All-metal frequency-selective absorber/emitter for laser stealth and infrared stealth

Abstract

In this paper, an all-metal nanostructure is designed with a large frequency ratio (∼6) and a large bandwidth ratio (∼32), and consists of period slit-box cavities and nanodisk clusters. It is a nearly perfect absorber at 1.064 μm to achieve laser stealth, a frequency-selective emitter with low emissivity in wavelength ranges 3-5 and 8-14 μm to achieve infrared stealth, and also an emitter with near unity emissivity at 2.709 μm and 6.107 μm to compensate for the decrease of radiation heat transfer owing to the low emissivity. The absorption/emission peaks are all the Lorentzian shape, and the bandwidths, defined as full width at half-maximum, are 35, 408, and 1124 nm at 1.064, 2.709, and 6.107 μm, respectively. The electric and magnetic field distribution shows that the slit behaves like a capacitor, the box behaves like an inductance, and the nanodisk clusters can excite electric dipole resonance. Considering the solar irradiation, the nanostructure maintains middle-wavelength infrared signal reduction rates greater than 80% from 450 to 1000 K, and long-wavelength infrared signal reduction rates greater than 90% from room temperature to 1000 K. The laser and infrared stealth performances of our nanostructure at 473 K are also studied with different incident angles and polarization angles.

Scalable and High-Throughput Top-Down Manufacturing of Optical Metasurfaces

“…Compared to other previous studies, the advanced fabrication process opens new way for mass production of metasurface-based waveplates and CMOS-compatible flat optics. Metasurface-based perfect absorbers are also required to be realized over large areas for practical applications such as photovoltaic devices, energy-harvesting devices, and stealth technology [ 72 , 73 ]. The dual-band perfect absorber showed absorption efficiencies of 45% and 75% at 18.1 and 26.8 THz, respectively ( Figure 2 g) [ 74 ].…”

A Multilayer Film Based Selective Thermal Emitter for Infrared Stealth Technology

“…Materials with radiation wavelength selectivity have received considerable attention from researchers due to their potential applications, especially in thermophotovoltaic (TPV) systems, radiative cooling, infrared stealth, etc. A TPV system is an electrical generator that converts heat radiation energy into electrical energy with high efficiency.…”

“…Contrary to radiative coolers, infrared stealth technology, which is widely utilized by aircrafts, tanks, ships, missiles, and satellites to make them “invisible” to infrared detection equipment, demands the suppression of thermal radiation energy in the two atmospheric windows (3–5 and 8–14 µm) representing the main transmission channels for electromagnetic waves in the atmosphere . The thermal radiation energy, defined as the radiance exitance P , radiated from an object can be suppressed by both reduction of the emissivity and the real temperature, according to the Steven–Boltzmann Law, P = εσT 4 , where σ is the Steven–Boltzmann constant and ε and T are the emissivity and absolute temperature of the object, respectively.…”

Artificial Surfaces and Media for Electromagnetic Absorption and Interference Shielding

“…Electromagnetic absorbers have important applications in a plethora of applications, including but not limited to electromagnetic interferences and electromagnetic compatibility [1][2][3][4][5], stealth [6][7][8][9], camouflage [10], shielding [11][12][13], energy harvesting [14,15], as well as antenna and optical measurements [2,[16][17][18]. Recently, the scientific interest has focused on EMC and EMI shielding that studies how to suppress noise or interference in various electronic appliances and radiative damage to humans caused by unintended EM signals.…”