Spatial and Frequency Selective Plasmonic Metasurface for Long Wavelength Infrared Spectral Region

Abstract

The development of novel approaches that control absorption and emission operating in long wavelength infrared (LWIR) spectral region is of fundamental importance for many applications, such as, remote temperature sensing, environmental monitoring, thermal imaging, radiation cooling and industrial facility inspections. A high performance plasmonic metasurface-based absorber for the LWIR spectral region is presented. In our design, a pyroelectric thin film, poly(vinylidene fluoridetrifluoroethylene) (P(VDF-TrFE)) copolymer, is introduced as spacer, that offers the device not only with multiple selective high absorption bands but also promising potential for application in optoelectronics. By employing a scattering-type near-field optical microscopy (s-SNOM), both the near-field amplitude and phase optical responses of the absorber are investigated at resonant wavelength, thereby providing direct experimental evidence to verify the nature of the absorption effect. To further demonstrate the versatility of our design, a particular metasurface patterned by the building blocks of the plasmonic absorber is fabricated and characterized. Two-dimensional hyperspectral images show that such a patterned structure exhibits both frequency and spatially selective absorption.

Hierarchical Metamaterials for Multispectral Camouflage of Infrared and Microwaves

“…Metamaterial perfect absorbers (MPAs) possess exotic EM radiative properties, which may open up potential applications in the signature control of military targets to evade detection, such as in tanks, aircrafts, and ships by acting as radar absorbers, selective emitters, and infrared (IR) camouflage . To achieve perfect absorption at a specific wavelength, metal–dielectric–metal (MDM) structured metamaterials harness the inevitable loss that is present in all real‐life applications. In principle, perfect absorption is achieved in an MDM structure by: 1) obtaining zero reflection by matching the impedance; 2) obtaining zero transmission by using the metal ground, and 3) obtaining perfect absorption by maximizing the losses.…”

Large‐Area, Broadband, Wide‐Angle Plasmonic Metasurface Absorber for Midwavelength Infrared Atmospheric Transparency Window

“…Previously, various optical engineering structures, such as photonic crystals, optical cavities, and metallic gratings, have been widely investigated to enhance electromagnetic wave absorption. Plasmonic metasurfaces constructed by artificially engineered subwavelength meta‐atoms have also been suggested to function as super absorbers . In particular, after the first metasurface‐type absorber demonstrated in microwave frequency region with single band absorption, much effort has so far been done to address the narrowband limitation and develop broadband absorbers for midinfrared.…”

Wide gamut, angle-insensitive structural colors based on deep-subwavelength bilayer media

“…In contrast to traditional colors generated from chemical dyes or pigments by the selective absorption and reflection of specific wavelengths of light, structural colors that arise from the interaction between light and nanostructures of objects rely strongly on the arrangement and shape of the nanostructures rather than their chemical properties, and have attracted great interest in recent decades due to their advantages of lower toxicity, superior stability, and higher anti-fading capacity [5][6][7]. During the past years, many types of optical engineering structures, such as, photonic crystals [8][9][10][11][12], metallic gratings [13], optical antennas [14,15], plasmonic metamaterials, and metasurfaces [16][17][18][19][20][21][22][23][24][25], have been introduced to generate structural colors. While a wide gamut of color space can be covered based on such artificially engineered nanostructures, the realization of such nanostructures generally requires high precision micro-nano-fabrication techniques such as, electron-beam lithography [20,21], nanoimprint lithography [22], focused ion beam milling [23], and direct laser writing [24], etc.…”