Modal Spectroscopy of Optoexcited Vibrations of a Micron-Scale On-Chip Resonator at Greater than 1 GHz Frequency

We analyze experimentally and theoretically >1 GHz optoexcited mechanical vibration in an on-chip micron-scaled sphere. Different eigen-mechanical modes are excited upon demand by the centrifugal radiation pressure of the optical whispering-gallery-mode, enabling an optomechanical modal spectroscopy investigation of many vibrational modes. Spectral analysis of the light emitted from the device enables deduction of its natural vibrational modes in analogy with spectroscopy of a molecule's vibrational levels, and its eccentricity perturbation is shown to induce spectral splitting

Tweezers controlled resonator

We experimentally demonstrate trapping a microdroplet with an optical tweezer and then enabling it as a microresonator by bringing it close to a tapered fiber coupler. Our tweezers facilitated the tuning of the coupling from the under-coupled to the critically coupled regime with an optical Q of 12 million and microresonator size at the 85 mirons scale.Comment: 5 pages, 4 figure

Dynamical thermal behavior and thermal self-stability of microcavities

As stability and continuous operation are important for almost any use of a microcavity, we demonstrate here experimentally and theoretically a self-stable equilibrium solution for a pump-microcavity system. In this stable equilibrium, intensity- and wavelength-perturbations cause a small thermal resonant-drift that is enough to compensate for the perturbation (noises); consequently the cavity stays warm and loaded as perturbations are self compensated. We also compare here, our theoretical prediction for the thermal line broadening (and for the wavelength hysteretic response) to experimental results

Direct imaging of tunneling from a potential well

We experimentally map the wavefunction in the vicinity of a radial potential well. We photograph light intensity near the tunneling region as well as measure the spiraling phase structure via interference with a reference wave. This spiraling phase structure is required for conservation of angular momentum. The experimental image reveals the non-intuitive emission of light from a region in space that is empty of material and relatively far from the device

Chaotic Quivering of Micron-Scaled On-Chip Resonators Excited by Centrifugal Optical Pressure

Opto-mechanical chaotic oscillation of an on-chip resonator is excited by the radiation-pressure nonlinearity. Continuous optical input, with no external feedback or modulation, excites chaotic vibrations in very different geometries of the cavity (both tori and spheres) and shows that opto-mechanical chaotic oscillations are an intrinsic property of optical microcavities. Measured phenomena include period doubling, a spectral continuum, aperiodic oscillations, and complex trajectories. The rate of exponential divergence from a perturbed initial condition (Lyapunov exponent) is calculated. Continuous improvements in cavities mean that such chaotic oscillations can be expected in the future with many other platforms, geometries, and frequency spans

Opto-Mechanical Chaotic Behaviour of Micron-Scaled On-Chip Resonators

Opto-mechanical vibration of an on-chip oscillator is experimentally excited by radiation-pressure nonlinearity to a regime where oscillation is chaotic. Period-doubling and broad power spectra are measured in spherical and toroidal-resonators

Pattern formation in a ring cavity with temporally incoherent feedback

We present a theoretical and experimental study of modulation instability and pattern formation in a passive nonlinear optical cavity that is longer than the coherence length of the light circulating in it. Pattern formation in this cavity exhibits various features of a second-order phase transition, closely resembling laser action