新型人工电磁媒质对电磁波的调控及其应用. What s Metamaterial? Hot Research Topics. What s Metamaterial? Problem and Motivation. On Metamaterials 崔铁军 东南大学毫米波国家重点实验室

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1 What s Metamaterial? 新型人工电磁媒质对电磁波的调控及其应用 崔铁军 东南大学毫米波国家重点实验室 全国微波毫米波会议 2011 年 6 月 3 日 青岛 Metamaterial: 超材料 ; 新型人工电磁材料 ; 新型人工电磁媒质 ; 特异材料 ; 特异介质 ; What s Metamaterial? Hot Research Topics most materials Metamaterial>LHM One of the Ten Breakthroughs in Science in 2003 (Negative refraction) One of the Ten Breakthroughs in Science in 2006 (Invisibility cloaks) 微波 THz 光波 Metamaterials can provide fully electromagnetic characteristics Metamaterials can be highly anisotropic and inhomogeneous Problem and Motivation On Metamaterials Metamaterials Exciting topics A lot of new concepts, new findings Large amount of theoretical work and/or numerical simulations A number of experiments A few real applications Homogeneous metamaterials: Periodic structures Left-handed materials Zero-index medium / ENG / MNG Anisotropic metamaterials / chiral Plasmonic metamaterials Negative refraction / Super lens / Polarizer / Inhomogeneous metamaterials: Non-periodic structures More freedom to control electromagnetic waves

2 Homogeneous Metamaterials Tunneling Effect of Metamaterial Tunneling Effect of Metamaterial Liu, Cheng, Hand, Mock, Cui, Smith, PRL, 2008 Zero Index 2D Mapper Experiment Result at 8.04GHz: Control Sample Anisotropic Zero-Index Medium 3D AZI Antenna Superstrate ε 0 μ 0 z z hfss2 Q. Cheng, T. J. Cui, W. X. Jiang, J. Phys. D: Applied Physics, Yuan, Li, Cheng, Zhang, Cui, IEEE T-AP, 2011 (under review) 3D AZI Planar Antenna Substrate of Patch Antenna Artificial magneto-dielectric substrate: increase the permeability and decrease the permittivity, to get a better impedance matching, and to increase the bandwidth of the antenna. B. Zhou and T. J. Cui, IEEE AWPL, 2011 (accepted) X. M. Yang, T. J. Cui, et al., IEEE Transactions on Antennas and Propagation, Mar

3 Substrate of Patch Antenna Metamaterials Polarizers A schematic profile of the polarizer HFSS simulation results The -10dB bandwidth has been increased from 43 MHz to 84 MHz. J. Chin, M. Lu, T. J. Cui, Applied Physics Letters, 2008 Metamaterials Polarizers Broadband Metamaterial Polarizer linear polarization circular polarization linear polarization linear polarization J. Y. Chin, T. J. Cui, et al. Optics Express, 2009 Transmission Coefficient The transmission loss is less than -1dB, good axis ratio. Polarization Patterns Partial Focusing Inhomogeneous Metamaterials CELC Negative Energy Velocity Three approaches to design the inhomogeneous metamaterials: Geometrical optics: Gradient-index metamaterials Quasi-conformal mapping: all-dielectric metamaterials Transformation optics: anisotropic metamaterials Cheng, Liu, Cui, and Smith Physical Review B, 2008

4 Geometrical Optics 2D Flat Lens Antenna Metamaterial Flat Lens Antennas All optical paths from the source to the upper surface of the lens should have the same phase delay: Both electrical and magnetic responses Impedance matching Aperture: 12cm, 8 GHz Focal Point Gradient Index H. F. Ma, T. J. Cui, et al., Appl. Phys. Lett. 95, , D Broadband Flat Lens Antenna 3D Broadband Flat Lens Antenna Aperture Size H. Ma, T. J. Cui, Nature 9.6cm Communications (SI), 2010 Measured Gain 23 GHz 3D Large Flat Lens Antenna Compact-Range Measurement RCS Measurements Microwave Chamber (Expensive) Transmitter Square ring Drilling hole Plane Waves Receiver Target X. Y. Zou, H. F. Ma, and T. J. Cui, unpublished Compact-Range Measurement System

5 Free-Space Wave Bending Luneburg Lens Antenna From GO, the light rays travel in the circumferential directions. Then the linear form of Eikonal function is S = Aθ +C. And the refractive index for the bend structure is Broadband n = A/r. Z. L. Mei and T. J. Cui, Optical Express 17, p , 2009 Size: R=5cm H. F. Ma, T. J. Cui, et. al. Chin. Sci. Bulletin 55, p. 2066, 2010 EM Black Hole EM Black Hole Narimanov, et al., APL 95, (2009). GO-Fermat Principle Cheng, Cui, Jiang, Cai, New Journal of Physics, Vol.12, , 2010 Cheng, Cui, Jiang, Cai, New Journal of Physics, Vol.12, , 2010 Best of 2010 in NJP Quasi-Conformal Mapping Li and Pendry, Phys. Rev. Lett. 101, , Approximately isotropic All dielectric Liu, Ji, Mock, Chin, Cui*, Smith*, Science 323, 366 (2009)

6 Compact-Size Carpet Cloak 3D Broadband Cloak 6 times smaller Ma, Jiang, Cui, Opt. Exp. 17, p H. F. Ma, T. J. Cui, Nature Communications, June D Broadband Cloak 2010 年度中国科学十大进展 Vertical Polarization Horizontal Polarization Random Gradient Surface 3D Flattened Luneburg Lens Reflection Diffusion X.M. Yang, H. F. Ma, T. J. Cui, Optics Lett. 35, p. 808, Aperture: 10.8 cm; Height: 10.4 cm H. F. Ma and T. J. Cui, Nature Communications, Nov. 2010

7 3D Flattened Luneburg Lens Optical Transformation 1) High gain (22.7dBi); 2) Relatively low sidelobes; 3) Dual polarizations; 4) Large radiation angles (up to 50 o ); 5) Broad band (from 12 to 18 GHz). Invisible Cloak Elliptical Invisible Cloaks J. Phys. D: Appl. Phys., (2008) This work was selected as Research Highlights by Europhysics News Arbitrarily-Shaped Cloaks Cloak without Singularity When the becomes small, an approximate circular cloak is obtained. Physical Review E, 2008 highly cited paper Jiang and Cui, Applied Physics Letters, 2008

8 Arbitrarily-Shaped Concentrator Optical Illusion An illusion device consists of two distinct pieces of metamaterials, which are called as complementary medium and restoring medium. The concentrator can be easily used in amplifying plane waves. Lai, et al., PRL 102, , Require: LHM Radar-Illusion Devices In microwave, we propose a concept of radar illusion, which can make the EM image of a target gathered by the radar looks like another different target. Illusion is as important as cloaking, which can confuse the radar to make a wrong decision. Move an Object Virtually No LHM, No Singularities W. X. Jiang, T. J. Cui, et al., APL 96, , 2010 W. X. Jiang, T. J. Cui, et al., Optics Express, 2010 Shrinking an Arbitrarily-Shaped Object W. X. Jiang, T. J. Cui, et al., APL, 2011 Optical transformation: Inhomogeneous and anisotropic metamaterials Reduced material parameters under the TE polarization: a. Simulation: a dielectric target b. Simulation: virtual target c. Simulation: a dielectric target with illusion device d. Measurement

9 Convert Metallic Target to Dielectric Target W. X. Jiang and T. J. Cui, Optics Express, 2010 Convert Metallic Target to Dielectric Target Convert Metallic Target to Dielectric Target W. X. Jiang and T. J. Cui, Phys. Rev. E, Mar a. Measurement: a metallic target b. Measurement: a dielectric target c. Simulation: a metallic target with illusion device d. Measurement: a metallic target with illusion device Design of Metamaterials Measurement Facilities We have developed a rapid and accurate design tool for metamaterials; It took three months for the first cloak at Duke. Several minutes to design the cloak! Microwave Chamber 2D Mapping System

10 Thank you!