Switchable polarization-multiplexed super-oscillatory metasurfaces for achromatic sub-diffraction focusing

Abstract

Super-oscillation phenomenon has attracted considerable interests due to its great ability of far-field super-resolution imaging. However, most super-oscillatory lenses were limited by chromatic aberration and single functionality, hence deeply restricting the flexibility of the super-oscillatory devices in practical applications. Here, an achromatic polarization-multiplexed super-oscillatory metasurface has been proposed to realize flexible light field modulations at different colors, i.e. 473 nm (blue), 532 nm (green), and 632.8 nm (red). The super-oscillatory metasurface can achieve achromatic diffraction-limited focusing under x-polarized light illumination and achromatic sub-diffraction focusing under y-polarized light illumination. Furthermore, it can also realize multi-wavelength super-oscillatory achromatic focusing with different super-resolution abilities. The proposed method could simplify the super-resolution optical imaging system and is expected to have widespread applications in color imaging, microscopy, and machine vision.

Transmission–Reflection‐Integrated Quadratic Phase Metasurface for Multifunctional Electromagnetic Manipulation in Full Space

“…So far, some multiplexing approaches, including polarization, frequency, and orbital angular momentum (OAM) multiplexing, have been employed to integrate multifunctional EM functionalities into one metasurface. [17][18][19] For instance, anisotropic plasmonic nanostructures were reported to simultaneously control the intensity and phase by changing incidence polarization. [20] In ref.…”

Computational hyperspectral devices based on quasi-random metasurface supercells

“…Metasurfaces are ultrathin two-dimensional materials with an exotic ability to flexibly manipulate the amplitude, phase, and polarization of light. [16][17][18][19] They have been applied in the fields of lithography, [20][21][22] achromatic metalens, [23][24][25][26] optical waveguides, 27,28 extraordinary Young's interference, 29,30 and vector light field. [31][32][33] Researchers have been exploring the use of lightweight spectral devices based on metasurfaces as a replacement for bulky traditional spectrometers.…”

Inverse design of sub-diffraction focusing metalens by adjoint-based topology optimization

“…One of the forward design methods is optimization-free algorithms [31] proposed by Huang kun et al It has clear physical correspondence but some deficiencies, such as too much prior knowledge, few optimization variables, and parameter precision may not be appropriate for all sub-diffraction problems. Another method relies on optimization algorithms such as particle swarm optimization (PSO) and genetic algorithm, but it is often accompanied by a unit-cell-based method [19,24,32], which is passive and time-consuming. Similarly, there are two ways in inverse design.…”