耦合器传输光谱对光纤陀螺信噪比的影响

温变条件下，对光纤光源发出光波经单模光纤耦合器传输后的输出光谱进行了测试；借助测试结果，仿真计算了耦合器的透射光波和耦合光波分别进入光纤陀螺后干涉仪输出信号的信噪比随温度的变化情况.结果表明：当环境温度发生变化时，耦合器透射光波和耦合光波的功率、波长和谱宽都会发生变化，且透射光波的功率、波长和谱宽的温度稳定性远高于耦合光波的稳定性；当耦合光波作为干涉仪输入光波时，由温变引起的光纤陀螺信噪比误差约是透射光波作为输入光波时的信噪比误差的4倍.

Influence of the transmitting spectra of fiber coupler on the SNR of FOGs

The output spectra of fiber source, which transmitted through a single-mode (SM) fiber coupler, were measured by changing temperature. When the input wave of the fiber optical gyroscope (FOG) from the fiber coupler were transmitting wave and coupling wave, respectively, the temperature characteristics of signal-to-noise ratios (SNR) of FOG were simulated. The above experimental results demonstrate that the output power, mean-wavelength and spectral width of the spectra traveling through the arm of directly-transmission and that of the coupling of coupler will change when the temperature changes, and the temperature-stability of output power, mean-wavelength and spectral width of the directly-transmission arm is higher than that of the coupling arm. And the simulated results demonstrate that the errors of FOG's caused by the light wave outputting from the coupling arm of SM fiber coupler are almost 4 times of that from the directly-transmission arm.