Zero-bias-suppressed angular velocity sensing via a dual-frequency optoelectronic oscillator

This paper proposes and experimentally validates what we believe to be a novel angular velocity sensing scheme based on a dual-frequency optoelectronic oscillator (OEO), which enhances sensitivity while significantly improving zero-bias stability, thereby strengthening environmental immunity. The system generates dual microwave signals through a single OEO structure and implements differential sensing within a shared Sagnac loop. The Sagnac effect induces a phase difference that creates opposite frequency shifts of the two microwave signals, while the nearly identical optical paths of the dual oscillation modes ensure identical frequency perturbations from environmental disturbances. By detecting the beat frequency signal of these signals, the system achieves a twofold enhancement in angular velocity sensitivity and over 83-fold improvement in zero-bias stability compared to conventional single-channel OEO configurations. This dual-frequency differential methodology effectively suppresses common-mode environmental perturbations while amplifying Sagnac-induced frequency shifts, demonstrating significant potential for high-precision inertial sensing applications.