Tamburini F, Anzolin G, Umbriaco G, Bianchini A, Barbieri C
Department of Astronomy, University of Padova, Vicolo dell' Osservatorio 2, Padova, Italy.
Phys Rev Lett. 2006 Oct 20;97(16):163903. doi: 10.1103/PhysRevLett.97.163903. Epub 2006 Oct 16.
We experimentally and numerically tested the separability of two independent equally luminous monochromatic and white light sources at the diffraction limit, using optical vortices (OV). The diffraction pattern of one of the two sources crosses a fork hologram on its center generating the Laguerre-Gaussian (LG) transform of an Airy disk. The second source, crossing the fork hologram in positions different from the optical center, generates nonsymmetric LG patterns. We formulated a criterion, based on the asymmetric intensity distribution of the superposed LG patterns so created, to resolve the two sources at angular distances much below the Rayleigh criterion. Analogous experiments in white light allow angular resolutions which are still one order of magnitude below the Rayleigh criterion. The use of OVs might offer new applications for stellar separation in future space experiments.
我们利用光学涡旋（OV），通过实验和数值方法测试了两个独立的、等光强的单色光源和白光光源在衍射极限下的可分离性。两个光源之一的衍射图案在其中心穿过一个叉形全息图，生成艾里斑的拉盖尔 - 高斯（LG）变换。第二个光源在与光心不同的位置穿过叉形全息图，产生非对称的LG图案。我们基于如此创建的叠加LG图案的不对称强度分布制定了一个标准，以在远低于瑞利判据的角距离下分辨这两个光源。白光下的类似实验允许的角分辨率仍比瑞利判据低一个数量级。光学涡旋的应用可能会在未来的太空实验中为恒星分离提供新的应用。
