Author(s): Chen, G (Chen, Gang); Wu, ZX (Wu, Zhi-Xiang); Yu, AP (Yu, An-ping); Zhang, ZH (Zhang, Zhi-hai); Wen, ZQ (Wen, Zhong-quan); Zhang, K (Zhang, Kun); Dai, LR (Dai, Lu-ru); Jiang, SL (Jiang, Sen-lin); Li, YY (Li, Yu-yan); Chen, L (Chen, Li); Wang, CT (Wang, Chang-tao); Luo, XG (Luo, Xian-gang)
Source: SCIENTIFIC REPORTS Volume: 6 Article Number: 37776 DOI: 10.1038/srep37776 Published: NOV 23 2016
Abstract: The generation of a sub-diffraction optical hollow ring is of great interest in various applications, such as optical microscopy, optical tweezers, and nanolithography. Azimuthally polarized light is a good candidate for creating an optical hollow ring structure. Various of methods have been proposed theoretically for generation of sub-wavelength hollow ring by focusing azimuthally polarized light, but without experimental demonstrations, especially for sub-diffraction focusing. Super-oscillation is a promising approach for shaping sub-diffraction optical focusing. In this paper, a planar sub-diffraction diffractive lens is proposed, which has an ultra-long focal length of 600 lambda and small numerical aperture of 0.64. A sub-diffraction hollow ring is experimentally created by shaping an azimuthally polarized wave. The full-width-at-half-maximum of the hollow ring is 0.61 lambda, which is smaller than the lens diffraction limit 0.78 lambda, and the observed largest sidelobe intensity is only 10% of the peak intensity.
IDS Number: ED4HS
ISSN: 2045-2322