相位拼接技术在数字全息中的应用

Application of Phase Stitching Technique on Digital Holography

在确保较高分辩率的前提下,提出了一种相位拼接技术以解决数字全息技术中扩大测量面积的瓶颈问题.在全息数字图记录过程中,确保相邻子孔径间具有重叠区域;拼接中采用相关算法确定重叠区域,并利用再现像重叠区域具有相同信息的特点使用最小二乘方法消除由于孔径的移动所产生的倾斜误差;相关计算和最小二乘反复迭代把相邻再现像精确统一到一个坐标系下,从而实现测量面积的扩展.以平面物体的测量为例建立了数字全息相位拼接技术的理论模型,完成了对相位物体的2×2拼接模拟,并在对标准相位板2×2的拼接实验中获得了较好的拼接效果.

A phase stitching technology in digital hologram which can enlarge the testing area with a high resolution is proposed.In digital hologram registering,the common overlapped area should be ensured between two adjacent apertures.Correlation algorithm is used to confirm the accurate overlapped area while least-square algorithm is used to remove the tilt and piston error.So,the adjacent apertures are united to the standard coordinate by iterating the correlation algorithm and the least-square algorithm.Thus,the testing area is enlarged by this technology.Taking plane image measurement as example,the theory of holographic phase stitching is presented and the relevant 2×2 stitching simulation is performed using a phase object.And,an experiment for standard phase plate is performed and a favorable stitching result is obtained.