Wang Daodang, Xu Yangbo, Liang Rongguang, Kong Ming, Zhao Jun, Zhang Baowu, Li Wei
Opt Express. 2016 Apr 4;24(7):7079-90. doi: 10.1364/OE.24.007079.
It is a key issue to measure the point-diffraction wavefront error, which determines the achievable accuracy of point-diffraction interferometer (PDI). A high-precision method based on shearing interferometry is proposed to measure submicron-aperture fiber point-diffraction wavefront with high numerical aperture (NA). To obtain the true shearing point-diffraction wavefront, a double-step calibration method based on three-dimensional coordinate reconstruction and symmetric lateral displacement compensation is proposed to calibrate the geometric aberration in the case of high NA and large lateral wavefront displacement. The calibration can be carried out without any prior knowledge about the system configuration parameters. With the true shearing wavefront, the differential Zernike polynomials fitting method is applied to reconstruct the point-diffraction wavefront. Numerical simulation and experiments have been carried out to demonstrate the accuracy and feasibility of the proposed measurement method, and a good measurement accuracy is achieved.
测量点衍射波前误差是一个关键问题，它决定了点衍射干涉仪（PDI）可达到的精度。提出了一种基于剪切干涉测量法的高精度方法，用于测量具有高数值孔径（NA）的亚微米孔径光纤点衍射波前。为了获得真实的剪切点衍射波前，提出了一种基于三维坐标重建和对称横向位移补偿的双步校准方法，以在校高NA和大波前横向位移情况下校准几何像差。该校准无需任何关于系统配置参数的先验知识即可进行。利用真实的剪切波前，应用差分泽尼克多项式拟合方法来重建点衍射波前。进行了数值模拟和实验，以证明所提出测量方法的准确性和可行性，并取得了良好的测量精度。
