Varga P, Török P
Department of Engineering Science, University of Oxford, UK.
J Opt Soc Am A Opt Image Sci Vis. 2000 Nov;17(11):2090-5. doi: 10.1364/josaa.17.002090.
We present results of numerical computations obtained from a theory described in Part 1 of our current investigations [J. Opt. Soc. Am. A 17, 2081 (2000)]. We show that a segment of a paraboloid mirror produces an intensity distribution identical to that of a high-aperture lens. It is shown that when the convergence angle of the paraboloid is increased beyond the pi/2 limit, the lateral resolution in the direction orthogonal to the incident polarization improves, whereas in the other direction the resolution worsens. Numerical results show that paraboloid mirrors of high convergence angle exhibit dispersion; that is, when the focal length is altered by a quarter of the wavelength the intensity in the focus changes from its maximum to its minimum value. A focal shift is observed that, in the case of a paraboloid of low convergence angle is identical to the Fresnel shift. However, a focal shift is also observed at large convergence angles.
我们展示了从我们当前研究的第1部分所描述的理论中获得的数值计算结果[《美国光学学会杂志A》17, 2081 (2000)]。我们表明，抛物面镜的一部分产生的强度分布与高孔径透镜的强度分布相同。结果表明，当抛物面的会聚角增加到超过π/2极限时，在与入射偏振正交的方向上的横向分辨率提高，而在另一个方向上分辨率变差。数值结果表明，高会聚角的抛物面镜表现出色散；也就是说，当焦距改变四分之一波长时，焦点处的强度从最大值变为最小值。观察到一个焦移，在低会聚角抛物面的情况下，该焦移与菲涅耳位移相同。然而，在大会聚角时也观察到了焦移。
