A silicon nitride optomechanical oscillator with zero flicker noise

We present an integrated chip-scale Radiation-Pressure driven Opto-Mechanical Oscillator (RP-OMO) in silicon nitride with excellent close-to-carrier phase noise. We illustrate a process to micro-fabricate optomechanical resonators, waveguides and grating couplers in silicon nitride and demonstrate an RP-OMO operating at 41.95MHz, with phase noise of -85dBc/Hz at 1kHz offset. The phase noise does not show 1/f
³
or other higher order slopes all the way down to 10Hz offset from carrier. Using a lower optical quality factor resonance, we demonstrate improvement of 6dB in phase noise.