Ultrabroadband superoscillatory lens composed by plasmonic metasurfaces for subdiffraction light focusing

Abstract

Conventional optics is diffraction limited due to the cutoff of spatial frequency components, and evanescent waves allow subdiffraction optics at the cost of complex near‐field manipulation. Recently, optical superoscillatory phenomena were employed to realize superresolution lenses in the far field, but suffering from very narrow working wavelength band due to the fragility of the superoscillatory light field. Here, an ultrabroadband superoscillatory lens (UBSOL) is proposed and realized by utilizing the metasurface‐assisted law of refraction and reflection in arrayed nanorectangular apertures with variant orientations. The ultrabroadband feature mainly arises from the nearly dispersionless phase profile of transmitted light through the UBSOL for opposite circulation polarization with respect to the incident light. It is demonstrated in experiments that subdiffraction light focusing behavior holds well with nearly unchanged focal patterns for wavelengths spanning across visible and near‐infrared light. This method is believed to find promising applications in superresolution microscopes or telescopes, high‐density optical data storage, etc.

Creation of Sub-diffraction Longitudinally Polarized Spot by Focusing Radially Polarized Light with Binary Phase Lens

“…Although super-resolution can be achieved by near-field optics1718, super-oscillation provides a promising approach to realize far-field sub-diffraction focusing and imaging. Many planar diffractive lenses have been proposed for focusing and imaging beyond the diffraction limit192021222324252627. Although metasurfaces2628 have been reported for focusing purposes, their amplitude transmission rate is very low and they are difficult to be fabricated in visible wavelength range.…”

“…Many planar diffractive lenses have been proposed for focusing and imaging beyond the diffraction limit192021222324252627. Although metasurfaces2628 have been reported for focusing purposes, their amplitude transmission rate is very low and they are difficult to be fabricated in visible wavelength range. Recently, super-oscillation planar lenses based on quasi-continuous amplitude modulation2930 and a binary amplitude-phase mask31 have been demonstrated for sub-diffraction focusing of linearly polarized light.…”

Color display and encryption with a plasmonic polarizing metamirror

“…The collective oscillation of free electrons and photons at the interfaces of metal and dielectric materials are called surface plasmons [1,2], which have attracted tremendous attention and provided a platform to investigate a great deal of novel physical properties such as perfect absorption [3][4][5][6], subdiffraction focusing [7][8][9][10], and negative refraction [11][12][13]. Among the plentiful research subjects in the big family of plasmonic metamaterials, one of the intensively investigated topics in recent decades is the design of color filters [14][15][16][17][18][19][20][21][22][23][24][25], where a specific color is observed if the scattered light of a particular wavelength range comes into our eyes when an object is illuminated with white light.…”

Proximity correction and resolution enhancement of plasmonic lens lithography far beyond the near field diffraction limit

“…[16][17][18] More recently, various plasmonic lens lithography were proposed for the improvement of resolution, aspect prole and imaging contrast, by using smooth superlens, 19-21 metal reector cladding, [22][23][24] plasmonic cavity lens etc., 25,26 providing an efficient way for the fabrication of various nanostructures. [27][28][29] Plasmonic cavity lens even has achieved resolution up to a half-pitch of 22 nm in experiment.…”