Ultra-broadband absorber designed with the aid of the particle swarm optimization algorithm

This study proposes an ultrabroadband absorber composed of nanocolumns across the ultraviolet-near-infrared spectrum. Calculations indicate that the absorber maintains a consistent absorptivity exceeding 90% throughout the 350–1950nm band, with an average absorptivity of 96%. Leveraging the distinctive response of unit cells of varying sizes to different wavelengths, multiple unit cells are combined into a supercell and adjacent absorption peaks are consolidated to achieve broadband absorption. Particle swarm optimization is employed for a reverse design, which facilitates the determination of the optimal parameters for the unit cells. The results suggest the feasibility of designing absorbers featuring high efficiency, polarization insensitiveness, and wide angles. This study presents a promising method featuring high flexibility and low computational consumption for absorber design.