反射式赝热光源散斑场的三维特性研究  

Three-Dimensional Characteristics of Speckle Field of Reflective Pseudothermal Light Sources

作　　者：卢立斌 谈志杰 喻虹[1,2] 韩申生 Lu Libin;Tan Zhijie;Yu Hong;Han Shensheng(Key Laboratory of Quantum Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences,Hangzhou 310024,Zhejiang,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海光学精密机械研究所量子光学重点实验室,上海201800 [2]国科大杭州高等研究院,浙江杭州310024 [3]中国科学院大学,北京100049

出　　处：《光学学报》2023年第9期78-84,共7页Acta Optica Sinica

基　　金：国家重点研发计划(2017YFB0503303);国家自然科学基金(11627811)。

摘　　要：傅里叶变换关联成像通常采用透射式赝热光源,但透射产生散斑的纵向尺寸过大限制了成像纵向分辨率且透射式赝热光的光通量较低,这对实现三维傅里叶变换关联成像造成了阻碍。为解决这一问题,理论推导了反射式赝热光源散斑场的光强涨落关联函数,给出了散射屏放置在不同空间位置和倾斜角度时的纵向散斑尺寸。同时,进行了基于统计光学的数值模拟,模拟结果与理论结果吻合。结果表明,通过减小散射角和增大散射屏方位角等方法可以有效降低观察点处的纵向散斑尺寸,从而提高纵向成像分辨率。Objective X-ray Fourier-transform ghost imaging(XFGI)is a new imaging technology that has emerged in recent years.Unlike traditional X-ray imaging,the resolution limit of this imaging method is theoretically limited only by the X-ray wavelength,which makes it possible to obtain higher spatial resolution than real-space imaging.Moreover,the phase information of the sample can also be obtained by this technique,which is of great significance for the imaging of weakly absorbing biological samples.However,the current FGI experiments mainly utilize transmissive pseudo-thermal light sources.The longitudinal size of the speckle generated by the transmissive source is too large,which limits the longitudinal resolution of imaging.Meanwhile,the luminous flux of transmissive pseudo-thermal light is low,which makes it difficult to carry out three-dimensional FGI.In contrast,the reflection method can provide more room for design and adjustment,allowing the longitudinal size of the speckle to be reduced.Furthermore,grazing incidence can be used to increase the reflected light flux and hence improve imaging quality.Therefore,the three-dimensional characteristics of the speckle field of the reflective pseudo-thermal light source are studied in hope of guiding and improving the light source system of three-dimensional FGI and thereby enhancing the longitudinal imaging resolution.Methods According to the Fresnel diffraction theory,the position of the pending sample is taken as the observation position,and the correlation function of the intensity fluctuation of the speckle field emitted by the scattering screen is derived.The speckle size is defined as the full width at half maximum of the speckle field.The longitudinal speckle size of speckle fields emitted by scattering screens at different spatial positions and inclination angles is discussed.Then,the numerical simulation based on statistical optics is carried out in the visible light region.Through the simulation,the light-field intensity distribution of the speckle field is o

关 键 词：成像系统 散斑场 赝热光 粗糙表面 关联成像 

分 类 号：O434.19[机械工程—光学工程]