无透镜傅里叶变换数字全息术中非共面误差的自动补偿算法

无透镜傅里叶变换数字全息术对活细胞进行显微相衬成像测量时,由于细胞处于运动状态导致记录物体与参考点源难以共面,从而引入成像误差.本文提出了一种有效可靠的基于位相分布的自动对焦再现算法,只需通过一幅全息图,即可确定出记录距离的优化数值解,并结合一次位相线性拟合,成功补偿掉非共面误差.将这种算法应用到活体宫颈癌细胞的相衬成像实验中获得了较为理想的实验结果,表明了这种自动补偿非共面误差算法的可行性. 关键词： 数字全息 无透镜傅里叶变换全息 自动对焦 位相畸变校正

Automatic procedure for non-coplanar aberration compensation in lensless Fourier transform digital holography

When the lensless Fourier transform digital holography is applied to the microscopic phase-contrast imaging on live cells, the motion of cells will lead to a non-coplanary phenomenon between the object recorded and the reference source. This could result in the imaging aberration. An effective and robust autofocus procedure based on the phase distribution is presented in the paper. With the initial measurement of the distance between the reference source and the hologram, the optimal parameters corresponding to the phase-contrast image can be achieved by a single hologram combined with the linearity fitting. Lensless Fourier transform digital holographic system is built and the experiments on the phase-contrast imaging of the live cervical carcinoma cells are performed. Finally, the good experimental results are obtained. Both the theoretical analysis and the experimental investigation verify the feasibility and the validity of the automatic procedure for non-coplanar aberration compensation.