The modulation of thermal radiation in the infrared region is a highly anticipated method to achieve infrared sensing and camouflage. Here, a multiband metamaterial emitter based on the Al / SiO 2 / Al nanosandwich structure is proposed to provide new ideas for effective infrared and laser-compatible camouflage. By virtue of the intrinsic absorption and magnetic resonance property of lossy materials, the thermal radiation in the infrared region can be rationally modulated. The fabricated samples generally present low emissivity ( ε 3 – 5   μm = 0.21 , ε 8 – 14   μm = 0.19 ) in the atmospheric windows to evade infrared detection as well as high emissivity ( ε 5 – 8   μm = 0.43 ) in the undetected band for energy dissipation. Additionally, the laser camouflage is also realized by introducing a strong absorption at 10.6 μm through the nonlocalized plasmon resonance of the SiO 2 layer. Moreover, the fabricated emitter shows promising prospects in thermal management due to the good radiative cooling property that is comparable to the metallic Al material. This work demonstrates a multiband emitter based on the metasurface structure with compatible infrared-laser camouflage as well as radiative cooling properties, which is expected to pave new routes for the design of thermal radiation devices.

Due to its unique electronic and optical properties, graphene has been used to design tunable optical absorbers. In this paper, we propose a plasmonic absorber consisting of non-concentric graphene nanodisk arrays, which is designed to operate in the mid-infrared spectral range and is capable of achieving nearly perfect absorption. Two perfect absorption peaks are produced due to the impedance of the structure, which matches that of the free space. The influences of the thicknesses of the dielectric layer, the size of graphene nanodisk, and the incident conditions on the absorption are studied. Moreover, the absorption intensity can be independently tuned by varying the Fermi levels of two graphene nanodisks. Furthermore, the polarization-independent absorbance of the absorber exceeds 95% under oblique incidence, and remains very high over a wide angle. This proposed absorber has potential applications in optical detectors, tunable sensors, and band-pass filters.

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An active plasmonic device is designed to support multiple perfect absorption peaks using the highly confined graphene surface plasmons excited by silicon-based diffractive gratings. The physical origination corresponding to different absorption peaks is analyzed and the principle of impedance matching is used to explain perfect absorption. We show that the absorption spectrum is effectively controllable over a wide wavelength range by changing the Fermi levels, relaxation time of the graphene and geometric parameters of the device. This study could provide some possibility facilitating the design of next generation optical and photoelectronic structure by combining graphene and dielectric grating.