Opto-Acoustic Oscillator Using Silicon Mems Optical Modulator

We show operation of a silicon MEMS based narrow-band optical modulator with large modulation depth by improving the electro-mechanical transducer. We demonstrate an application of the narrowband optical modulator as both the filter and optical modulator in an opto-electronic oscillator loop to obtain a 236.22 MHz Opto-Acoustic Oscillator (OAO) with phase noise of -68 dBc/Hz at 1 kHz offset

Simultaneous radiation pressure induced heating and cooling of an opto-mechanical resonator

Cavity opto-mechanics enabled radiation-pressure coupling between optical and mechanical modes of a micro-mechanical resonator gives rise to dynamical backaction, enabling amplification and cooling of mechanical motion. Due to a combination of large mechanical oscillations and necessary saturation of amplification, the noise floor of the opto-mechanical resonator increases, rendering it ineffective at transducing small signals, and thereby cooling another mechanical resonance of the system. Here we show amplification of one mechanical resonance in a micro-mechanical ring resonator while simultaneously cooling another mechanical resonance by exploiting two closely spaced optical whispering gallery mode cavity resonances

Z-Axis Optomechanical Accelerometer

We demonstrate a z-axis accelerometer which uses waveguided light to sense proof mass displacement. The accelerometer consists of two stacked rings (one fixed and one suspended above it) forming an optical ring resonator. As the upper ring moves due to z-axis acceleration, the effective refractive index changes, changing the optical path length and therefore the resonant frequency of the optical mode. The optical transmission changes with acceleration when the laser is biased on the side of the optical resonance. This silicon nitride "Cavity-enhanced OptoMechanical Accelerometer" (COMA) has a sensitivity of 22 percent-per-g optical modulation for our highest optical quality factor (Q_o) devicesComment: Published in Proceedings of the 25th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2012), Paris, France, January 29 - Feb 2, 2012, pp. 615-61