Design of ASE source for high precision FOG

Abstract

Based on the application field of high precision Fiber optic gyroscope (FOG), high requirements are put forward for the accuracy of FOG, the stability of scale factor and the nonlinearity of scale factor. The performance of light source is closely related to the performance of these gyroscopes. Therefore, the requirements of high power, high stability, high spectral symmetry and low coherence are put forward for light source. According to the characteristics of high precision FOG, an ASE source is proposed. In the light path aspect, the physical model of ASE light source, the influence of Erbium-doped fiber length, optical path structure scheme, pump wavelength and pump power on the average wavelength of the light source are analyzed. The optical path structure and the length and pump power range of Erbium-doped fiber are determined. Through the analysis of spectral coherence, the Gauss spectrum with no sub-peak of the coherence function is selected as the filtering scheme through orthogonality. Optimize the parameters of light source by experiment and filter simulation. In the aspect of power control, improving power stability by power feedback with controlling the temperature characteristics of the feedback loop device. The ASE light source designed above can provide power output of more than 20 mW. Within operation temperature of high precision FOG, the change of wavelength stability is less than 5 ppm and the change of power output is less than 1%. It is an ideal light source for high precision FOG.