Noise suppression method of light source in a giant fiber optic gyroscope
A giant high precision fiber optic gyroscope(G-FOG)is a new tool for precise measurement of universal time(UT1).The significant light intensity noise,which is caused by broadband amplified spontaneous emission(ASE)light sources limits the further improvement of fiber optic gyroscope(FOG)performance.To solve the problem,a noise suppression method of light source in a giant fiber optic gyroscope is proposed.Based on the feedback device of an acousto-optic modulator(AOM),a light intensity locking experiment device of a broadband ASE light source is designed and constructed.Through the optimization of proportional integral(PI)parameters,the suppression of major noise sources is realized.The experimental results show that the relative intensity noise(RIN)of the light source can be effectively suppressed in the frequency range of 1 Hz～10 kHz.At the eigen modulation frequency of 10 kHz for a FOG with 10 km fiber coil,the RIN suppression reaches 15 dB and the angular random walk(ARW)is expected to be improved by 6 times.Meanwhile,the relative fluctuation of the output optical power of the broadband ASE light source is reduced by 80% in the mid-term(10000 s)compared with the free running case.The proposed method can improve the short-and mid-term bias stability of G-FOG,and is helpful for UT1 precision measurement based on high precision G-FOG.
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维普
