Angle-insensitive multilayer metacoating with dual-band selective emission for infrared camouflage and radiative cooling

The mid-infrared (MIR) spectral region, covering the atmospheric transmission windows (ATWs) of 3–5 μm (mid-wavelength infrared, MWIR) and 8–13 μm (long-wavelength infrared, LWIR), is critical for applications such as infrared camouflage and radiative cooling due to its low atmospheric absorption. Here, we present a high-efficiency, deep-subwavelength multilayer metacoating (MMC) designed for dual-band emission in the MWIR and LWIR ATWs. Through selective impedance matching, the quad-layer MMC achieves average emissivities of 0.79 in the MWIR and 0.83 in the LWIR ATWs, while suppressing emissivity to 0.33 in the non-ATW range of 5–8 μm. Experimental results confirm these findings, which arise from electromagnetic localization within the multilayer architecture and dissipation in lossy materials (Ti and Cr). Notably, the emitter exhibits angle-insensitive performance, maintaining emissivities of 0.65 (MWIR) and 0.72 (LWIR) at incidence angles up to 70°, and demonstrates effective LWIR camouflage against high-emissivity backgrounds. Theoretical analysis further reveals its potential for nighttime radiative cooling. This work advances scalable, low-cost metacoatings for dual-functional infrared technologies, addressing key challenges in military signature management, thermal regulation, and energy-efficient aerospace systems.