脉宽对超快激光平衡光学互相关测距影响的研究

采用基于平衡光学互相关的超快激光绝对距离测量方法对大气中一段15m的空间距离进行了测量。仿真了不同脉冲宽度、不同光强损耗对平衡互相关信号的影响,理论分析表明脉宽展宽对平衡互相关信号影响较大。采用中心波长为1037nm、重复频率为260MHz的超快激光器光源,搭建了测距系统。实验验证了在脉宽分别为1.44ps、132fs时,对平衡互相关信号的影响,实验结果符合理论分析。研究了不同脉冲宽度对测量分辨力的影响,结果显示,采样时间为5ms,脉宽为1.44ps,测量分辨力不低于50μm;而当脉宽为132fs时,测量分辨力优于5μm。

The effect of pulse width on distance measurement based on the balanced optical cross-correlation technique with ultrafast laser

A distance of about 15m is measured using the method based on the balanced optical cross-correlation technique with ultrafast laser.The effects of varying pulse width and intensity attenuation on the signal of balanced optical cross-correlation are simulated, which shows that the pulse width has greater impact.An ultrafast laser is used to produce measurement pulses whose output spectrum is centered at a 1037 nm wavelength and the pulse repetition rate is initially set at 260 MHz in the measurement system.In the experiments, the change of the signal of balanced optical cross-correlation are discussed when the pulse widths are 132fs and 1.44ps respectively, it proves that the results accord with the theoretical simulation.The measurement resolutions are experimentally tested, it reaches 50μm for a 1.44ps pulse at a sampling rate of 5ms, and it improves to 5μm when the pulse width is 132fs.