March 13, 2008 | N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, W. J. Padilla
This paper presents the design and experimental verification of a metamaterial absorber with near-unity absorbance. The structure consists of two metamaterial resonators that couple separately to electric and magnetic fields, enabling absorption of all incident radiation within a single unit cell layer. The absorber was fabricated and characterized, achieving a simulated full width at half maximum (FWHM) absorbance of 4%, making it ideal for imaging applications. Unlike conventional absorbers, this metamaterial consists solely of metallic elements, allowing the substrate to be optimized independently for other parameters.
The design involves two distinct metallic elements, with electric coupling provided by an electric ring resonator (ERR) and magnetic coupling achieved through a combination of the center wire of the electric resonator and a cut wire in a parallel plane. By manipulating the geometry of these elements, the magnetic response can be tuned independently of the electric response, enabling the decoupling of electric and magnetic properties.
Computer simulations using the finite-difference time domain (FDTD) method were performed to model the metamaterial absorber. The simulations showed a simulated absorbance of 96% at 11.5 GHz with a FWHM of 4%. Experimental measurements confirmed a peak absorbance of 88% at the same frequency. The absorber's performance was validated by measuring the complex S-parameters of a large planar array of pixels, demonstrating a high absorbance with minimal transmission and reflectance.
The study also investigated the effect of adding multiple metamaterial layers, showing that absorbance can approach unity with additional layers. The design's scalability allows for applications at various wavelengths, including mm-Wave and THz frequencies. The metamaterial's ability to achieve near-unity absorbance at room temperature makes it a promising candidate for bolometric applications, such as high-resolution imaging.
The research highlights the potential of metamaterials in creating narrow-band perfect absorbers, with applications in imaging, sensing, and other electromagnetic technologies. The design's simplicity and effectiveness in achieving high absorbance with minimal thickness make it a significant advancement in the field of metamaterials.This paper presents the design and experimental verification of a metamaterial absorber with near-unity absorbance. The structure consists of two metamaterial resonators that couple separately to electric and magnetic fields, enabling absorption of all incident radiation within a single unit cell layer. The absorber was fabricated and characterized, achieving a simulated full width at half maximum (FWHM) absorbance of 4%, making it ideal for imaging applications. Unlike conventional absorbers, this metamaterial consists solely of metallic elements, allowing the substrate to be optimized independently for other parameters.
The design involves two distinct metallic elements, with electric coupling provided by an electric ring resonator (ERR) and magnetic coupling achieved through a combination of the center wire of the electric resonator and a cut wire in a parallel plane. By manipulating the geometry of these elements, the magnetic response can be tuned independently of the electric response, enabling the decoupling of electric and magnetic properties.
Computer simulations using the finite-difference time domain (FDTD) method were performed to model the metamaterial absorber. The simulations showed a simulated absorbance of 96% at 11.5 GHz with a FWHM of 4%. Experimental measurements confirmed a peak absorbance of 88% at the same frequency. The absorber's performance was validated by measuring the complex S-parameters of a large planar array of pixels, demonstrating a high absorbance with minimal transmission and reflectance.
The study also investigated the effect of adding multiple metamaterial layers, showing that absorbance can approach unity with additional layers. The design's scalability allows for applications at various wavelengths, including mm-Wave and THz frequencies. The metamaterial's ability to achieve near-unity absorbance at room temperature makes it a promising candidate for bolometric applications, such as high-resolution imaging.
The research highlights the potential of metamaterials in creating narrow-band perfect absorbers, with applications in imaging, sensing, and other electromagnetic technologies. The design's simplicity and effectiveness in achieving high absorbance with minimal thickness make it a significant advancement in the field of metamaterials.