光学三维显微成像可以无接触、高分辨的测量样品的三维信息，是科学研究和高精密加工制造等领域中必不可少的辅助工具。但是普通的光学三维显微只能观测样品的三维形貌，不能无标记的测量透明样品的内部折射率分布。而折射率是反应样品内在物理特性的重要参数。为了解决这一问题，本项目提出了一种基于剪切干涉和压缩感知的光学衍射层析显微方法来实现对透明样品内部三维折射率分布的无标记快速定量观测。利用光栅衍射和四波剪切来构建物参共路的衍射层析显微装置；通过空间光调制器精确、快速的改变光束的照明方向来获得样品在不同照明角度下的定量相位信息并利用压缩感知从少量的记录数据中高精度定量再现样品内部的折射率分布；最后通过彩色CCD不同颜色通道的复用，提高装置的观测速度。该方法可以为微观科学的研究提供一种结构简单且稳定性高的无标记三维定量成像方法和工具。

Optical three-dimensional microscopy is an indispensable auxiliary tool for scientific research and high-precision manufacturing since it can measure the three-dimensional information of samples quantitatively with non-contact and high-resolution. However, the common optical three-dimensional microscopy can only observe the 3D shape and cannot measure the internal refractive index distribution of the sample without a label. The refractive index is an important parameter which reflects the intrinsic physical properties of the sample. This project proposes new optical diffraction tomography, which combining shearing interferometry and compression sensing, to quantitatively and label-free measure the internal refractive index distribution of the transparent sample. Based on the grating diffraction and four-wave shearing interferometry, a common-path diffraction tomographic microscope will be build and the angle of the illumination light can be accurately and quickly adjusted by a spatial light modulator. Then, the quantitative phase images of the sample under different illumination angles can be obtained. By using the compressed sensing technology, the internal refractive index distribution of the sample can be quantitatively reconstructed from the limited phase images. The measurement speed can be improved by multiplexing the different color channels of the color CCD. The proposed method provides a new simple and stable label-free three-dimensional quantitative imaging method for micro-science research and other applications.