title: High-Q/V Monolithic Diamond Microdisks Fabricated with Quasi-isotropic Etching.
abstract: Optical microcavities enhance light-matter interactions and are essential for many experiments in solid state quantum optics, optomechanics, and nonlinear optics. Single crystal diamond microcavities are particularly sought after for applications involving diamond quantum emitters, such as nitrogen vacancy centers, and for experiments that benefit from diamond's excellent optical and mechanical properties. Light-matter coupling rates in experiments involving microcavities typically scale with Q/V, where Q and V are the microcavity quality-factor and mode-volume, respectively. Here we demonstrate that microdisk whispering gallery mode cavities with high Q/V can be fabricated directly from bulk single crystal diamond. By using a quasi-isotropic oxygen plasma to etch along diamond crystal planes and undercut passivated diamond structures, we create monolithic diamond microdisks. Fiber taper based measurements show that these devices support TE- and TM-like optical modes with Q > 1.1 × 10(5) and V < 11(λ/n) (3) at a wavelength of 1.5 μm.
authors.affiliation: †Department of Physics and Astronomy and Institute for Quantum Science and Technology, University of Calgary, Calgary, AB T2N 1N4, Canada.|‡National Institute for Nanotechnology, 11421 Saskatchewan Drive Northwest, Edmonton, AB T6G 2M9, Canada.
authors.forename: Behzad
authors.initials: B
authors.lastname: Khanaliloo
authors.affiliation: †Department of Physics and Astronomy and Institute for Quantum Science and Technology, University of Calgary, Calgary, AB T2N 1N4, Canada.|‡National Institute for Nanotechnology, 11421 Saskatchewan Drive Northwest, Edmonton, AB T6G 2M9, Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: Mitchell
authors.affiliation: ‡National Institute for Nanotechnology, 11421 Saskatchewan Drive Northwest, Edmonton, AB T6G 2M9, Canada.|§nanoFAB Facility, University of Alberta, Edmonton, AB T6G 2R3, Canada.
authors.forename: Aaron C
authors.initials: AC
authors.lastname: Hryciw
authors.affiliation: †Department of Physics and Astronomy and Institute for Quantum Science and Technology, University of Calgary, Calgary, AB T2N 1N4, Canada.|‡National Institute for Nanotechnology, 11421 Saskatchewan Drive Northwest, Edmonton, AB T6G 2M9, Canada.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Barclay
keywords: Diamond; microcavity; microdisk; nanofabrication; nanophotonics