title: Ideality in a fiber-taper-coupled microresonator system for application to cavity quantum electrodynamics.
abstract: The ability to achieve near lossless coupling between a waveguide and a resonator is fundamental to many quantum-optical studies as well as to practical applications of such structures. The nature of loss at the junction is described by a figure of merit called ideality. It is shown here that under appropriate conditions ideality in excess of 99.97% is possible using fiber-taper coupling to high-Q silica microspheres. To verify this level of coupling, a technique is introduced that can both measure ideality over a range of coupling strengths and provide a practical diagnostic of parasitic coupling within the fiber-taper-waveguide junction.
authors.affiliation: Thomas J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Spillane
authors.forename: T J
authors.initials: TJ
authors.lastname: Kippenberg
authors.forename: O J
authors.initials: OJ
authors.lastname: Painter
authors.forename: K J
authors.initials: KJ
authors.lastname: Vahala