消除消偏光纤陀螺克尔效应的一种方法

Method of eliminating Kerr effect for depolarized fibre optic gyroscope

研究了非线性克尔效应对光纤陀螺噪声的贡献,得到了可以通过采用宽谱光源和调制光路中的光功率来减小甚至消除克尔效应引起的非互易相位差的结果。采用调制光功率的方法消除克尔效应。为了避免因调制光功率降低探测器信噪比,通过分析探测器的噪声原理得到了保证足够信噪比的最小功率输入。设计了光纤放大器光源来实现这种光功率的调制。分别分析了泵浦光功率和泵浦方式对光源的影响,进一步协调了光纤放大器光源的输出功率和放大增益,首次证明了光纤放大器光源的优越性。在实验中,采用了光纤放大器光源的光纤陀螺的随机游走系数被减小到了原来的0.8。

The contribution of Kerr effect to noise of fiber optic gyroscope is studied,and it is shown that the nonreciprocal phase-difference,due to Kerr effect,can be reduced or even eliminated by adopting wide-spectrum optical source and modulating the light power in the optical path.Kerr effect is eliminated by the method of modulating light power.The noise principle of the detector is studied to obtain the least light power with enough signal noise ratio.The fiber amplifier source is designed to modulate the light power.The influences of pump power and manner on the source are analyzed to harmonize the output power and gain of the source.The experiment results show that,compared to normal light source,the random walk coefficient of gyroscope is reduced by 80% by using the one with fiber amplifier.