基于单频正交线偏振光的激光波长测量方法研究

发布时间：2018-07-07 22:42

本文选题：激光波长测量 + 迈克尔逊干涉　；参考：《浙江理工大学》2017年硕士论文

【摘要】：长度基准是保证量值准确和实现互换性的基础,现行长度基准采用光的波长作为长度单位。激光波长作为几何测量的基准,被广泛应用于长度、角度、平面度、直线度和垂直度等几何量的测量,是精密计量、精密机械和微电子工业领域重要的测量参数。因此精确地测量波长大小是保证几何量测量准确性和量值溯源的关键。本文提出了一种基于单频正交线偏振光的激光波长直接测量方法,在光路中构建了两套迈克尔逊干涉仪,通过压电陶瓷驱动器调制两套干涉仪的参考镜,将对未知波长的测量转化为干涉条纹信号整周期计数和干涉信号相位差的测量。主要研究工作如下:设计了基于单频正交线偏振光的激光波长测量系统的光路结构,并结合光路结构对测量原理进行了详细分析;设计了信号预处理电路,用于调整输出电压范围及改善电路输出特性;利用级联积分梳状(Cascaded Integral Comb,CIC)数字滤波算法对信号进行滤波处理,从而改善了信号质量;对造成相位差测量误差的原因进行了分析并进行补偿,从而实现了相位差的高精度测量;给出了整周期计数方法及与小数计数整合的方法;利用整周期计数模块对参考镜运动方向进行判断从而实现了在参考镜特定的运动方向上对相位差进行测量;利用Visual Basic语言进行了上位机软件的设计。为验证本文研制的基于单频正交线偏振光的激光波长测量系统的有效性,分别进行了以下实验:(1)相位差检测及补偿实验,以10°为步长进行相位差检测补偿实验,补偿前相位差测量误差平均值为2.38°,补偿后相位差测量误差平均值为0.22°。(2)整周期计数值及与小数计数值整合实验,以5 mm为步长进行了整小数结合实验,整小数值与理论值差值的绝对值均小于0.5。(3)系统稳定性实验,进行了相位差连续测量实验,在三十分钟内相位差变化较小,证明系统稳定性良好。(4)测量镜运动不同距离对波长测量精度影响实验,分别进行了测量镜运动100 mm、150 mm、200 mm、250 mm的波长测量实验。波长测量不确定度分别为1.38×10-6、9.86×10-7、7.80×10-7、5.36×10-7。(5)激光器波长测量应用实验。测量了ZYGO激光器的波长,波长测量不确定度为5.17×10-7。
[Abstract]:The length reference is the basis to ensure the accuracy and interchangeability. The current length reference uses the wavelength of light as the unit of length. Laser wavelength, as a standard of geometric measurement, is widely used in the measurement of geometric parameters such as length, angle, flatness, straightness and perpendicularity. It is an important measurement parameter in the field of precision metrology, precision machinery and microelectronics industry. Therefore, accurate measurement of wavelength is the key to ensure the accuracy and traceability of geometric measurements. In this paper, a direct measurement method of laser wavelength based on single frequency orthogonal linear polarized light is proposed. Two sets of Michelson interferometers are constructed in the optical path, and two reference mirrors of the interferometer are modulated by piezoelectric ceramic driver. The measurement of unknown wavelength is transformed into the whole period count of interference fringe signal and the measurement of phase difference of interference signal. The main research work is as follows: the optical circuit structure of the laser wavelength measurement system based on single frequency orthogonal line polarized light is designed, and the principle of the measurement is analyzed in detail, and the signal preprocessing circuit is designed. It is used to adjust the output voltage range and improve the output characteristics of the circuit, and the signal quality is improved by using the cascade integral CombCIC digital filter algorithm to filter the signal. The reason of the error of phase difference measurement is analyzed and compensated to realize the high precision measurement of phase difference, the method of integral period counting and the method of integrating with fractional count are given. The whole cycle counting module is used to judge the direction of motion of the reference mirror so as to measure the phase difference in the specific direction of the reference mirror, and the software of upper computer is designed by using Visual basic language. In order to verify the effectiveness of the laser wavelength measurement system based on single frequency orthogonal linear polarization, the following experiments were carried out: (1) the phase difference detection and compensation experiments were carried out with 10 掳step. The average value of phase difference measurement error before compensation is 2.38 掳, and that of phase difference measurement error after compensation is 0.22 掳. (2) the integral period counting value and the numerical integration experiment with decimal count are carried out with 5 mm step size. The absolute value of the difference between the whole value and the theoretical value is less than 0.5. (3) in the system stability experiment, the phase difference is measured continuously, and the change of the phase difference is small in 30 minutes. It is proved that the stability of the system is good. (4) experiment on the influence of different distance of motion of measuring mirror on the accuracy of wavelength measurement is carried out, and the wavelength measurement experiment of 100 mm / 150 mm / 200 mm / 250 mm is carried out respectively. The uncertainty of wavelength measurement is 1.38 脳 10-6, 9.86 脳 10-7, 7.80 脳 10-7 and 5.36 脳 10-7, respectively. (5) the wavelength measurement experiment of laser. The wavelength of ZYGO laser is measured. The uncertainty of wavelength measurement is 5.17 脳 10 ~ (-7).
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN24

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