Study On The Effect Of Broad-band Source's Spectrum Characteristic To The Fiber Optic Gyroscope

Because of the advantage of simple structure, small volume, high sensitivity and wide dynamic range, Fiber Optic Gyroscope (FOG) has been widely used in commercial and military field. Broad-band light source is the key device of FOG, the performance of the light source determines the performance of the FOG This paper study on the effect of Super-fluorescent Fiber Source (SFS) to the FOG, then derive some usable conclusions.At first, we programmed some programming in the environment of MATLAB, simulated spectrums with different characteristics which are basic characteristics (width, shape), ripple characteristics and dissymmetry characteristics. Based on the spectrum derived form the programming, self-coherent function had been worked out by discretization method. Then we analyzed the effect of spectrums' characteristics on self-coherent function.Based on the spectrum simulation and calculation of self-coherent function, modeling analyzed some noises about FOG and spectrums' characteristics, and gained the quantitative relation between variety noises and spectrums' characteristics. Through the model, the paper calculated the noises of FOG resulted by different spectrums' characteristics.Using the self-coherent function data, we worked out the curves which describe the relationship between interference light intensity and angular velocity. By fitting the curve, we derived the Scale Factor (SF) of the FOG, and then derived the relationship between spectrum's characteristics (width, dissymmetry) and Scale Factor. According to the method introduced above, we analyzed how Erbium-doped Super-fluorescent Fiber Source (ED-SFS) changing with drive power affects on Scale Factor.Based on the spectrum data of ED-SFS measured by spectrum apparatus actually, we calculated the noises and gained the conclusion of certain significance. The temperature experiment was done using Fiber Source manufactured by our staff room, and the results of spectrum show that the Scale Factor stability of Fiber Source prototype is 8.65 ppm/℃, satisfied the requirement of medium precision.At last, aiming at the disadvantage of spectrum's flattening method, we bring forward a new method of spectrum filtering which can conquer the disadvantage, for reference.