Based on a space folding transformation, we propose a new way to hide an object in full space,namely, to cover-up the scattering of the hidden object with the scattering of a background object so that only the scattering of the background object can be detected by an outside observer and the hidden object disappears electromagnetically (a very weak ``ghost image'' or perturbation may appear inside the strong background object image in an experiment). The present method is essentially different from previous methods of cloaking an object. This work furthers efforts to achieve invisibility and conceal an object in a real environment in full space.
1. Pendry, J. B., D. Schurig, and D. R. Smith, "Controlling electromagnetic fields," Science, Vol. 312, 1780-1782, 2006. doi:10.1126/science.1125907
2. Schurig, D., J. J. Mock, B. J. Justice, S. A. Cummer, J. B. Pendry, A. F. Starr, and D. R. Smith, "Metamaterial electromagnetic cloak at microwave frequencies," Science, Vol. 314, No. 5801, 977-980, 2006. doi:10.1126/science.1133628
3. Ma, Y., Y. Liu, L. Lan, T. Wu, W. Jiang, C. K. Ong, and S. He, "First experimental demonstration of an isotropic electromagnetic cloak with strict conformal mapping," Sci. Rep., Vol. 3, 2182, 2013.
4. Xu, T., Y. C. Liu, Y. Zhang, C. K. Ong, and Y. G. Ma, "Perfect invisibility cloaking by isotropic media," Phys. Rev. A, Vol. 86, No. 4, 043827, 2012. doi:10.1103/PhysRevA.86.043827
5. Kante, B., D. Germain, and A. de Lustrac, "Experimental demonstration of a nonmagnetic metamaterial cloak at microwave frequencies," Phys. Rev. B, Vol. 80, No. 20, 201104, 2009. doi:10.1103/PhysRevB.80.201104
6. Howell, J. C., J. B. Howell, and J. S. Choi, "Amplitude-only, passive, broadband, optical spatial cloaking of very large objects," Appl. Opt., Vol. 53, No. 9, 1958-1963, 2014. doi:10.1364/AO.53.001958
8. Xu, S., X. Cheng, S. Xi, R. Zhang, H. O. Moser, Z. Shen, and H. Chen, "Experimental demonstration of a free-space cylindrical cloak without superluminal propagation," Phys. Rev. Lett., Vol. 109, No. 22, 223903, 2012. doi:10.1103/PhysRevLett.109.223903
9. Lan, L., F. Sun, Y. Liu, C. K. Ong, and Y. Ma, "Experimentally demonstrated a unidirectional electromagnetic cloak designed by topology optimization," Appl. Phys. Lett., Vol. 103, No. 12, 121113, 2013. doi:10.1063/1.4821951
10. Lai, Y., 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., Vol. 102, No. 9, 093901, 2009. doi:10.1103/PhysRevLett.102.093901
11. Vasquez, F. G., G. W. Milton, and D. Onofrei, "Active exterior cloaking for the 2D Laplace and Helmholtz equations," Phys. Rev. Lett., Vol. 103, No. 7, 073901, 2009. doi:10.1103/PhysRevLett.103.073901
12. Selvanayagam, M. and G. V. Eleftheriades, "Discontinuous electromagnetic fields using orthogonal electric and magnetic currents for wavefront manipulation," Opt. Express, Vol. 21, No. 12, 14409-14429, 2013. doi:10.1364/OE.21.014409
13. Zhang, P., Y. Jin, and S. He, "Obtaining a nonsingular two-dimensional cloak of complex shape from a perfect three-dimensional cloak," Appl. Phys. Lett., Vol. 93, No. 24, 243502, 2008. doi:10.1063/1.3021067
14. Zhang, J., L. Liu, Y. Luo, S. Zhang, and N. A. Mortensen, "Homogeneous optical cloak constructed with uniform layered structures," Opt. Express, Vol. 19, No. 9, 8625-8631, 2011. doi:10.1364/OE.19.008625
15. Chen, H. and B. Zheng, "Broadband polygonal invisibility cloak for visible light," Sci. Rep., Vol. 2, 255, 2012.
16. Chen, H., B. Zheng, L. Shen, H. Wang, X. Zhang, N. I. Zheludev, and B. Zhang, "Ray-optics cloaking devices for large objects in incoherent natural light," Nat. Commun., Vol. 4, 2652, 2013.
17. Fleury, R. and A. Alu, "Cloaking and invisibility: A review," Forum for Electromagnetic Research Methods and Application Technologies (FERMAT), Vol. 1, No. 7, 1-24, 2014.
18. Pendry, J. B., "Controlling Light on the Nanoscale," Progress In Electromagnetics Research, Vol. 147, 117-126, 2014.