基于泰伯-莫尔条纹的激光波前曲率半径测量

Measurement of laser wavefront curvature radius based on Talbot-Moiré fringe

为了精确测量激光波前曲率半径,提出了基于泰伯-莫尔条纹技术的波前曲率半径测量方法,建立了激光波前曲率半径测量理论分析模型。对波前曲率半径与莫尔条纹倾角的关系、系统测量不确定度进行了分析,完成了激光波前曲率半径测量系统的设计,构建了测量系统,并对口径为200mm的激光发射系统的出射波前曲率半径进行了测量。结果表明,测量结果为498m时,测量重复性为0.2%,根据测量结果推算光束束腰位置与实际位置相对偏差为0.4%;并根据500m^3000m的测量结果对激光发射系统中出射波前曲率半径、物镜焦距、目镜位置等参量进行了校准,校准完成后与理论值的最大偏差为2%。该方法能够实现大口径激光发射系统出射波前曲率半径的高精度测量。

In order to measure curvature radius of laser wavefront accurately,one method based on Talbot-Moire fringe technique was proposed.The theoretical model of measuring wavefront curvature radius was established.The relationship between wavefront curvature radius and angle of Moire fringe,and the measurement uncertainty of the system were analyzed.The measurement system was designed and constructed.Wavefront curvature radius of laser system with the diameter of 200mm was measured.The results show that,the repeatability of measurement is 0.2%when the measured result is 498m.The relative deviation between the waist position and the actual position of the beam is 0.4%.According to the measured results of 500m^3000m,the parameters such as wavefront curvature radius,the focal length of object and the position of eyepiece are calibrated.After calibration,the maximum deviation from the theoretical value is 2%.The method can achieve high precision measurement of wavefront curvature radius of laser launching system with large aperture.