title: Broadband opto-electro-mechanical effective refractive index tuning on a chip.
abstract: Photonic integrated circuits have enabled progressively active functionality in compact devices with the potential for large-scale integration. To date the lowest loss photonic circuits are achieved with silica or silicon nitride-based platforms. However, these materials generally lack reconfigurability. In this work we present a platform for achieving active functionality in any dielectric waveguide via large-scale opto-electro-mechanical tuning of the effective refractive index (Δneff≈0.01-0.1) and phase (Δϕ>2π). A suspended microbridge weakly interacts with the evanescent field of a low-mode confinement waveguide to tune the effective refractive index and phase with minimal loss. Metal-coated bridges enable electrostatic actuation to displace the microbridge to dynamically tune nEFF. In a second implementation we place a non-metallized dielectric microbridge in a gradient electric field to achieve actuation and tuning. Both approaches are broadband, universally applicable to any waveguide, and pave the way for adding active functionality to many passive optical materials.
authors.forename: Marcel W
authors.initials: MW
authors.lastname: Pruessner
authors.forename: Doweon
authors.initials: D
authors.lastname: Park
authors.forename: Todd H
authors.initials: TH
authors.lastname: Stievater
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Kozak
authors.forename: William S
authors.initials: WS
authors.lastname: Rabinovich