Hybrid Metamaterials Perfect Absorber and Sensitive Sensor in Optical Communication Band

The plasmonic metamaterial perfect absorber (MPA) is a recently developed branch of metamaterial which exhibits nearly unity absorption within certain frequency range.[1-6] The optically thin MPA possesses characteristic features of angular-independence, high Q-factor and strong field localization that have inspired a wide range of applications including electromagnetic wave absorption,[3, 7, 8] spatial[6] and spectral[5] modulation of light,[9] selective thermal emission,[9] thermal detecting[10] and refractive index sensing for gas[11] and liquid[12, 13] targets. In this work, we demonstrate a MPA working at terahertz (THz) regime and characterize it using an ultrafast THz time-domain spectroscopy (THz-TDS). Our study reveal an ultra-thin Fabry-Perot cavity mechanism compared to the impedance matching mechanism widely adopted in previous study [1-6]. Our results also shows higher-order resonances when the cavities length increases. These higher order modes exhibits much larger Q-factor that can benefit potential sensing and imaging applications. [1] C. M. Watts, X. L. Liu, and W. J. Padilla, "Metamaterial Electromagnetic Wave Absorbers," Advanced Materials, vol. 24, pp. 98-120, Jun 19 2012. [2] M. Hedayati, F. Faupel, and M. Elbahri, "Review of Plasmonic Nanocomposite Metamaterial Absorber," Materials, vol. 7, pp. 1221-1248, 2014. [3] N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, "Perfect metamaterial absorber," Physical Review Letters, vol. 100, p. 207402, May 23 2008. [4] H. R. Seren, G. R. Keiser, L. Cao, J. Zhang, A. C. Strikwerda, K. Fan, et al., "Optically Modulated Multiband Terahertz Perfect Absorber," Advanced Optical Materials, vol. 2, pp. 1221-1226, 2014. [5] D. Shrekenhamer, J. Montoya, S. Krishna, and W. J. Padilla, "Four-Color Metamaterial Absorber THz Spatial Light Modulator," Advanced Optical Materials, vol. 1, pp. 905-909, 2013. [6] S. Savo, D. Shrekenhamer, and W. J. Padilla, "Liquid Crystal Metamaterial Absorber Spatial Light Modulator for THz Applications," Advanced Optical Materials, vol. 2, pp. 275-279, 2014. [7] H. Tao, N. I. Landy, C. M. Bingham, X. Zhang, R. D. Averitt, and W. J. Padilla, "A metamaterial absorber for the terahertz regime: Design, fabrication and characterization," Optics Express, vol. 16, pp. 7181-7188, May 12 2008. [8] J. Hao, J. Wang, X. Liu, W. J. Padilla, L. Zhou, and M. Qiu, "High performance optical absorber based on a plasmonic metamaterial," Applied Physics Letters, vol. 96, p. 251104, 2010. [9] X. Liu, T. Tyler, T. Starr, A. F. Starr, N. M. Jokerst, and W. J. Padilla, "Taming the Blackbody with Infrared Metamaterials as Selective Thermal Emitters," Physical Review Letters, vol. 107, p. 045901, 07/18/ 2011. [10] T. Maier and H. Brückl, "Wavelength-tunable microbolometers with metamaterial absorbers," Optics Letters, vol. 34, pp. 3012-3014, 2009/10/01 2009. [11] A. Tittl, P. Mai, R. Taubert, D. Dregely, N. Liu, and H. Giessen, "Palladium-Based Plasmonic Perfect Absorber in the Visible Wavelength Range and Its Application to Hydrogen Sensing," Nano Letters, vol. 11, pp. 4366-4369, 2011/10/12 2011. [12] N. Liu, M. Mesch, T. Weiss, M. Hentschel, and H. Giessen, "Infrared Perfect Absorber and Its Application As Plasmonic Sensor," Nano Letters, vol. 10, pp. 2342-2348, Jul 2010. [13] G. H. Li, X. S. Chen, O. P. Li, C. X. Shao, Y. Jiang, L. J. Huang, et al., "A novel plasmonic resonance sensor based on an infrared perfect absorber," Journal of Physics D-Applied Physics, vol. 45, p. 205102, May 23 2012.

A metamaterial perfect absorber (MPA) using elliptical silver nanoparticles is proposed and investigated to provide 100% absorption for both transverse electric and transverse magnetic polarizations with a wide range of incident angles and polarization independence. Metamaterial absorbers with narrow absorption performance over a wide frequency range are significantly desired in sensing applications. Incident angle insensitivity and polarization angle independence are key features of MPAs. The output characteristics are examined using the three-dimensional finite difference time domain method. The effective medium theory and transmission line theory are applied to investigate the simulation results. Here, the 100% absorption occurs at resonance wavelength of λres = 2290 nm, and maximum sensitivity and figure of merit become 200 nm/RIU and 720 RIU-1, respectively. The results show that an absorption spectrum is insensitive to the incident angle of 0°-60°. The proposed device can be used as a high-performance biosensor and photodetector.

Wide-band polarization independent perfect metamaterial absorber based on concentric rings topology for solar cells application

An X-shaped triple split ring resonator-based metamaterial perfect absorber with quad-band incident and polarization angle insensitivity for C, X, and Ku band applications

Tunable multiple band THz perfect absorber with InSb metamaterial for enhanced sensing application

In this article, we presented our proposal for a metamaterial perfect absorber (MPA) operating in the near-infrared band. Our MPA comprised a trapezoidal silver layer, a substrate layer, and an intermediate alumina layer. The transmission characteristics of MPA were analyzed by the three-dimensional (3D) finite difference time domain method. The simulation results were analyzed by equivalent circuit theory. The results show that the MPA achieved 100% absorption of transverse magnetic (TM) polarization and transverse electric (TE) polarization with resonance wavelength λ = 1492.5 nm. By varying the length of the bottom side of the trapezoid, the MPA’s resonance wavelength could be effectively tuned, and the absorption was maintained at above 99%. With the incidence angle of 0°–55°, the absorption remains above 90% at TE polarization and above 80% at 55°–70°. The absorption at the TM polarization remains above 99% when the incident angle is 0°–70°. A wide angle of incidence and good absorption were achieved. The sensitivity (S) and figure of merit were 228 nm/refractive index unit and 1378 RIU−1, respectively. The proposed absorber with excellent absorption in the range of infrared spectra has a promising application potential in fields such as energy harvesting and infrared sensors.

In general metamaterial perfect absorber, the single meta-pattern makes the single absorption band. Therefore, the multi-absorption bands need the corresponding kinds of meta-patterns. Here, we introduce the triple-band metamaterial perfect absorber utilizing only single kind of pattern. We also demonstrate the absorption mechanism of the triple perfect absorption. The first and the second absorption bands were induced by the fundamental magnetic resonance of the major and the minor axes, respectively, of cut-wire bar. The third peak was caused by the third-harmonic magnetic resonance of the major axis. Additionally, the unexpected third band was formed, which was the overlapping of the third absorption peak with another absorption peak, which was made by pairs of antiparallel currents parallel or antiparallel to the incident electromagnetic wave.

A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al) metal-dielectric-metal system with top aluminium nano-disks was fabricated by laser-interference lithography and lift-off processing. The metamaterial absorber had peak resonant absorbance at 1090 nm and showed nonlinear absorption for 600ps laser pulses at 1064 nm wavelength. A nonlinear saturation of reflectance was measured to be dependent on the average laser power incident and not the peak laser intensity. The nonlinear behaviour is shown to arise from the heating due to the absorbed radiation and photo-thermal changes in the dielectric properties of aluminium. The metamaterial absorber is seen to be damage resistant at large laser intensities of 25 MW/cm2.

In this work, a triple-band perfect metamaterial absorber (MA) in the terahertz (THz) regime is demonstrated for different biochemical sensing applications. The metasurface’s unit cell is made up of a distinct metallic gear-shaped core with eight identical teeth and two concentric circular rings (CCRs) on the top layer. Finite-difference time-domain (FDTD) method-based software is utilized for modeling and numerical analysis, and a genetic algorithm (GA) is employed to optimize some geometric parameters of the absorber. The proposed MA shows almost 100% absorption in the frequency range from 0.5 to 4.5 THz. The MA becomes almost insensitive to polarization angle when the number of gear tooth has been increased. Resonance frequencies can be tweaked by adjusting the top layer’s geometric parameters while maintaining the absorption constant. The influence of different metals and forms in the top layer, such as solid and hollow circular metallic cores, on absorption spectra is also illustrated in this article. The modeled MA can detect glucose, ethanol, oils, and cancer cells (BCCs) by changing the resonance frequency and peak absorption of the spectra due to the variation in refractive index (RI) of the sample. When detecting ethanol, the absorber achieves a maximum sensitivity and figure of merit (FOM) of 56.67 THz/RIU and 358.7 RIU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> , respectively. In addition, the effects of incident angle of light and bending of MA on absorption are analyzed in this study. With this unique feasible design, structural tunability, and high sensitivity, the proposed absorber exhibits good promise in detecting biochemicals in the THz region.

We propose a design rule for broadband metamaterial absorbers and investigate their plasmonic properties under solar irradiation. The metamaterials consist of periodic arrays of titanium nitride (TiN) rings placed on an antireflective MgF2 dielectric film on a TiN bottom layer. We simulate the absorption of our metamaterials and find the dependence of the optical spectrum on structural parameters. From this, we propose a simple rule to design the nanostructures with an average spectral absorptivity greater than 95% over the solar spectrum from 200 to 3000 nm. Particularly, we introduce, for the first time, metamaterial perfect absorbers that can be designed using two-layer structures instead of higher-layer structures as conventional and sandwich designs. Our study would pave the way for great potential applications in the fields of solar energy harvesters and photo-to-thermal converters.

In this paper, we propose a frequency tunable metamaterial perfect absorber in the THz region based on graphene. The unit cell consists of a periodically patterned graphene cross-ring resonator and a gold film separated by a dielectric spacer. The simulation results demonstrate that the maximum value of absorption is 99.9% at 4.7 THz. By controlling the graphene conductivity, the frequency tunable characteristics can be achieved in this metamaterial absorber. When varying the diameter of the ring or the length of the cross, we find that resonance absorption frequency will significantly shifts. Moreover, the metamaterial absorber possesses the polarization-insensitive and a wide range of the incident angles up to 70° for both TE and TM polarization. Our absorber can be used in some practical applications due to its excellent absorption and simple structure.

Metamaterial based on a metal/insulator/metal (MIM) tri-layer structure provides an agile platform to realize high absorption efficiency for a variety of applications including semiconductor optoelectronic detectors. In this work, we use the finite time domain difference (FDTD) method and coupled mode theory (CMT) to numerically study metal/semiconductor/metal (MSM) structures and discuss their effective absorption for optoelectronic application. We compare MSM structures with a different top metal layer design and find that cross shaped absorber (CSA) and it's complementary cross shaped absorber (CCSA) exhibit different phase diagrams due to a distinctive dependence of radiation loss on geometrical parameters. Our results show that CSA (CCSA) structures are suitable for thinner (thicker) sandwiched semiconductor with a larger (smaller) imaginary part of its dielectric constant. The necessary condition to realize a maximum figure of merit (FOM) value for effective absorption is discussed in comparison with the perfect absorber condition. Our work may provide guidelines to design the general light-harvesting optoelectronic devices with high efficiencies based on metamaterial-semiconductor hybrid systems.

We report the simulation, fabrication, and experimental characterization of a single-layer broadband, polarization-insensitive and wide-angle near perfect metamaterial absorber (MA) in the microwave regime. The topology of the resonators is chosen in such a way that is capable of supporting simultaneously multiple plasmon resonances at adjacent frequencies, which lead to a broadband operation of the MA. Absorption larger than 80% at normal incidence covering a broad frequency range (between 7.4 GHz and 10.4 GHz) is demonstrated experimentally and through numerical simulations. Furthermore, the performance of the metamaterial absorber is kept constant up to an incident angle of 30°, for both TE and TM-polarizations. In addition, a hybrid model of the MA is proposed and implemented numerically in order to dynamically tune the absorption window. The hybrid MA is controlled by incorporating vanadium dioxide (VO2) temperature-driven metal-insulator phase transition material, which enables the transition from broadband (80% absorption and 3 GHz bandwidth) to narrowband (80% absorption and 0.7 GHz bandwidth) absorption window. Our proposed single-layer MA offers substantial advantages due to its low-cost and simplicity of fabrication. The results are very promising, suggesting a potential use of the MA in wide variety of applications including solar energy harvesting, biosensing, imaging, and stealth technology.

This paper presents a perfect metamaterial absorber (MA) based on rings and cross wires (RCWs) configuration in microwave frequency regime. Maxima absorption rate is at for simulation and at for experiment, in order. The proposed MA provides perfect absorption with angle of polarization independency. Consequently, suggested model enable myriad potential applications such as stealth and military technologies.

An isotropic Mie resonance-based metamaterial perfect absorber with near unity absorbance is experimentally and numerically demonstrated. The metamaterial is constructed with an array of dielectric cubes and a metallic ground plane. A good agreement between experimental and simulated result at X band absorption is achieved, the absorptivities are 97% and 98% at 9.96 GHz, separately. The absorption peak of the metamaterial perfect absorber is dependent on the permittivity, the size and the array pattern of the dielectric particles. The Mie resonance of dielectric particles provides a novel mechanism for creating the electric and magnetic resonances and offers a simpler route for the isotropic metamaterial perfect absorber with near unity absorbance.