连续太赫兹波数字全息生物样品成像方法研究

项目名称： 连续太赫兹波数字全息生物样品成像方法研究

项目编号： No.61475011

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 王大勇

作者单位： 北京工业大学

项目金额： 94万元

中文摘要： 太赫兹波具有独特的低能性、高穿透性、惧水性等成像特性，在生物医学检测等领域具有重要的应用。本项目研究连续太赫兹波段的数字全息成像方法，旨在针对生物样品，发展一种无损无标记的、实时全视场、高分辨率成像技术。 首先，基于太赫兹波的传输理论和相干特性，研究连续太赫兹波数字全息成像机理，分析成像空间分辨率、视场、焦深与景深的内在制约关系，结合生物样品的实验条件，优化成像系统设计。其次，基于亚像素微位移及滤波处理，获取高质量的太赫兹全息图。随后，在样品照明光路中引入二维光栅收集衍射高频分量，发展相位恢复的外推算法，获得突破探测器参数限制的高分辨率、高保真度的定量幅值和相位分布信息。最后，构建实际生物样品的成像装置，开展动态定量观测研究，建立太赫兹波振幅和相衬图像信息与样品生理学参数的联系。本项目的开展将为现代生物医学的无损可视化研究提供一种太赫兹波段的高分辨率、动态连续的定量检测方法。

中文关键词： 太赫兹成像；数字全息术；生物成像；相衬成像；相位恢复

英文摘要： Terahertz (THz) radiation, due to its unique characters of low-energy, high-penetration, water-absorption, etc, has been widely used in biomedical imaging. A high-resolution, non-invasive, no-label, real-time, whole-field imaging method is proposed for biological samples based on continuous-wave (CW) THz digital holography. Firstly, based on the transmission and coherent characteristics of CW THz radiation, we would investigate the imaging mechanisum of the terahertz digital holography with the exact diffraction propagation theory, and quantitatively assess the inherent relationship of the spatial resolution, field of view, depth of focus and depth of field, which are key issues for evaluating the imaging system. Correspongingly, the optimization of the imaging system is carried out considering the measurement conditions of biological samples. Secondly, based on the sub-pixel shifting and the filtering process, high quality terahertz digital holograms would be obtained. Also,in order to increase the numerical aperture of the imagin g system, the two-dimensional grating would be applied to collect high-frequency components of the object wavefront. The phase retrieval algorithm based on extrapolation would be develeoped to recover the phase information on the recording plane and overcome the limitation of the detector. The high-resolution, high-fidelity quantitative distribution of the amplitude and phase information would be therefore obtained from the THz holograms. The experimental setup will be built with the CW THz source and the pyroelectric array camera, and applied for the practical biological imaging, including the dynamic quantitative observation. With the results, we would establish the relationships between THz complex amplitude distribution (both amplitude and phase contrast images) and physiological parameters of biological samples, which are very useful for the biomedical science. The project will and shall provide a high-resolution non-destructive quantitative THz imaging method for visualized biomedical research.

英文关键词： Terahertz imaging;Digital Holography;Biomedical imaging;Phase-contrast imaging;Phase retrieval