Open AccessFar-field sub-diffraction focusing lens based on binary amplitude-phase mask for linearly polarized light
Author(s) -
Gang Chen,
Kun Zhang,
Anping Yu,
Xianyou Wang,
Zhihai Zhang,
Yuyan Li,
Zhongquan Wen,
Chen Li,
Luru Dai,
Senling Jiang,
Feng Lin
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.011002
Subject(s) - optics , focal length , diffraction , lens (geology) , physics , cardinal point , amplitude , planar , phase (matter) , near and far field , wavelength , computer science , computer graphics (images) , quantum mechanics
Planar lenses are attractive photonic devices due to its minimized size and easy to integrate. However, planar lenses designed in traditional ways are restricted by the diffraction limit. They have difficulties in further reducing the focal spot size beyond the diffraction limit. Super-oscillation provides a possible way to solve the problem. However, lenses based on super-oscillation have always been affected by huge sidelobes, which resulted in limited field of view and difficulties in real applications. To address the problem, in the paper, a far-field sub-diffraction lens based on binary amplitude-phase mask was demonstrated under illumination of linearly polarized plane wave at wavelength 632.8 nm. The lens realized a long focal length of 148λ (94 µm), and the full width at half maximum of the focal line was 0.406λ, which was super-oscillatory. More important is that such a flat lens has small sidelobes and wide field of view. Within the measured range of [-132λ, + 120λ], the maximum sidelobe observed on the focal plane was less than 22% of the central peak. Such binary amplitude-phase planar lens can also be extended to long focal length far-field sub-diffraction focusing lens for other spectrum ranges.