# 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.

## Key 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.

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Source: https://tomesphere.com/paper/1908.06635