Mielenz Klaus D
National Institute of Standards and Technology, Gaithersburg, MD 20899-8440.
J Res Natl Inst Stand Technol. 2004 Oct 1;109(5):457-64. doi: 10.6028/jres.109.033. Print 2004 Sep-Oct.
The classical theory of diffraction at plane apertures illuminated by normally incident light is modified so that diffraction on the source side of the screen is taken into consideration and the energy transport across the aperture plane is described by continuous functions. The modified field expressions involve the sums and differences of the Rayleigh-Sommerfeld diffraction integrals as descriptors of a bidirectional flow of energy in the near zones on either side of the aperture. The theory is valid for unpolarized fields, and a pragmatic argument is presented that it is applicable to metallic as well as black screens. The modified field expressions are used for numerical near-field computations of the diffraction profiles and transmission coefficients of circular apertures and slits. In the mid zone the modified theory is reduced to the Fresnel approximation, and here the latter may be used with confidence.
对平面孔径在垂直入射光照射下的经典衍射理论进行了修正，以便考虑屏幕源侧的衍射，并通过连续函数描述穿过孔径平面的能量传输。修正后的场表达式涉及瑞利 - 索末菲衍射积分的和与差，作为孔径两侧近区能量双向流动的描述符。该理论对非偏振场有效，并给出了一个实用的论点，即它适用于金属屏和黑屏。修正后的场表达式用于圆形孔径和狭缝的衍射轮廓及透射系数的数值近场计算。在中间区域，修正理论简化为菲涅耳近似，在此可以放心地使用菲涅耳近似。
