Improvement of ARW in Broadband Source-Driven RFOG Using Reflection-Type Fiber Ring Resonator

The angle random walk (ARW) of the broadband source-driven resonant fiber-optic gyroscope (RFOG) has approached a level comparable to the shot-noise-limited sensitivity. However, for the previously proposed RFOG schemes with a transmission-type fiber ring resonator (FRR), ARW can only be improved by increasing the length of the fiber coil, which hinders the trend toward miniaturization. In this article, a novel broadband source-driven RFOG that uses a reflection-type FRR is proposed. This scheme reduces the loss of the resonator by eliminating one internal fiber coupler and reduces excessive relative intensity noise (RIN) by using the polarization separation method. We demonstrate that the shot-noise-limited ARW can be theoretically improved by nearly a factor of two compared to the previous schemes without increasing the length of the fiber coil. The experimental results show that the ARW of 0.0038°/h<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{1/2}$ </tex-math></inline-formula> is achieved with a 110 m-long and 10 cm-diameter FRR. This novel scheme effectively improves the theoretical sensitivity of RFOG driven by a broadband source while reducing their cost and complexity. It is meaningful for the engineering application of high-precision and miniaturization RFOG.