载波调制型大气光学湍流光纤测量系统的实验研究

Experimental Study on Carrier Modulated Fiber Optic Atmospheric Optical Turbulence Measurement System

介绍了利用载波调制型光纤Mach-Zehnder干涉仪测量大气光学湍流折射率起伏的原理,给出了载波调制信号的解调方法。实验研究表明,该系统测量大气折射率起伏方差的噪声水平为2.5×10^(-16)。在真实的大气环境下,通过与传统温度脉动仪的对比测试分析表明,两者的探测结果无论在量级上还是在变化趋势上都有很好的一致性,这标志着大气湍流的光纤测量技术已初步迈入实用阶段。

Principle of measuring refractive index fluctuation in atmospheric optical turbulence by the usage of a carrier modulated fiber optical Mach-Zehnder interferometer is introduced, as well as the signal processing procedure. Experiments show that the noise level of the system Cn^2 variance is about 2.5 × 10^-16. Comparison of the results with that of the traditional micro-thermal anemometer in the real atmosphere shows good agreement in the values and trends, which indicates that the fiber optic turbulence sensing technique is alreadyapplicable.