共查询到18条相似文献,搜索用时 126 毫秒
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利用部分相干光理论对多色光源照明下光栅的菲涅耳衍射进行了理论分析,得到了适用于任意发光类型(脉冲或连续发光)的多色光源的衍射光强的一般公式,理论结果表明菲涅耳衍射区的平均衍射光强的形式只与光源的频谱分布有关,这对借助于连续发光光源来研究脉冲光源照明下光栅的塔尔博特效应以及用来确定脉冲光源的性能参量提供了有力的参考依据。此外,详细讨论了光源的频谱分布对光栅塔尔博特效应的影响并进行了相应的数值计算。实验中通过选用不同频率的激光分别照明光栅,拍摄到对应于不同频率的衍射光强分布图像,从而间接获得多色光同时照明光栅时总的衍射光强分布。实验结果表明,理论和实验符合较好。 相似文献
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研究了菲涅耳衍射区和夫琅和费衍射区动态部分相干光散斑的特性.利用部分相干光互强度传播的理论,得出了在部分相干光照明时,由运动散射体产生的动态散斑光强时空交叉的自相关函数的一般形式,并由此得出了散斑沸腾和平移的一般规律.通过适当选择光源和调整光路参数,在实验上得到了菲涅耳和夫琅和费衍射区的部分相干光散斑,对夫琅和费面上的动态部分相干光散斑的平移和沸腾现象进行了定性研究;采用光子计数及数据自动采集的方法,对部分相干光散斑随时间的演化及动态部分相干光散斑的沸腾进行了定量测量.这些实验结果与理论结果相符合.
关键词:
部分相干光动态散斑
时空交叉相关函数
沸腾 相似文献
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部分相干光经柱面球差透镜聚焦所产生的焦移 总被引:7,自引:7,他引:0
利用Collins公式得出光强均匀部分相干光经柱面球差透镜聚焦后的轴上光强分布,并通过数值模拟的方法研究了入射光的菲涅耳数、相干度和透镜的球差对轴上点光强分布的影响.结果显示,当菲涅耳数较小、空间相干度较小的部分相干光经无球差透镜聚焦时,轴上点光强分布会产生焦移现象,而当部分相干光被球差透镜聚焦时,也会有焦移现象产生. 相似文献
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部分相干光被环形透镜聚焦而产生的焦移 总被引:2,自引:0,他引:2
从理论上研究部分相干光被一环形透镜聚焦,在焦点附近的轴上点的光强分布。研究结果表明,当部分相干光被一环形透镜聚焦时,最大聚焦光强不在几何焦点,而是位于透镜与几何焦点之间,出现焦移现象。并且,焦移量不仅依赖于透镜外半径的菲涅耳数,还依赖于部分相干光的空间相干度和中心拦截比。透镜的菲涅耳数越小,焦移越大;部分相干光的空间相干度越低,焦移越大。当菲涅耳数一定时,环形透镜的中心拦截比越大,焦移越大;当空间相干度很小时,情况就变得比较复杂。 相似文献
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研究了不同畴腐蚀深度的掺镁铌酸锂二维六角可调阵列光分束器的分数Talbot效应.对不同Talbot分数β和不同畴腐蚀深度的阵列光分束器Talbot衍射像进行了数值模拟理论研究.模拟结果表明,Talbot分数β可以改变Talbot衍射像的周期及结构分布,而畴腐蚀深度可有效调制衍射像的光强分布.在理论研究的基础上,设计并制备了具有不同畴腐蚀深度的掺镁铌酸锂二维六角阵列光分束器,对其在不同Talbot分数β条件下的分数Talbot效应进行了通光实验研究,实现了畴腐蚀阵列光分束器对近场Talbot衍射光强分布的调制,实验结果与理论研究结果一致. 相似文献
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基于高斯谢尔光束的相干模式分解理论和波动光学,建立了部分相干同步辐射硬X射线光束通过光学器件的传播模型。模拟了微聚焦X射线光束照射下光栅的分数塔尔博特效应,得到了聚焦光束的光强分布和相干特性变化,并分析了散焦光束入射下的光栅自成像。然后通过模拟准直光束入射下的光栅塔尔博特效应,得到了不同传播距离处自成像条纹的变化情况,分析了影响光栅自成像条纹形状的因素。通过光栅衍射条纹测量同步辐射相干度,发现对矩形相位光栅来说,应该对衍射图样进行傅里叶分解,求出各级傅里叶系数随传播距离的变化曲线,从而得到入射光束相干特性。 相似文献
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The Fresnel theory of the Talbot effect of the grating is reviewed in this paper, and the general formula of the Fresnel diffraction of the grating with finite aperture size is presented. The aperture effect of the grating on the Talbot image is discussed and a number of numerical calculations are performed. The variation rule of the diffraction intensity distribution at the Talbot distance with the aperture size of the grating and the case at different Talbot distances are obtained through the calculations, and the corresponding explanations of these phenomena are given in this paper. We think that these discussions provide the theoretic basis for the practical application of the Talbot effect of the actual grating. 相似文献
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Denis A. Ikonnikov Sergey A. Myslivets Nikolay N. Davletshin Filipp A. Baron Vasily G. Arkhipkin Andrey M. Vyunishev 《Annalen der Physik》2023,535(3):2200480
The near-field effect of diffraction image self-reproduction or self-imaging of a periodic grating illuminated by quasi-monochromatic wave is well-known as the Talbot effect. Introducing a dislocation to a periodic structure provides a fork-shaped modulation of the phase/amplitude, which produces discrete diffraction pattern in a far-field consisting of optical vortices. In this paper, Fresnel diffraction at amplitude fork-shaped grating is theoretically and experimentally studied. The coexistence of spatial ordering and local violation of translational symmetry of the structure manifests itself in a strict diffraction pattern consisting of optical vortices in the far-field, which is shown to be accompanied by formation of a spatially ordered intensity distribution in the near-field, reminiscent the Talbot carpets for periodic structures. These results demonstrate the first evidence of Talbot effect occurred under light diffraction at fork-shaped gratings, being promising for deep understanding of near-field singular optics phenomena. 相似文献
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T. Asakura 《Optics Communications》1973,8(1):33-36
The intensity distribution in the Fresnel diffraction pattern of a slit aperture illuminated with partially coherent light is obtained, as a function of the coherence condition across the aperture, by evaluating the formula developed in a previous paper. It is shown that the Fresnel diffraction pattern is affected by the coherence condition of illumination across the aperture and its form. 相似文献
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We report the first experimental observation of quantum Talbot effects with single photons and entangled photon pairs. Both the first- and second-order quantum Talbot self-images are observed experimentally. They exhibit unique properties, which are different from those produced by coherent and incoherent classical light sources. In particular, our experiments show that the revival distance of two-photon Talbot imaging is twice the usual classical Talbot length and there is no net improvement in the resolution, due to the near-field effect of Fresnel diffraction, which is different from the case of previous proof-of-principle quantum lithography experiments in the far field. 相似文献