet stepper lithography processes. The fiber-chip couplers are implemented in a standard 220-nm-thick silicon-on-insulator (SOI) platform and are fabricated by using a single etch process. Several types of couplers are presented, specifically the uniform, the apodized, and the focusing designs. The measured peak coupling efficiency is -2.5 dB (56%) near the central wavelength of 1.3 μm. In addition, by utilizing the technique of the backside substrate metallization underneath the grating couplers, the coupling efficiency of up to -0.5 dB (89%) is predicted by Finite Difference Time Domain (FDTD) calculations.
authors.forename: Daniel
authors.initials: D
authors.lastname: Benedikovic
authors.forename: Carlos
authors.initials: C
authors.lastname: Alonso-Ramos
authors.forename: Pavel
authors.initials: P
authors.lastname: Cheben
authors.forename: Jens H
authors.initials: JH
authors.lastname: Schmid
authors.forename: Shurui
authors.initials: S
authors.lastname: Wang
authors.forename: Robert
authors.initials: R
authors.lastname: Halir
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ortega-Moñux
authors.forename: Dan-Xia
authors.initials: DX
authors.lastname: Xu
authors.forename: Laurent
authors.initials: L
authors.lastname: Vivien
authors.forename: Jean
authors.initials: J
authors.lastname: Lapointe
authors.forename: Siegfried
authors.initials: S
authors.lastname: Janz
authors.forename: Milan
authors.initials: M
authors.lastname: Dado