Suppression of RIN in broadband source-driven RFOG using a light intensity fluctuation offset technique

Abstract

Optical noise in resonant fiber-optic gyro (RFOG), such as coherence-related noise, has been suppressed using a broadband source. Consequently, the relative intensity noise (RIN) of optical source has become the primary source of interference in RFOG. There have been some methods to suppress the RIN, but they are all passive and still affected by the fluctuation of light source. In this paper, we propose a light intensity fluctuation offset technique to actively suppress the RIN, thereby improving the performance of angle random walk (ARW). This technique can completely offset light intensity fluctuations in theoretically. In experiment, the ARW is 0.0031 $°/h^{1/2}$ which represents a 18.4% improvement compared to that of the traditional passive scheme in a 114-m-long fiber ring resonator (FRR) with an internal diameter of 6 cm. This work effectively reduces short-term fluctuation and is significant for RFOG applications.