Underwater Acoustic Signal Detection and Down-Conversion Using Optomechanical Resonance and Oscillation

We have studied the performance of optomechanical resonators and oscillators as high sensitivity underwater acousto-optical receivers and signal processors. In the absence of optomechanical oscillation, optomechanical resonator functions as a very sensitive acousto-optical transducer with low-power consumption. In the presence of optomechanical oscillation we show that optomechanical oscillator can simultaneously function as an acousto-optical transducer and frequency down-converter that extracts the IF or baseband signal from an ultrasonic carrier without the need for RF local oscillator and mixer.