3D conical helix metamaterial–based isotropic broadband perfect light absorber

We present the design and fabrication of an isotropic broadband perfect light absorber in the near-infrared range using 3D metamaterials with a single resonator in the unit cell. The metamaterial resonator is comprised of a gold conical helix supported on a silicon pillar with back reflector realized on a silicon substrate. Simulations and experiments have demonstrated that the proposed absorber achieves a broad absorption band of more than 3 µm in the 1.5-4.5 µm wavelength range with an average absorbance of more than 90%. The numerical and experimental analyses show that the proposed device can provide both incident angle and polarization independent operations, which further widens the application prospects of our device.