Flexible high-transparency diffusion metabsorber for optical windows with ultrawideband scattering reduction

For electromagnetic scattering manipulation devices applied to specialized scenarios such as aircraft cockpits, require the concurrent performance of both high optical transmittance and a broad operational bandwidth. With aid of the hybrid mechanisms of energy absorption and scattering modulation, we propose two types of wideband absorptive meta-lattices with large reflection phase differences. What we believe to be a novel diffusion metabsorber was prepared by optimizing the spatial configuration of these lattices using a global genetic algorithm. The agreement between simulation and measurement results demonstrates that the sample achieves over 10-dB backward scattering reduction from 4.08 to 18 GHz (corresponding to 126.1% fractional bandwidth) with polarization insensitivity and angular stability for incidence angles up to ±45°. Moreover, the believed to be novel diffusion metabsorber exhibits a low-profile configuration (0.12 λ_L), high optical transmittance (average transmittance of 73.8%), and mechanical flexibility, facilitating significant potential for next-generation multifunctional optical windows.