Noise-Enhanced Sensing of Light and Magnetic Force Based on a Nonlinear Silicon Microresonator

Microresonators with mechanical nonlinearity are applied to sensing based on the noise-enhanced stochastic transition of the vibration amplitude in bistable mechanical systems at resonance. Noise-enhanced stochastic transitions can amplify a signal in a nonlinear system. It was found that 100-nm-thick single-crystalline silicon resonators exhibit mechanical nonlinearity with both negative and positive nonlinear coefficients, depending on the vibration frequency at large vibration amplitudes. It was demonstrated that the noise-enhanced stochastic transition can be synchronized with periodic optical stimuli with in-phase or anti-phase, depending on the operation frequency. In addition, the detection of a magnetic field was demonstrated using a resonator with a micromagnet on the basis of noise-enhanced transitions. (C) 2008 The Japan Society of Applied Physics