title: Design for broadband on-chip isolator using Stimulated Brillouin Scattering in dispersion-engineered chalcogenide waveguides.
abstract: We propose a scheme for on-chip isolation in chalcogenide (As₂S₃) rib waveguides, in which Stimulated Brillouin Scattering is used to induce non-reciprocal mode conversion within a multi-moded waveguide. The design exploits the idea that a chalcogenide rib buried in a silica matrix acts as waveguide for both light and sound, and can also be designed to be multi-moded for both optical and acoustic waves. The enhanced opto-acoustic coupling allows significant isolation (> 20 dB) within a chip-scale (cm-long) device (< 10 cm). We also show that the bandwidth of this device can be dramatically increased by tuning the dispersion of the waveguide to match the group velocity between optical modes: we find that 20 dB isolation can be extended over a bandwidth of 25 nm.
authors.affiliation: Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), Australia. chris.poulton@uts.edu.au
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Poulton
authors.forename: Ravi
authors.initials: R
authors.lastname: Pant
authors.forename: Adam
authors.initials: A
authors.lastname: Byrnes
authors.forename: Shanhui
authors.initials: S
authors.lastname: Fan
authors.forename: M J
authors.initials: MJ
authors.lastname: Steel
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Eggleton