Engineering the dispersion of metamaterial surface for broadband infrared absorption.

We propose a broadband infrared absorber by engineering the frequency dispersion of metamaterial surface (metasurface) to mimic an ideal absorbing sheet. With a thin layer of structured nichrome, a polarization-independent absorber with absorption larger than 97% is numerically demonstrated over a larger than one octave bandwidth. It is shown that the bandwidth enhancement is related with the transformation of the Drude model of free electron gas in metal film to the Lorentz oscillator model of a bound electron in the structured metallic surface. We believe that the concept of dispersion engineering may provide helpful guidance for the design of a broadband absorber.

[1]  D. R. Chowdhury,et al.  Experimental demonstration of terahertz metamaterial absorbers with a broad and flat high absorption band. , 2011, Optics letters.

[2]  Willie J Padilla,et al.  Infrared spatial and frequency selective metamaterial with near-unity absorbance. , 2010, Physical review letters.

[3]  Sailing He,et al.  Omnidirectional, polarization-insensitive and broadband thin absorber in the terahertz regime , 2010 .

[4]  Gennady Shvets,et al.  Design of metamaterial surfaces with broadband absorbance. , 2011, Optics letters.

[5]  Nader Engheta,et al.  Circuits with Light at Nanoscales: Optical Nanocircuits Inspired by Metamaterials , 2007, Science.

[6]  Costas M. Soukoulis,et al.  Wide-angle perfect absorber/thermal emitter in the terahertz regime , 2008, 0807.2479.

[7]  Ata Khalid,et al.  Polarization insensitive, broadband terahertz metamaterial absorber. , 2011, Optics letters.

[8]  Willie J Padilla,et al.  Perfect metamaterial absorber. , 2008, Physical review letters.

[9]  Cheng Huang,et al.  Truncated spherical voids for nearly omnidirectional optical absorption. , 2011, Optics express.

[10]  Ekmel Ozbay,et al.  Optically thin composite resonant absorber at the near-infrared band: a polarization independent and spectrally broadband configuration. , 2011, Optics express.

[11]  T. Senior.  Approximate boundary conditions , 1981 .

[12]  Changtao Wang,et al.  Design principles for infrared wide-angle perfect absorber based on plasmonic structure. , 2011, Optics express.

[13]  D. Werner,et al.  An octave-bandwidth negligible-loss radiofrequency metamaterial. , 2011, Nature materials.

[14]  Erez Hasman,et al.  Metallic subwavelength structures for a broadband infrared absorption control. , 2007, Optics letters.

[15]  Willie J Padilla,et al.  Taming the blackbody with infrared metamaterials as selective thermal emitters. , 2011, Physical review letters.

[16]  David R. Smith,et al.  Controlling Electromagnetic Fields , 2006, Science.

[17]  Zhaowei Liu,et al.  Far-Field Optical Hyperlens Magnifying Sub-Diffraction-Limited Objects , 2007, Science.