Liu Jianing, Meng Jin, Lyu Jiahang, Wang Shifeng
Appl Opt. 2022 Feb 10;61(5):1177-1182. doi: 10.1364/AO.447356.
The traditional multiposition method of the factor measurement system is a good method, but it is relatively time consuming, so it cannot meet the requirements of the transient test of a Gaussian beam. To solve this problem, a quadriwave lateral shearing interferometer and a wavefront construction method based on a difference Zernike polynomial are analyzed. This interferometer uses a special grating to select four replicas of the wavefront, and the interferogram generated by four replicas includes difference wavefront information. Then the difference Zernike polynomial method is used to analyze quadriwave lateral shearing interferograms. The characteristic parameters are obtained after finding the optimal terms of the Zernike polynomials. As a result, the errors of F-number, beam radius, and radius of curvature are 3.7%, 3.8%, and 0.6%, respectively, which verifies this method to calculate parameters of Gaussian beam. In addition, we also find that the shear amount has influence on the reconstructed wavefront. It is showed that as the amount of shear increases from 20 pixels to 90 pixels, the peak-to-valley (P-V) values and RMS values both gradually decrease with a nonlinear relationship, which could be used to decrease the error of wavefront reconstruction further.
传统的因子测量系统多位置方法是一种很好的方法，但相对耗时，因此无法满足高斯光束瞬态测试的要求。为了解决这个问题，分析了四波横向剪切干涉仪和基于差分泽尼克多项式的波前构建方法。该干涉仪使用特殊光栅选择波前的四个副本，四个副本产生的干涉图包含差分波前信息。然后使用差分泽尼克多项式方法分析四波横向剪切干涉图。在找到泽尼克多项式的最优项后获得特征参数。结果表明，F数、光束半径和曲率半径的误差分别为3.7%、3.8%和0.6%，验证了该方法用于计算高斯光束参数的有效性。此外，我们还发现剪切量对重建波前有影响。结果表明，随着剪切量从20像素增加到90像素，峰谷（P-V）值和均方根（RMS）值均呈非线性关系逐渐减小，这可用于进一步降低波前重建误差。
