提出一种基于四波前剪切干涉的显微定量相位成像方法, 使用棋盘型位相光栅获得生物样品的干涉图, 采用快速傅里叶法解得相位信息.实验测量可变形镜产生的随机波前, 与ZYGO干涉仪的对照结果表明相位测量误差不超过3%, 验证了四波前剪切干涉仪的相位探测精度.建立了一套基于四波前剪切干涉技术的显微定量相位成像系统, 以小鼠肝癌活体细胞为样品, 获得了清晰的强度图像和相位图像.实验结果表明基于四波前剪切干涉技术的系统可以实现高精度的定量相位成像, 适用于生物活体细胞的相位显微成像研究.

A micro quantitative phase imaging method based on quadriwave shearing interferometry is proposed. A chessboard phase grating is used to get the interferogram of biological samples, and the phase information is obtained by the fast Fourier transform method. A pack of wavefront produced by the micro-electromechanical systems is measured, and the ZYGO interferometer is used for comparision. The error of phase measurement is not more than 3%, which verifies phase detection accuracy of the quadriwave shearing interferometer. A quantitative phase imaging system based on the quadriwave shearing interferometry is established, and a clear quantitative phase image is obtained from murine hepatoma cell. The experimental results show that the system based on the quadriwave shearing interferometry can achieve high-precision quantitative phase imaging, and is suitable for phase imaging of biological living cells.