Broadband mid-infrared perfect absorber using fractal Gosper curve

TL;DR

This paper introduces an ultra-broadband mid-infrared metamaterial absorber using a fractal Gosper curve, achieving high absorption across a wide wavelength range with polarization and incident angle insensitivity.

Contribution

The study presents a novel fractal geometry-based design for broadband metamaterial perfect absorbers, overcoming narrow bandwidth limitations of surface plasmon resonances.

Findings

Achieves an average absorptivity of 95.78% from 2.64 to 9.79 μm

Insensitive to polarization and incident angle variations

Utilizes multiple electric resonances supported by fractal segments

Abstract

Designing broadband metamaterial perfect absorbers is challenging due to the intrinsically narrow bandwidth of surface plasmon resonances. Here, the paper reports an ultra-broadband metamaterial absorber by using space filling Gosper curve. The optimized result shows an average absorptivity of 95.78% from 2.64 to 9.79 {\mu}m across the entire mid-infrared region. Meanwhile, the absorber shows insensitivity to the polarization angle and the incident angle of the incident light. The underlying physical principles, used in our broadband absorber, involve a fractal geometry with multiple scales and a dissipative plasmonic crystal. The broadband perfect absorption can be attributed to multiple electric resonances at different wavelengths supported by a few segments in the defined Gosper curve.