Liao Yongchao, Zhang Zhiping, Wang Ning, Chen Zhang, Hao Lingling, Yang Xiaofeng
Appl Opt. 2022 May 1;61(13):3648-3655. doi: 10.1364/AO.452854.
A dual-frequency laser interferometer is an important instrument that can provide a meter-level measurement range with nanometer-level measurement accuracy at several meters per second measurement speed. The measurement accuracy of the dual-frequency laser interferometer plays a vital role based on laser wavelength, which is easily affected by environmental factors, so the air refractive index needs to be corrected. In this paper, an improved Edlen empirical formula air refractive index compensation method is introduced, in which a particle swarm optimization algorithm is used to optimize the Edlen formula by adjusting the compensation model online according to the compensation effect to adapt to different environmental conditions. The experimental results show that the root mean square error of the interferometer compensated for by the unoptimized Edlen formula can be reduced by 79.3% and 72.1% under different optical path lengths, and by 90.7% and 91.9% after compensation by the optimized Edlen formula, which means that the average compensation effect is improved by about 20%.
双频激光干涉仪是一种重要的仪器，它能够在每秒数米的测量速度下提供米级的测量范围和纳米级的测量精度。双频激光干涉仪的测量精度基于激光波长起着至关重要的作用，而激光波长很容易受到环境因素的影响，因此需要对空气折射率进行校正。本文介绍了一种改进的埃尔德伦经验公式空气折射率补偿方法，该方法采用粒子群优化算法，根据补偿效果在线调整补偿模型来优化埃尔德伦公式，以适应不同的环境条件。实验结果表明，在不同光程长度下，未优化的埃尔德伦公式补偿后的干涉仪均方根误差可降低79.3%和72.1%，优化后的埃尔德伦公式补偿后可降低90.7%和91.9%，这意味着平均补偿效果提高了约20%。
