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Guo Z, Liu S, Li P, Wei B, Zhao J. Mathieu and Weber tightly autofocusing beams. OPTICS EXPRESS 2023; 31:17345-17353. [PMID: 37381471 DOI: 10.1364/oe.491445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 04/27/2023] [Indexed: 06/30/2023]
Abstract
We theoretically investigate the propagation dynamics of vectorial Mathieu and Weber tightly autofocusing beams, which are constructed based on nonparaxial Weber and Mathieu accelerating beams, respectively. They can automatically focus along the paraboloid and ellipsoid, and the focal fields represent the tightly focusing properties resembling that generated with a high NA lens. We demonstrate the influence of the beam parameters on the spot size and energy proportion of longitudinal component of the focal fields. It reveals that Mathieu tightly autofocusing beam supports a more superior focusing performance, of which the longitudinal field component with superoscillatory feature could be enhanced by decreasing the order and selecting the suitable interfocal separation of the beam. These results are expected to provide new insights for the autofocusing beams and the tight focusing of the vector beams.
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Li Y, Fan X, Huang Y, Guo X, Zhou L, Li P, Zhao J. Dielectric Metalens for Superoscillatory Focusing Based on High-Order Angular Bessel Function. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3485. [PMID: 36234611 PMCID: PMC9565310 DOI: 10.3390/nano12193485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
The phenomenon of optical superoscillation provides an unprecedented way to solve the problem of optical far-field label-free super-resolution imaging. Numerous optical devices that enable superoscillatory focusing were developed based on scalar and vector diffraction theories in the past several years. However, these reported devices are designed according to the half-wave zone method in spatial coordinates. In this paper, we propose a dielectric metalens for superoscillatory focusing based on the diffraction of angular Bessel functional phase modulated vector field, under the inspiration of the tightly autofocusing property of a radially polarized high-order Bessel beam. Based on this kind of metalens with a numerical aperture (NA) of 0.9, the linearly polarized light is converted into a radially polarized one and then focus into a superoscillating focal spot with the size of 0.32λ/NA. This angular spectrum modulation theory involved in this paper provides a different way of designing superoscillatory devices.
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Affiliation(s)
- Yu Li
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
- Xi’an Ming De Institute of Technology, Xi’an 710124, China
| | - Xinhao Fan
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
| | - Yunfeng Huang
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
| | - Xuyue Guo
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
| | - Liang Zhou
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
| | - Peng Li
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
| | - Jianlin Zhao
- MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
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