title: A fully integrated high-Q Whispering-Gallery Wedge Resonator.
abstract: Microresonator devices which possess ultra-high quality factors are essential for fundamental investigations and applications. Microsphere and microtoroid resonators support remarkably high Q's at optical frequencies, while planarity constrains preclude their integration into functional lightwave circuits. Conventional semiconductor processing can also be used to realize ultra-high-Q's with planar wedge-resonators. Still, their full integration with side-coupled dielectric waveguides remains an issue. Here we show the full monolithic integration of a wedge-resonator/waveguide vertically-coupled system on a silicon chip. In this approach the cavity and the waveguide lay in different planes. This permits to realize the shallow-angle wedge while the waveguide remains intact, allowing therefore to engineer a coupling of arbitrary strength between these two. The precise size-control and the robustness against post-processing operation due to its monolithic integration makes this system a prominent platform for industrial-scale integration of ultra-high-Q devices into planar lightwave chips.
authors.affiliation: Nanoscience Laboratory, Dept Physics, University of Trento, Via Sommarive 14, I-38123 Trento, Italy.
authors.forename: Fernando
authors.initials: F
authors.lastname: Ramiro-Manzano
authors.forename: Nikola
authors.initials: N
authors.lastname: Prtljaga
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Pavesi
authors.forename: Georg
authors.initials: G
authors.lastname: Pucker
authors.forename: Mher
authors.initials: M
authors.lastname: Ghulinyan
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008904:Miniaturization; D055096:Optical Devices; D012031:Refractometry / Q000295:instrumentation*; D018511:Systems Integration; D014159:Transducers