光学频率梳啁啾干涉实现绝对距离测量

本文提出一种基于光学频率梳的啁啾脉冲干涉绝对距离测量的方法.通过一对衍射光栅啁啾参考脉冲,分析参考脉冲和测量脉冲的干涉光谱,得到脉冲的中心频率偏移量,从而解算出被测距离.文中详细分析了脉冲啁啾原理和啁啾脉冲干涉测距原理,以及影响测距范围的因素并给出仿真.搭建了改进的Michelson干涉结构,实验得出测距范围受啁啾参数的影响,并与理论分析吻合;在地下长导轨上,进行大范围测距实验.实验结果表明当,在65 m范围内,测量结果与参考测距仪相比,测距精度为33μm,相对精度达到5.1×10~(-7).此外,根据理论分析,通过实验优化了实验装置的测量不确定度.

Absolute distance ranging by means of chirped pulse interferometry

Large-range and high-accuracy absolute distance measurement plays an important role in many practical applications, such as industrial production, aerospace and scientific research, etc. In this paper, a method is proposed for absolute distance measurement by chirped pulse interferometry based on the femtosecond optical frequency comb. The interference spectra obtained in experiments are analyzed by means of the principle of the dispersive interference, and the distance can be determined by the shift of the widest fringe in the interference spectra. An absolute distance measurement system can be set up based on the modified Michelson interferometer with a pair of gratings to chirp the reference pulses in the reference arm. Experimental results are in agreement well within 33 μm in a range up to 65 m, i.e. a relative precision of 5.1×10^-7. In addition, the optimization of the measurement uncertainty is theoretically and experimentally performed.