Fig. 5. Application of modulators to optomechanical sensing system.

a A picture of an optomechanical accelerometer. Four optical ring resonators are accessible via packaging, with two being released and sensitive to acceleration. The chip was produced with a similar layer stack to Fig. 1a (however, no piezoelectric was deposited). b An optical microscope image of the SiO₂ serpentine spring structure that allows the ring resonator to be sensitive to acceleration. c A diagram explaining device operation. As the proof mass displaces, the ring resonator is perturbed, shifting the optical resonance frequency. d The experiment used to characterize the optomechanical accelerometer. e Using P_RF = 0.25 W of RF power, a PDH error signal can be generated using the modulators. f The transfer function and noise equivalent acceleration (NEA) is measured. The fundamental resonance of the released mechanical structure is near 1.8 kHz.