Broadband absorber with periodically sinusoidally-patterned graphene layer in terahertz range.

We demonstrate that a broadband terahertz absorber with near-unity absorption can be realized using a net-shaped periodically sinusoidally-patterned graphene sheet, placed on a dielectric spacer supported on a metallic reflecting plate. Because of the gradient width modulation of the unit graphene sheet, continuous plasmon resonances can be excited, and therefore broadband terahertz absorption can be achieved. The results show that the absorber's normalized bandwidth of 90% terahertz absorbance is over 65% under normal incidence for both TE and TM polarizations when the graphene chemical potential is set as 0.7 eV. And the broadband absorption is insensitive to the incident angles and the polarizations. The peak absorbance remains more than 70% over a wide range of the incident angles up to 60° for both polarizations. Furthermore, this absorber also has the advantage of flexible tunability via electrostatic doping of graphene sheet, which peak absorbance can be continuously tuned from 14% to 100% by controlling the chemical potential from 0 eV to 0.8 eV. The design scheme is scalable to develop various graphene-based tunable broadband absorbers at other terahertz, infrared, and visible frequencies, which may have promising applications in sensing, detecting, and optoelectronic devices.

[1]  F. J. Garcia-Vidal,et al.  Surface plasmon enhanced absorption and suppressed transmission in periodic arrays of graphene ribbons , 2011, 1201.0191.

[2]  Mohammad P. Hokmabadi,et al.  Terahertz metamaterials perfect absorbers for sensing and imaging , 2013, Photonics West - Biomedical Optics.

[3]  Sailing He,et al.  Broadband THz Absorbers With Graphene-Based Anisotropic Metamaterial Films , 2013, IEEE Transactions on Terahertz Science and Technology.

[4]  M. Choe,et al.  Large-scale patterned multi-layer graphene films as transparent conducting electrodes for GaN light-emitting diodes , 2010, Nanotechnology.

[5]  S. Fan,et al.  Graphene surface plasmons at the near-infrared optical regime , 2014, Scientific Reports.

[6]  G. Hanson,et al.  Dyadic Green's Functions for an Anisotropic, Non-Local Model of Biased Graphene , 2008, IEEE Transactions on Antennas and Propagation.

[7]  J. S. Gomez-Diaz,et al.  Graphene-based plasmonic switches at near infrared frequencies. , 2013, Optics express.

[8]  Qin Shiqiao,et al.  Broadband single-layered graphene absorber using periodic arrays of graphene ribbons with gradient width , 2014 .

[9]  B. Wang,et al.  Plasmonic absorption enhancement in periodic cross-shaped graphene arrays , 2015, 2015 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP).

[10]  Harald Schneider,et al.  Ultrafast graphene-based broadband THz detector , 2013 .

[11]  G. Hanson.  Dyadic Green's functions and guided surface waves for a surface conductivity model of graphene , 2007, cond-mat/0701205.

[12]  W. Withayachumnankul,et al.  Photonic crystal traps THz waves , 2014, Nature Photonics.

[13]  R. J. Bell,et al.  Optical properties of the metals Al, Co, Cu, Au, Fe, Pb, Ni, Pd, Pt, Ag, Ti, and W in the infrared and far infrared. , 1983, Applied optics.

[14]  Shitao Yan,et al.  Tunable terahertz absorption in graphene-based metamaterial , 2015 .

[15]  A. Lavrinenko,et al.  Graphene metamaterials based tunable terahertz absorber: effective surface conductivity approach. , 2013, Optics express.

[16]  James P. Grant,et al.  Terahertz Metamaterial Absorbers Implemented in CMOS Technology for Imaging Applications: Scaling to Large Format Focal Plane Arrays , 2017, IEEE Journal of Selected Topics in Quantum Electronics.

[17]  Ashkan Vakil,et al.  Transformation optics using graphene: One-atom-thick optical devices based on graphene , 2012 .

[18]  Michal Lipson,et al.  Graphene electro-optic modulator with 30 GHz bandwidth , 2015, Nature Photonics.

[19]  Leila Yousefi,et al.  Tunable THz perfect absorber using graphene-based metamaterials , 2015 .

[20]  Liang Wang,et al.  Fast Patterned Graphene Ribbons Via Soft–lithography☆ , 2016 .

[21]  Kwang S. Kim,et al.  Large-scale pattern growth of graphene films for stretchable transparent electrodes , 2009, Nature.

[22]  X. M. Liu,et al.  Graphene-clad microfibre saturable absorber for ultrafast fibre lasers , 2016, Scientific Reports.

[23]  Sukosin Thongrattanasiri,et al.  Complete optical absorption in periodically patterned graphene. , 2012, Physical review letters.

[24]  A. Alú,et al.  Terahertz Metamaterial Devices Based on Graphene Nanostructures , 2013, IEEE Transactions on Terahertz Science and Technology.

[25]  Zhifeng Ren,et al.  Metallic nanostructures for light trapping in energy-harvesting devices , 2014, Light: Science & Applications.

[26]  J. Perruisseau-Carrier,et al.  Plane wave excitation-detection of non-resonant plasmons along finite-width graphene strips. , 2013, Optics express.

[27]  V. Gusynin,et al.  Magneto-optical conductivity in graphene , 2007, 0705.3783.

[28]  N. Peres,et al.  Fine Structure Constant Defines Visual Transparency of Graphene , 2008, Science.

[29]  Ken Liu,et al.  Electrically controlling the polarizing direction of a graphene polarizer , 2014 .

[30]  Bo O. Zhu,et al.  Graphene based tunable metamaterial absorber and polarization modulation in terahertz frequency. , 2014, Optics express.

[31]  Swapan K. Pati,et al.  Novel properties of graphene nanoribbons: a review , 2010 .

[32]  Jie Ji,et al.  Dual-band tunable perfect metamaterial absorber in the THz range. , 2016, Optics express.

[33]  Xiang-Kun Kong,et al.  A wide-angle broadband absorber in graphene-based hyperbolic metamaterials , 2014 .

[34]  Gunuk Wang,et al.  Enhanced Charge Injection in Pentacene Field‐Effect Transistors with Graphene Electrodes , 2011, Advanced materials.

[35]  Gamani Karunasiri,et al.  Bi-material terahertz sensors using metamaterial structures. , 2013, Optics express.

[36]  Zongfu Yu,et al.  A multiple-resonator approach for broadband light absorption in a single layer of nanostructured graphene. , 2015, Optics express.

[37]  Brent M. Polishak,et al.  Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials , 2011 .

[38]  F. Lederer,et al.  A perfect absorber made of a graphene micro-ribbon metamaterial. , 2012, Optics express.

[39]  Q. Lu,et al.  Toward integrated electrically controllable directional coupling based on dielectric loaded graphene plasmonic waveguide. , 2015, Optics letters.

[40]  Xiewen Wen,et al.  Broadband light absorption in graphene ribbons by canceling strong coupling at subwavelength scale. , 2016, Optics express.

[41]  Wei Li,et al.  Ultrafast all-optical graphene modulator. , 2014, Nano letters.

[42]  Jianjun Liu,et al.  Absorber: a novel terahertz sensor in the application of substance identification , 2016 .

[43]  H. Bağcı,et al.  An ultra-broadband multilayered graphene absorber. , 2013, Optics express.

[44]  Lin Chen,et al.  Graphene-based tunable broadband hyperlens for far-field subdiffraction imaging at mid-infrared frequencies. , 2013, Optics express.

[45]  W. Liu,et al.  Towards photodetection with high efficiency and tunable spectral selectivity: graphene plasmonics for light trapping and absorption engineering. , 2015, Nanoscale.

[46]  Peter Nordlander,et al.  Graphene-antenna sandwich photodetector. , 2012, Nano letters.