10 Feb 2010 | Xianliang Liu1, Tatiana Starr2, Anthony Starr2, and Willie J. Padilla1*
A spatially and frequency selective metamaterial perfect absorber (MPA) has been demonstrated for the first time in the infrared regime. The device achieves 97% absorption at 6.0 microns, matching numerical simulations. The MPA consists of two sublattices: one for high absorption and another for near-zero absorption, enabling spatial and frequency-dependent absorption. This has potential applications in hyperspectral imaging and sub-sampling imaging.
Metamaterials, which manipulate electromagnetic waves through subwavelength structures, can achieve nearly any electromagnetic response. The MPA uses a cross-shaped resonator and a ground plane to generate resonant responses. By tuning the geometry of the resonator and the distance between elements, the electric and magnetic responses can be independently controlled. This allows the MPA to match the impedance of free space, minimizing reflectance at specific frequencies.
The optimized structure was simulated using CST Microwave Studio 2009, with parameters such as gold and Al2O3 layers. The experimental setup involved fabricating the MPA using E-beam deposition and ALD. The device was tested from 3 to 12 microns, showing 97% absorption at 6.0 microns. The results were compared with simulations, showing good agreement.
To demonstrate versatility, the MPA was combined with a low-absorption metamaterial to create a spatially selective absorber. This allowed for high contrast imaging. The device was also tested at 10 microns, showing near-zero absorption, similar to a perfect metal.
The MPA has potential applications in spatial light modulation, information coding, and single-pixel imaging. It can achieve a dynamic range of 40 dB, comparable to digital cameras. The device's solid-state nature and scalability suggest potential for sub-visible frequency applications. The study highlights the potential of metamaterials in achieving exotic applications, including hyperspectral imaging.A spatially and frequency selective metamaterial perfect absorber (MPA) has been demonstrated for the first time in the infrared regime. The device achieves 97% absorption at 6.0 microns, matching numerical simulations. The MPA consists of two sublattices: one for high absorption and another for near-zero absorption, enabling spatial and frequency-dependent absorption. This has potential applications in hyperspectral imaging and sub-sampling imaging.
Metamaterials, which manipulate electromagnetic waves through subwavelength structures, can achieve nearly any electromagnetic response. The MPA uses a cross-shaped resonator and a ground plane to generate resonant responses. By tuning the geometry of the resonator and the distance between elements, the electric and magnetic responses can be independently controlled. This allows the MPA to match the impedance of free space, minimizing reflectance at specific frequencies.
The optimized structure was simulated using CST Microwave Studio 2009, with parameters such as gold and Al2O3 layers. The experimental setup involved fabricating the MPA using E-beam deposition and ALD. The device was tested from 3 to 12 microns, showing 97% absorption at 6.0 microns. The results were compared with simulations, showing good agreement.
To demonstrate versatility, the MPA was combined with a low-absorption metamaterial to create a spatially selective absorber. This allowed for high contrast imaging. The device was also tested at 10 microns, showing near-zero absorption, similar to a perfect metal.
The MPA has potential applications in spatial light modulation, information coding, and single-pixel imaging. It can achieve a dynamic range of 40 dB, comparable to digital cameras. The device's solid-state nature and scalability suggest potential for sub-visible frequency applications. The study highlights the potential of metamaterials in achieving exotic applications, including hyperspectral imaging.