针对生物活细胞的观测,基于预放大离轴光路设计和构建了一套倒置式像面数字全息显微成像系统,该系统的全息图记录平面与物体的像面重合,无需光学衍射传播步骤,简化了再现过程。对于引入到相位像中的畸变,采用简单快速的曲面拟合法予以校正;并利用分辨率板对系统实际分辨率进行测定,该系统可以分辨的最小细节信息为0.87 μm。以老鼠的大脑海马区神经元活细胞为成像物体,实现了其在自然状态下的定量相衬成像,清晰观察到了海马区神经元活细胞的胞体、树突等形态结构,获得了细胞形态的基本参数。结果表明,数字全息术可用于神经元等活体细胞的定量形态检测,为生物医学领域的细胞形貌分析提供一种无损的相衬成像手段。
In accordance with the need of observing and analyzing living cells, based on the pre-magnification off-axis digital holographic theory, an inverted setup of pre-magnification off-axis image plane digital holographic microscopy is designed and built, where the image plane of the microscope objective is coplanar with the recording plane of the hologram. Therefore, the step of the numerical diffraction propagation by the computer is needless and the numerical reconstruction is simplified. Meanwhile, the simple and fast surface fit method is applied to correct the phase aberration. Furthermore, the actual resolution is measured by using the USAF resolution mask, which is 0.87 μm. Finally, the quantitative phase-contrast images of the living hippocampal neuron cells in the natural state are achieved. From the experimental results, the structures of cells including the cell body and the dendrite are observed. The basic parameters of the cell morphology are also obtained. The results show that the digital holography is useful in the quantitative morphological detection of living cells and it provides a non-destructive phase-contrast imaging approach for the cell morphological analysis in the field of the bio-medical research.