A Broadband Achromatic Dielectric Planar Metalens in Mid-IR Range

Abstract

Metalens are planar lenses composed of the subwavelength arrays, which have unconventional and versatile functionalities to manipulate the light fields compared with the traditional lens. It is noted that the most metalens are designed in a monochromatic mode in the visible or mid-infrared range (mid-IR), however, the broadband range is needed in many practical applications, such as spectroscopy, sensing, and imaging. Here, we design and demonstrate a broadband achromatic dielectric metalens in the mid-IR range of 4 µm–5 µm for near diffraction-limited (1.0λ) focusing. The broadband achromatic propagation and focusing of the metalens are designed and simulated by constructing and optimizing the phase profile. The Pancharatnam-Berry (P-B) phases of all the elements contribute to the main phase increment of the whole phase profile of the metalens. The additional phase is constructed and optimized by using the random search algorithm to obtain the optimized size of all the elements. The focusing efficiency of the achromatic metalens is also optimized and averaged as the result of phase optimization within a wide band for the building elements, while it is lowered comparing with the regular metalens without broadband achromatic designing. Using this combined designing approach, various flat achromatic devices with the broadband metalens can find a new way for full-color detection and imaging.

Design and Analysis of the Dual-Band Far-Field Super-Resolution Metalens with Large Aperture

“…Over the last decade, metalenses have been proposed, possessing the revolutionary property to overcome the diffraction limit by capturing the high-level spatial frequency components of an object [ 1 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. Metalens composed of subwavelength metamaterials or metasurfaces can image and resolve the subwavelength details, thus achieving super-resolution imaging [ 5 , 6 , 7 , 8 , 9 ].…”

“…Metalens composed of subwavelength metamaterials or metasurfaces can image and resolve the subwavelength details, thus achieving super-resolution imaging [ 5 , 6 , 7 , 8 , 9 ]. By utilizing the integration of traditional optics and modern metasurface technology, metalens exhibits remarkable features, including free optical adjustment, tremendous design flexibility, precise control, smaller volume, and lighter weight [ 1 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. These attributes of metalens provide significant promising applications in the realms of optical fiber imaging, microscopic imaging, and photographic lenses [ 13 , 14 ].…”

“…By utilizing the integration of traditional optics and modern metasurface technology, metalens exhibits remarkable features, including free optical adjustment, tremendous design flexibility, precise control, smaller volume, and lighter weight [ 1 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. These attributes of metalens provide significant promising applications in the realms of optical fiber imaging, microscopic imaging, and photographic lenses [ 13 , 14 ]. The basic working principle of a metalens involves the use of subwavelength scatterers to tailor the characteristics of light that carry subwavelength information from the objects.…”

Fully polarized detection of mid-infrared broadband achromatic metalenses

“…Polarization information is also very important as it can reflect material composition, surface morphology, and other information of the substance [5][6] . However, infrared polarization imaging technology faces several challenges, one of the significant challenges is the chromatic aberration [7][8] . Therefore, the quality of infrared polarimetric imaging largely depends on the effectiveness and functionality of the polarization detector.…”