基于单频正交线偏振光的激光波长直接测量方法

摘要

A laser wavelength direct measurement method based on the single frequency orthogonal polarized lights is proposed in this paper.The unknown laser wavelength is achieved by counting the integral fringes and determining the phase difference of two interference signals.Without using a reference laser, the proposed method is able to measure laser wavelength directly with a high accuracy in a wide range.Signal processing method for interference fringe counting is designed based on FPGA.The experimental result of He-Ne laser shows that the wavelength measurement error is less than 0.27 pm and the relative measurement uncertainty is 4.5×10-7.Therefore, the feasibility of the proposed laser wavelength direct measurement and the effectiveness of signal processing method are verified%提出了一种激光波长的直接测量方法,将对未知波长的测量转化为干涉条纹信号整周期计数和两路干涉信号相位差的测量,不需要参考光源,能实现激光波长的大范围高精度连续直接测量.介绍了系统的光路结构和激光波长直接测量原理,设计了基于FPGA的整数干涉条纹计数和小数干涉条纹相位差测量的干涉信号处理方法.对He-Ne激光器测量实验结果表明:激光波长测量误差小于0.27 pm,测量不确定度为4.5×10-7,由此验证了该方法的可行性以及干涉信号处理方法的有效性.