针对使用单一频率飞秒激光纵模间拍信号测距时测量分辨力和最大非模糊距离之间的矛盾,提出了一种同时使用不同频率的微波信号对距离进行测量并逐级合成测量结果的方法。分别选取频率为100 MHz和1GHz的纵模间拍信号测量目标距离,之后调整飞秒激光器的重复频率,使1GHz的纵模间拍信号频率变化1 MHz后再次测量,借助频率变化进一步得到更大的合成波长,最后将三次测量的结果逐级合成,在扩展最大非模糊距离的同时保证了测量结果的高精度。实验结果表明,这种方法能够将最大非模糊距离扩展到150m,对目标绝对距离的测量结果不确定度为25.8μm。该方法不需要改变光路结构,测量过程简便,能很好地实现大尺寸高精度的绝对距离测量。 Aiming at the contradiction between resolution and maximum non-ambiguity distance when using a single-frequency femtosecond laser inter-mode signal, a method is proposed to measure the distance and synthesize the measurement results step by step by using microwave signals with different frequencies simultaneously method. The frequency of 100MHz and 1GHz were selected between the longitudinal mode beat signal measurement target distance, and then adjust the repetition rate of the femtosecond laser so that 1GHz longitudinal mode beat signal frequency change 1MHz measured again, with the help of the frequency change to be greater Of the synthetic wavelength, and finally the results of three measurements step by step synthesis, expanding the maximum non-ambiguous distance while ensuring high accuracy of the measurement results. The experimental results show that this method can extend the maximum un-ambiguity distance to 150m and the uncertainty of the target absolute distance measurement is 25.8μm. The method does not need to change the optical path structure, the measurement process is simple and can realize the large-size and high-precision absolute distance measurement well.