大视场超分辨率同轴数字全息成像方法研究

项目名称： 大视场超分辨率同轴数字全息成像方法研究

项目编号： No.61307010

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 戎路

作者单位： 北京工业大学

项目金额： 26万元

中文摘要： 针对探测器性能和计算能力对数字全息的制约，本项目基于亚像素微位移方法构建大视场超分辨率的同轴数字全息成像系统，利用低分辨率全息图序列重建出高分辨率全息图，通过相位复原和相位拼接实现大视场全息图的快速再现。首先，研究能够实现全息图亚像素微位移的光路结构，通过部分相干光扩展点光源的横向移动获取高质量全息图序列；在此基础上，通过特征匹配算法对序列自动配准，实现全息图的超分辨率空域重建；随后，通过基于初始值优化的相位快速复原算法，快速再现得到子视场物光波定量复振幅分布；最后，利用相减算法消除坐标差异，完成超大尺寸相位再现像拼接，实现亚微米级横向分辨率、纳米级相位测量精度、厘米级视场范围，快速再现的无损定量相衬成像。本项目能为微纳元件的研发、制造与评估提供一种大视场高分辨率检测方法，还能够作为便携式仪器实现现场原位显微观测，并应用在太赫兹波、X射线、γ射线等其它重要波段的三维成像和检测领域。

中文关键词： 数字全息；相位复原；太赫兹成像；相衬成像；超分辨率

英文摘要： With the fast development of charge-coupled device (CCD) and computer science, holograms can be recorded and reconstructed numerically without photographic plates. However, restricted by the finite size of CCD, the resolution of the reconstructed image in digital holography is usually lower than that in traditional optical holography and the reconstrcuted area is also quite limited. We propose a wide field-of-view super-resolution in-line digital holographic microscopy, in which a super resolution (SR) in-line hologram is recovered from a series of low resolution (LR) sub-pixel shifted holograms, and reconstructed by a hybrid phase retrieval algorithm using premium initial guess. Firstly, in order to record the LR holograms, an experimental setup based on lens-free in-line digital holographic microscope is established. The coherent noise in the reconstructed images is greatly suppressed via partially-coherent point illumination source. Secondly, these LR holograms is automatic registrated using scale invariant feature transform (SIFT) algorithm and recovered as a SR hologram. Thirdly, to reduce computional load, the SR hologram is divided into sub-field holograms. The complex amplitude of the object wavefront in every sub-field is retrieved using a hybrid phase retrieval algorithm, in which a premium initial gue

英文关键词： digital holography；phase retrieval；terahertz imaging；phase-contrast imaging；super-resolution