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

Area of Science:

• Metamaterials and Nanophotonics
• Electromagnetic Wave Manipulation

Background:

• Electromagnetic scattering manipulation devices require high optical transmittance and broad operational bandwidth, especially for specialized applications like aircraft cockpits.
• Existing solutions often struggle to balance these concurrent performance demands.

Purpose of the Study:

• To propose and demonstrate two types of wideband absorptive meta-lattices with large reflection phase differences.
• To develop a novel diffusion metabsorber optimized for electromagnetic scattering reduction.

Main Methods:

• Utilized hybrid mechanisms of energy absorption and scattering modulation.
• Optimized meta-lattice spatial configuration using a global genetic algorithm.
• Fabricated and measured the diffusion metabsorber, comparing results with simulations.

Main Results:

• Achieved over 10-dB backward scattering reduction from 4.08 to 18 GHz (126.1% fractional bandwidth).
• Demonstrated polarization insensitivity and angular stability up to ±45° incidence angles.
• The diffusion metabsorber exhibits a low-profile (0.12 λL) and high optical transmittance (73.8% average).

Conclusions:

• The developed diffusion metabsorber effectively reduces electromagnetic scattering while maintaining high optical transmittance and mechanical flexibility.
• This technology holds significant potential for next-generation multifunctional optical windows in demanding environments.