We compare the resonant fiber-optic gyroscope (RFOG) with the interferometric fiber-optic gyroscope (IFOG). The fiber ring length of the RFOG is only tens of meters or even several meters, which not only reduces the volume and weight but also decreases the noise resulting from the uneven distribution of temperature and stress in the fiber ring. However, due to the high coherence of narrow linewidth light sources, there are some additional noises like backscattered noise that are difficult to eradicate in the system. The new generation RFOG using a broad spectrum light source can reduce the coherence term in backscattered noise, further enhancing the performance of the wide spectrum RFOG. However, the direct current (DC) term of backscattered noise in the system cannot be removed, restricting the accuracy of the gyroscope. Therefore, it is of great significance for us to improve the detection accuracy of the system by reducing the DC term of backscattered noise in the broad spectrum RFOG. Our research aims to reduce the backscattered noise by optimizing the relevant parameters of the system, thus improving the gyroscope performance.

We analyze the interference of clockwise and counterclockwise light in the resonator. Theoretically, we obtain the relationship between the DC term and the wavelength in the backscattered noise. We simulate the variation trend of backscattered noise with wavelength and refractive index. We construct a broad spectrum RFOG system and measure the variation of backscattering light intensity with wavelength through experiments to verify the correctness of the theory.

The RFOG driven by a broadband source can reduce the coherence term of backscattered noise in the gyroscope system, but the DC term still limits the improvement of gyroscope performance. According to the simulation results, the backscattered intensity decreases with the increase of wavelength and increases with the increase of the refractive index. Therefore, in practical applications, it is advisable to select a light source with a large working wavelength and devices with a small refractive index of pigtail to reduce backscattered noise. The results of the backscattered noise test show a decrease in backscattered noise with increased wavelength, which is consistent with the simulation result. The angular random walk (ARW), which measures the rate of change of the gyroscope’s output with respect to time, of the RFOG driven by a broadband source decreases with the increase of wavelength, indicating the practical benefits of our research in improving gyroscope performance.

Our study has obtained significant results by optimizing the wavelength of a broadband source and its correlation with backscatter theory. We conclude that the longer the wavelength, the smaller the backscattering of the gyroscope system and its components, and the smaller the angular random walk (ARW) of the gyroscope. Compared with the 1540 nm wavelength, the ARW and backscattering intensity (BI) of the gyroscope at 1554 nm are reduced by 15% and 25% respectively. This provides crucial insights for the selection of the working wavelength of the source and the improvement of the angular random walk of the RFOG driven by a broadband source. At room temperature, the tuning range of the super luminescent diode (SLD) light source at the 1550 nm band is only about ±10 nm, so this method has limited space for improving the ARW of the gyroscope. At present, there are SLDs with a central wavelength of 1650 nm on the market, and further experiments are needed to verify the improvement of gyroscope performance after increasing the wavelength. Since other factors also affect the intensity of backscattered light in the experiment, the backscattering magnitude caused by specific devices in the system can be determined by isolation experiments in the future, so as to reduce the backscattering of the gyroscope system by reducing the backscattering of devices.