title: Thermo-optomechanical oscillator for sensing applications.
abstract: We demonstrate and characterize a thermo-optomechanical oscillator based on a PMMA-coated silica microtoroid and employ it as a sensor. The observed thermo-optomechanical oscillation has a unique waveform that consists of fast and slow oscillation periods. A model based on thermal and optical dynamics of the cavity is used to describe the bi-frequency oscillation and experiments are conducted to validate the theoretical model in order to explore the origin of the two oscillatory phenomena. As opposed to previously shown hybrid toroidal microcavities, the excessive PMMA coating boosts the thermo-mechanical (expansion) effect that results in bi-frequency oscillation when coupled with the thermo-optical effect. The influences of the input power, quality factor, and wavelength detuning on oscillation frequencies are studied experimentally and verified theoretically. Finally the application of this oscillator as a sensor is explored by demonstrating the sensitivity of oscillation frequency to humidity changes.
authors.affiliation: Department of Electrical and Computer Engineering and Center for High Technology Materials (CHTM), University of New Mexico, Albuquerque, New Mexico 87106, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Deng
authors.forename: Fenfei
authors.initials: F
authors.lastname: Liu
authors.forename: Zayd C
authors.initials: ZC
authors.lastname: Leseman
authors.forename: Mani
authors.initials: M
authors.lastname: Hossein-Zadeh
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D006361:Heating / Q000295:instrumentation*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D055096:Optical Devices; D009991:Oscillometry / Q000295:instrumentation*; D014159:Transducers; D014867:Water / Q000032:analysis*
chemical_list: D014867:Water