Thermochromism Frequency-Selective Emitter for Infrared Stealth Application
Yuechao Zhao, Fei Fang
Abstract
A thermochromism frequency-selective emitter (TFSE) capable of both emissivity modulation and radiative cooling is presented. The emitter integrates a metallic resonating component and the phase change material of vanadium dioxide (VO2). In the atmospheric windows of 3–5 and 8–14 μm wave bands, the emissivity of the TFSE varies from 0.41 to 0.11 as the phase transition of VO2 from the insulating to metallic phase takes place. In the atmospheric absorption band of 5–8 μm, the emitter can actively dissipate heat. Besides, the TFSE hardly shows any effect of incident angles on infrared emissivity. The resonant absorption behavior is analyzed via electromagnetic field distribution and further verified by an inductance–capacitance (LC) model. Based on the relationship between the resonance wavelength and metal disk diameter, the TFSE with multiple absorption peaks in the atmospheric absorption band is designed, which shows remarkable heat dissipation potential. The TFSE holds great potential in applications of adaptive infrared stealth technology and active management of radiative thermal energy.