Infrared selective emitter for multiband camouflage with thermal management via femtosecond laser direct writing of grating patterns

The rapid progress of modern detection technologies has placed stringent demands on multiband camouflage systems, rendering single-band designs inadequate for operational use. Metamaterial emitters, due to tunable electromagnetic characteristics, are regarded as highly promising candidates for multiband concealment. Yet, the precise realization of micro/nanostructures remains a persistent fabrication challenge. In this work, a femtosecond laser direct writing (FsLDW) method is employed to produce patterned metamaterial emitters with high accuracy and structural flexibility. Periodic gratings are generated on ultrathin metallic films without thermal diffusion, which ensures uniformity and reproducibility. Using this strategy, a Cu/SiO 2 /Cu nanosandwiched selective emitter is fabricated. It achieves dual-band infrared camouflage with high reflectance (R 3-5 μm = 0.78 and R 8-14 μm = 0.83) and CO 2 laser camouflage via strong absorption at 10.6 μm. Moreover, enhanced emission in the non-atmospheric window (ε 5-8 μm = 0.74) facilitates effective thermal management, leading to lower surface temperature compared with low emissivity materials under identical conditions. These findings demonstrate that FsLDW provides a versatile and reliable approach for the development of multiband emitters integrating camouflage and thermal management functionalities.