一种实现CCD亚像元位移分辨率的新方法

A New Method with CCD Subpiexl Resolution

基于 CCD子窗口内四个像限的光积分量随目标位置而变化的机理 ,可从摄取的 CCD数字图像提取目标的位移信号 ,本文提出一种新的方法可实现目标位移探测的亚像元分辨率。理论及实验结果表明 ,对于直径为 1μm的球体而言 ,在± 40 0 nm的范围内 ,光积分量的变化同球体的位移关系具有良好的线性度。物方和像方位移分辨率分别可达 1nm和 1/ 3 0个像元宽度 ,可满足光镊系统位移测量要求。

Subpixel resolution can be achieved by deriving position signal of objective from digital images based on photons accumulated of each quadrant of a CCD sub window varying with the position shift of objective watched.Theory and experiment results indicate that the change of photons accumulated show good linearity when a 1μm diameter sphere moves within ±400μm.The resolutions at objective plane and image plane can reach 1nm and 1/30 pixel,respectively.This method can satisfy the application of optical tweezers.