All-dielectric spectral selective emitter for infrared-microwave compatible stealth

Abstract

The advancement of infrared detection technology has imposed increasingly stringent requirements on the infrared radiation regulation materials. Spectral selective emitters can effectively mitigate infrared signals within the detected bands, while simultaneously leveraging undetected band for efficient radiative cooling, thereby enhancing the infrared stealth effectiveness. Herein, we design an all-dielectric selective emitter consisting of only five layers by incorporating the SiO2 reststrahlen layer with a Ge/MgF2 photonic multilayers. We quantified the infrared stealth performance of the selective emitter that the emissivity in the undetected band (5−8 μm) is 0.81 and the emissivity values in detected bands are 0.20 (3−5 μm) and 0.17 (8−13 μm), respectively. The simulation results demonstrate that the selective emitter exhibits superior radiative cooling performance and infrared stealth capabilities, as evidenced by significantly lower physical temperature and radiation intensity compared to traditional broadband low emissivity emitters. Furthermore, the all-dielectric structure ensures nearly perfect microwave transmissivity for selective emitters. When combined with microwave absorbers, they exhibit a remarkable microwave absorptivity exceeding 0.9 within the 8−18 GHz range, effectively achieving infrared-microwave compatible stealth. The all-dielectric emitter presents a novel structure for spectral selective infrared radiation control materials, featuring reduced layer complexity and the absence of metallic materials, thereby enhancing its potential for temperature resistance. This work holds significant implications for advancing selective emitters in high-temperature infrared-microwave compatible stealth applications.