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高斯光束菲涅耳圆孔衍射轴上的光强分布 总被引:1,自引:1,他引:0
本文从惠更斯-菲涅耳原理的数学表达式出发,在菲涅耳圆孔衍射的情况下求出了高斯光束入射时轴上光强分布的解析表达式,并对比平面波和球面波入射的情况进行了分折讨论. 相似文献
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验证菲涅耳圆孔衍射中的一个重要结论温淑珍(黑龙江绥化师专)在菲涅耳圆孔衍射中,如图1,圆孔CC’露出的波阵面,在与点光源P0处同一轴上的P点引起的光振动的振幅”’为其中山和山分别为波阵面上相对于PO和P所作的第一个和最后一个菲涅耳半波带单独对该点引起... 相似文献
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在菲涅耳圆孔衍射(图1)中,根据圆形菲涅耳半波带的划分,可知没有遮蔽的整个波阵面在P_0点引起的光强只有使圆孔露出第一个半波带的那一小部分波阵面在同一点引起光强的四分之一。笔者对此“四分之一光强”的结论作了实验验证。该实验的主要方法是,设计一个能露出第一个半波带的菲涅耳圆孔衍射系统,以线性光电探头测出被测点光强引起的光电流,再与 相似文献
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根据波动光学的理论,对菲涅耳近场衍射公式误差相位的影响进行了分析。以单缝衍射为例,讨论了误差相位与计算精度的联系。结合菲涅耳线波带片焦面光强分布的计算,对比了菲涅耳衍射公式与基尔霍夫衍射公式的计算结果,说明在不满足误差相位近似条件下使用菲涅耳衍射公式带来的影响。最后对影响波带片焦面光强分布的几个因素进行了讨论。 相似文献
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We study the Fresnel diffraction of Gaussian beam truncated by one circular aperture, and give the general analytic expression of the Fresnel diffraction of truncated Gaussian beam denoted by Bessel functions. Then the characteristic of the axial diffraction fluctuation and the influence of the caliber of the circular aperture and the wave waist of Gaussian beam on the diffraction distributions are discussed, respectively. Through the numerical calculations, the characteristics of the transverse diffraction are presented and the relationship of the fluctuation of the transverse diffraction profile and the position of the axial point is shown. The physical origin of the fluctuation of Fresnel diffraction intensities of truncated Gaussian beam is expressed in terms of Fresnel half-zone theory. These phenomena and the conclusions are important for the measurement of the parameters of the beam and its applications. 相似文献
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导出非傍轴区轴上点菲涅尔圆孔衍射的精确解析式,并用计算机模拟出不同参数下的各种衍射光强曲线。通过理论分析,揭示出菲涅尔圆孔衍射更深刻的物理内涵。 相似文献
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Recurring to the characteristic of Bessel function, we give the analytic expression of the Fresnel diffraction by a circular aperture, thus the diffractions on the propagation axis and along the boundary of the geometrical shadow are discussed conveniently. Since it is difficult to embody intuitively the physical meaning from this series expression of the Fresnel diffraction, after weighing the diffractions on the axis and along the boundary of the geometrical shadow, we propose a simple approximate expression of the circular diffraction, which is equivalent to the rigorous solution in the further propagation distance. It is important for the measurement of the parameter of the beam, such as the quantitative analysis of the relationship of the wave error and the divergence of the beam. In this paper, the relationship of the fluctuation of the transverse diffraction profile and the position of the axial point is discussed too. 相似文献
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Axial intensity distribution behind a Fresnel zone plate 总被引:1,自引:0,他引:1
An analytical expression based on an improved Rayleigh–Sommerfeld diffraction formula with evanescent term is derived for analyzing the axial light intensity distribution throughout the whole space behind a Fresnel zone plate. The effects of the number of Fresnel zones and the size of aperture on the axial intensity distribution are calculated for two kinds of Fresnel zone plate with larger and smaller aperture. The validity of the general formulae for calculating the focal lengths and the relative intensities of the foci of a Fresnel zone plate is analyzed. 相似文献
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Based on the vectorial Rayleigh diffraction integral and the hard-edge aperture function expanded as the sum of finite-term complex Gaussian functions, an approximate analytical expression for the propagation equation of vectorial Gaussian beams diffracted at a circular aperture is derived and some special cases are discussed. By using the approximate analytical formula and diffraction integral formula, some numerical simulation comparisons are done, and some special cases are discussed. We find that a circular aperture can produce the focusing effect but the beam becomes the shape of ellipse in the Fresnel region. When the Fresnel number is equal to unity, the beam is circular and the focused spot reaches a minimum. 相似文献
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Based on the generalized Huygens–Fresnel diffraction integral and the expansion of the hard aperture function into a finite sum of complex Gaussian functions, the approximate analytical expression of elegant Laguerre–Gaussian beams passing through a paraxial ABCD optical system with an annular aperture is derived. Meanwhile, the corresponding closed-forms for the unapertured, circular apertured or circular black screen cases are also given. The obtained results provide more convenience for studying their propagation and transformation than the usual way by using diffraction integral formula directly. Some numerical examples are given to illustrate the propagation properties of elegant Laguerre–Gaussian beams. 相似文献
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T. Asakura 《Optics Communications》1973,8(3):186-190
A formula was derived in paper 1 of the this series for investigating the Fresnel diffraction field of a slit aperture when the mutual coherence function of the illumination contains a quadratic phase term. That formula is applied to study the intensity distribution in the Fresnel diffraction field of a slit aperture illuminated by a quasi-monochromatic incoherent slit source. The phase term has a big effect on the features of Fresnel diffraction. 相似文献