构建了无透镜傅里叶变换数字全息实验系统, 实现了对一组生物样品特别是活体细胞的高保真度定量相衬成像。系统的简单性在于其数值再现过程只需直接对全息图进行一次快速傅里叶变换, 而对由此引入到相位像中的畸变, 则采用两步相减法予以校正。成像物体首先选用家蚊口器和洋葱表皮细胞的生物教学样片, 进而使用无标记的活体宫颈癌细胞。实验中, 不仅观察到了静态生物样品清晰的形态, 而且观察到活体细胞形态的动态变化, 充分表明了数字全息显微术应用于生物样品相衬成像的有效性。

A setup of the lensless Fourier transform digital holography is built to get the quantitative high-fidelity phase-contrast images of the biological samples. The basic advantage of such system is that the numerical reconstruction is directly applying only once fast Fourier transform to the intensity distribution of the hologram. However, the aberration appears in the phase image obtained by this kind of reconstruction algorithm and degrades the quality of the phase image seriously. Then, two-step subtraction method is applied to correct the phase aberration. In the experiments, at first two biological sample-plates for teaching are used as the objects, which are the mouse of the skeeter and the epidermal cells of the onion respectively. Then the living free-of-marker cervical carvinoma cells are presented as the object. Not only the clear morphologies of the static biological samples, but also the dynamic variations of the living cells are observed. The experimental results verify the validity of the digital holographic microscopy for the quantitative phase-contrast imaging of the biological samples.