1. Institute of Electromagnetics and Acoustics and Department of Electronic Science, Xiamen University, Xiamen 361005, China 2. Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, China
We present a series of invisibility concentrators with simplified material parameters beyond transformation optics. One of them can achieve the perfect invisible effect at frequencies of Fabry–Pérot resonances, while others have very small scattering. The required materials are feasible in practice. Analytical calculations and numerical simulations confirm the functionalities of these devices.
H. Chen and C. Chan, Transformation media that rotate electromagnetic fields, Appl. Phys. Lett. 90(24), 241105 (2007) https://doi.org/10.1063/1.2748302
C. Chu, X. Zhai, C. J. Lee, P. H. Wang, Y. Duan, D. P. Tsai, B. Zhang, and Y. Luo, Phase-preserved macroscopic visible-light carpet cloaking beyond two dimensions, Laser Photonics Rev. 9(4), 399 (2015) https://doi.org/10.1002/lpor.201500020
9
Y. Lai, H. Chen, Z. Q. Zhang, and C. T. Chan, Complementary media invisibility cloak that cloaks objects at a distance outside the cloaking shell, Phys. Rev. Lett. 102(9), 093901 (2009) https://doi.org/10.1103/PhysRevLett.102.093901
10
Y. Lai, J. Ng, H. Chen, D. Z. Han, J. J. Xiao, Z.Q. Zhang, and C. T. Chan, Illusion optics: The optical transformation of an object into another object, Phys. Rev. Lett. 102(25), 253902 (2009) https://doi.org/10.1103/PhysRevLett.102.253902
11
T. Y. Huang, H. C. Lee, I. W. Un, and T. J. Yen, An innovative cloak enables arbitrary multi-objects hidden with visions and movements, Appl. Phys. Lett. 101, 151901 (2012) https://doi.org/10.1063/1.4757868
12
M. Rahm, D. Schurig, D. A. Roberts, S. A. Cummer, D. R. Smith, and J. B. Pendry, Design of electromagnetic cloaks and concentrators using form-invariant coordinate transformations of Maxwell’s equations, Photon. Nanostructures 6(1), 87 (2008) https://doi.org/10.1016/j.photonics.2007.07.013
13
M. M. Sadeghi, H. Nadgaran, and H. Chen, Perfect field concentrator using zero index metamaterials and perfect electric conductors, Front. Phys. 9, 90 (2014) https://doi.org/10.1007/s11467-013-0374-0
14
D. Schurig, J. Mock, B. Justice, S. A. Cummer, J. B. Pendry, A. F. Starr, and D. R. Smith, Metamaterial electromagnetic cloak at microwave frequencies, Science 314(5801), 977 (2006) https://doi.org/10.1126/science.1133628
15
H. Chen, B. Hou, S. Chen, X. Ao, W. Wen, and C. T. Chan, Design and experimental realization of a broadband transformation media field rotator at microwave frequencies, Phys. Rev. Lett. 102(18), 183903 (2009) https://doi.org/10.1103/PhysRevLett.102.183903
16
M. Yan, Z. Ruan, and M. Qiu, Cylindrical invisibility cloak with simplified material parameters is inherently visible, Phys. Rev. Lett. 99(23), 233901 (2007) https://doi.org/10.1103/PhysRevLett.99.233901
17
W. Yan, M. Yan, and M. Qiu, Generalized compensated bilayer structure from the transformation optics perspective, J. Opt. Soc. Am. B 26(12), B39 (2009) https://doi.org/10.1364/JOSAB.26.000B39
18
M. M. Sadeghi, S. Li, L. Xu, B. Hou, and H. Chen, Transformation optics with Fabry-Pérot resonances, Sci. Rep. 5(1), 8680 (2015) https://doi.org/10.1038/srep08680
19
C. Navau, J. Prat-Camps, O. Romero-Isart, J. I. Cirac, and A. Sanchez, Long-distance transfer and routing of static magnetic fields, Phys. Rev. Lett. 112(25), 253901 (2014) https://doi.org/10.1103/PhysRevLett.112.253901
20
F. Sun and S. He, DC magnetic concentrator and omnidirectional cascaded cloak by using only one or two homogeneous anisotropic materials of positive permeability, Prog. Electromagnetics Res. 142, 683 (2013) https://doi.org/10.2528/PIER13092509
21
J. Prat-Camps, C. Navau, and A. Sanchez, Experimental realization of magnetic energy concentration and transmission at a distance by metamaterials, Appl. Phys. Lett. 105(23), 234101 (2014) https://doi.org/10.1063/1.4903867
22
C. Navau, J. Prat-Camps, and A. Sanchez, Magnetic energy harvesting and concentration at a distance by transformation optics, Phys. Rev. Lett. 109(26), 263903 (2012) https://doi.org/10.1103/PhysRevLett.109.263903
23
F. Sun and S. He, Transformation inside a Null-space region and a DC magnetic funnel for achieving an enhanced magnetic flux with a large gradient, Prog. Electromagnetics Res. 146, 143 (2014) https://doi.org/10.2528/PIER14031707
24
H. C. van de Hulst, Light Scattering by Small Particles, Courier Corporation, 1957
