Kerry J. Vahala

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Optical microcavities confine light to small volumes by resonant recirculation. Devices based on optical microcavities are already indispensable for a wide range of applications and studies. For example, microcavities made of active III-V semiconductor materials control laser emission spectra to enable long-distance transmission of data over optical fibres;(More)
The dynamic back-action caused by electromagnetic forces (radiation pressure) in optical and microwave cavities is of growing interest. Back-action cooling, for example, is being pursued as a means of achieving the quantum ground state of macroscopic mechanical oscillators. Work in the optical domain has revolved around millimetre- or micrometre-scale(More)
We investigate the suitability of toroidal microcavities for strong-coupling cavity quantum electrodynamics sQEDd. Numerical modeling of the optical modes demonstrate a significant reduction of the modal volume with respect to the whispering gallery modes of dielectric spheres, while retaining the high-quality factors representative of spherical cavities.(More)
We present for the first time a detailed experimental study of the oscillation frequency, linewidth, RF spectrum and the phase noise of a radiation-pressure-driven micromechanical oscillator in a microtoroid geometry. Through this study we identify the critical parameters for optimal operation of this device and derive key expressions for tailoring the(More)
Current single-molecule detection techniques require labeling the target molecule. We report a highly specific and sensitive optical sensor based on an ultrahigh quality (Q) factor (Q > 10(8)) whispering-gallery microcavity. The silica surface is functionalized to bind the target molecule; binding is detected by a resonant wavelength shift. Single-molecule(More)
Here we propose and demonstrate an all-optical wavelength-routing approach which uses a tuning mechanism based upon the optical gradient force in a specially-designed nano-optomechanical system. The resulting mechanically-compliant “spiderweb” resonantor realizes seamless wavelength routing over a range of 3000 times the intrinsic channel width, with a(More)
We present the observation of critical coupling in a high-Q fused-silica microsphere whispering-gallery mode resonator coupled to a fiber taper. Extremely efficient and controlled power transfer to high-Q 107 resonators has been demonstrated. Off-resonance scattering loss was measured to be less than 0.3%. On-resonance extinction in transmitted optical(More)
Periodicity in materials yields interesting and useful phenomena. Applied to the propagation of light, periodicity gives rise to photonic crystals, which can be precisely engineered for such applications as guiding and dispersing optical beams, tightly confining and trapping light resonantly, and enhancing nonlinear optical interactions. Photonic crystals(More)
We analyze experimentally and theoretically mechanical oscillation within an optical cavity stimulated by the pressure of circulating optical radiation. The resulting radio frequency cavity vibrations (phonon mode) cause modulation of the incident, continuous-wave (cw) input pump beam. Furthermore, with increasing cw pump power, an evolution from sinusoidal(More)
The coupling of mechanical and optical degrees of freedom via radiation pressure has been a subject of early research in the context of gravitational wave detection. Recent experimental advances have allowed studying for the first time the modifications of mechanical dynamics provided by radiation pressure. This paper reviews the consequences of back-action(More)