摘要
作为复光场显微成像的一种新技术,菲涅耳非相干关联全息术(Fresnel incoherent correlation holography,FINCH)因其非相干光记录的特点在近年来受到关注.FINCH作为一种新型非相干全息系统,如何设计光路实现其最佳的分辨率是一个关键问题.然而,针对这个问题的讨论,目前已有文献存在不同的观点,有关FINCH最佳分辨率的成像条件仍有待研究.全息图有效孔径大小是决定全息成像系统分辨率的重要因素,在FINCH系统中,全息记录距离的变化则会引起全息图有效孔径发生变化,全息图的有效孔径大小不仅与光路各元件的孔径有关,还与相干光波相互干涉叠加区域的面积以及图像传感器的像素间距等因素有关.本文基于波动光学理论,结合FINCH全息图的波带结构特征,研究了FINCH全息图的有效孔径.研究发现数字全息记录相机的像素化特性是影响FINCH成像分辨率的决定性因素,并进一步通过数值模拟和光学实验验证了理论分析结果:全息图记录距离(Z_h)等于空间光调制器加载的衍射透镜焦距(f_d)时,FINCH系统的再现像将会达到最佳横向分辨率,且分辨率随成像距离|Z_h-f_d|的增大而降低.
As a new technique of photomicrography of complex optical field, the Fresnel incoherent correlation holography(FINCH) is particularly attractive in recent years because of its incoherent optical recording characteristics. For a new image recording and reconstruction system, a key concern is how to configure the experimental layout of FINCH by using available optical elements to achieve optimal resolution. However, in previous reports, there exist different viewpoints about this issue, and the imaging conditions of the best resolution remain to be clarified. As is well known, the imaging resolution is affected by the effective aperture of hologram and the change of the recording distance between spatial light modulator(SLM) and image sensor(CCD) can cause the hologram aperture to change. In the FINCH system the effective aperture of hologram is related not only to the aperture influence of each element used in the recording system, but also to the overlapping area of interference between the signal and reference wave and the pixel spacing of the image sensor. In previous reports, the researchers mainly used the ray-tracing method to discuss the effective aperture radius of hologram by ignoring the influences of the diffraction of light wave and the pixel spacing size of image sensor on the aperture of hologram. Based on the theories of wave optics we carry out a thorough investigation into the effective aperture of FINCH. We find that the pixelization of the image sensor, e.g. CCD, is a decisive factor influencing the resolution of FINCH, and we adopt numerical simulations and optical experiments to further verify the theoretical conclusions that the optimal lateral resolution of FINCH is achieved only if the recording distance(Z_h) is equal to the focal length(f_d) of diffractive lens displayed on a spatial light modulator;the resolution is deteriorated with the increase of |Z_h-f_d|. From the viewpoint of Fourier optics, the smaller the imaging distance |Z_h-f_d|, the larger the aperture angle of hologram(≈R_h
作者
潮兴兵
潘鲁平
王子圣
杨锋涛
丁剑平
Chao Xing-Bing;Pan Lu-Ping;Wang Zi-Sheng;Yang Feng-Tao;Ding Jian-Ping(National Laboratory of Solid State Microstructures,School of Physics,Nanjing University,Nanjing 210093,China;College of Science,Jiujiang University,Jiujiang 332005,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第6期95-104,共10页
Acta Physica Sinica
基金
国家重点研发计划(批准号:2018YFA0306200)
国家自然科学基金(批准号:91750202
11534006)资助的课题~~
关键词
全息
分辨率
波带片
液晶器件
holography
resolution
zone plates
liquid-crystal devices
