This disclosure is related to devices, systems, and techniques for determining an acceleration. For example, an accelerometer system includes a resonator and a light-emitting device configured to generate, based on an error signal, an optical signal. Additionally, the accelerometer includes a modulator configured to receive the optical signal, generate a modulated optical signal responsive to receiving the optical signal, and output the modulated optical signal to the resonator. A photoreceiver receives a passed optical signal from the resonator, where the passed optical signal indicates a resonance frequency of the resonator. Additionally, the photoreceiver receives a reflected optical signal from the resonator. The photoreceiver generates one or more electrical signals based on the passed optical signal and the reflected optical signal. Processing circuitry generates the error signal and determines the acceleration based on the one or more electrical signals.