Broadband generation of accelerating polygon beams with large curvature ratio and small focused spot using all-dielectric metasurfaces
Chen Lei,
Kanwal Saima,
Lu Yongzheng,
Zhang Dawei,
Chen Xu,
Chen Jian,
Wen Jing
Affiliations
Chen Lei
Engineering Research Center of Optical Instrument and Systems, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jun Gong Road, Shanghai, 200093, China
Kanwal Saima
Engineering Research Center of Optical Instrument and Systems, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jun Gong Road, Shanghai, 200093, China
Lu Yongzheng
Engineering Research Center of Optical Instrument and Systems, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jun Gong Road, Shanghai, 200093, China
Zhang Dawei
Engineering Research Center of Optical Instrument and Systems, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jun Gong Road, Shanghai, 200093, China
Chen Xu
Engineering Research Center of Optical Instrument and Systems, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jun Gong Road, Shanghai, 200093, China
Chen Jian
School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
Wen Jing
Engineering Research Center of Optical Instrument and Systems, Ministry of Education and Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, No. 516 Jun Gong Road, Shanghai, 200093, China
Self-accelerating polygon beams have drawn growing emphasis in optics owing to their exceptional characteristics of multiple self-accelerating channels and needle-like field distributions. Various approaches have been proposed to generate polygon beams, such as using spatial light modulators (SLMs) or plasmonic metasurfaces. However, SLMs impede the miniaturization of the optical system and both approaches are subject to low efficiencies and demand an extra physical lens with a long focal length for Fourier transform, which limits the quality and the diverse variability of polygon beams. In this article, we demonstrate the generation of high-quality accelerating polygon beams in broadband spectra of 500–850 nm by utilizing dielectric metasurfaces. These metasurfaces integrate the functionality of the Fourier transform lens to enable the resulting beams with a large curvature ratio for the self-accelerating channels and a relatively small size for the autofocus region. The curvature ratio of the beam at λ = 633 nm is 31 times higher than the previously reported plasmonic-based method. While the size of the focused spot is 2.35 µm, which is reduced by nearly 15 times. The proposed beam generator provides ample opportunities for applications such as particle micromanipulation, beam shaping, laser fabrication, and biomedical imaging.
