Sensitivity Enhancement Method for Dual-Polarization Interferometric Fiber-Optic Angular Accelerometer

High-performance angular accelerometers have important applications in the fields of inertial navigation, dynamic control, and rotational seismology. Here, we propose a type of angular accelerometer based on a dual-polarization fiber-optic Sagnac interferometer, which does not rely on any mechanical structure and has strong environmental adaptability. Three methods are adopted to improve the sensitivity, namely, the dual-light source structure, noise suppression, and increased sensing area of the fiber coil. The experimental results show that these methods effectively improve the performance of the proposed angular accelerometer. Finally, the proposed fiber-optic angular accelerometer based on dual-light source and noise suppression structure achieves a measurement sensitivity of $8.9\times 10^{-{9}}$ rad/ $\text{s}^{{2}}/\sqrt {\text {Hz}}$ with a sensing area of 240 $\text{m}^{{2}}$ . The frequency response is flattened in the bandwidth range of 0.002–125 Hz. This research is expected to overcome the limitations of the existing angular acceleration measurement methods, which provides both a theoretical and experimental basis for the development of novel high-performance angular accelerometers.