[1] [1] Veselago V G. The electrodynamics of substances with simultaneously negative values of permittivity and permeability [J]. Sov. Phys. Usp.,1968,10(4):509-514

[2] [2] J. B. Pendry. Negative refraction makes a perfect lens [J]. Phys. Rev. Lett.,2000,85:3966-3969

[3] [3] Z. M. Zhang,C. J. Fu. Unusual photon tunneling in the presence of a layer with a negative refractive index [J]. Appl. Phys. Lett.,2002,80(6):1097

[4] [4] L. Chen,S. L. He,L. F. Shen. Finite-size effects of a left-handed material slab on the image quality [J]. Phys. Rev. Lett.,2004,92(10):107404

[5] [5] J. B. Pendry,A. J. Holden,W. J. Stewart et al.. Extremely low frequency plasmons in metallic mesostructures [J]. Phys. Rev. Lett.,1996,76(25):4773-4776

[6] [6] J. B. Pendry,A. J. Holden,D. J. Robbins et al.. Magnetism from conductors and enhanced nonlinear phenomena [J]. IEEE T. Microwave Theory Tech.,1999,47(11):2075-2084

[7] [7] D. R. Smith,W. J. Padilla,D. C. Vier et al.. Composite medium with simultaneously negative permeability and permittivity [J]. Phys. Rev. Lett.,2000,84(18):4184-4187

[8] [8] Q. Thommen,P. Mandel. Left-handed properties of erbium-doped crystals [J]. Opt. Lett.,2006,31(12):1803-1805

[9] [9] S. Forteinopoulou,C. M. Soukoulis. Electromagnetic wave propagation in two-dimensional photonic crystals:a study of anomalous refractive effects [J]. Phys. Rev. B,2005,72(16):165112

[10] [10] R. X. Wu. Effective negative refraction index in periodic metal-ferrite-metal film composite[J]. J. Appl. Phys.,2005,97(7):076105

[11] [11] M.Oktel. Electromagnetically induced left-handedness in a dense gas of three-level atoms [J]. Phys. Rev. A,2004,70(5):053806

[12] [12] Q. Thommen,P. Mandel. Electromagnetically induced left handedness in optically excited four-level atomic media [J]. Phys. Rev. Lett.,2006,96(5):053601

[13] [13] J. Q. Shen,Z. C. Ruan,S. He. How to realize a negative refractive index material at the atomic level in an optical frequency range [J]. J. Zhejiang Univ. Sci.,2004,5(11):1322-1326

[14] [14] H. J. Zhang,S. Q. Gong,Y. P. Niu et al.. Negative refractive index in a four-level atomic system [J]. Chin. Phys. Lett.,2006,23(7):1769-1772

[15] [15] D. M. Cook. The Theory of the Electromagnetic Field [M]. New Jersey :Prentice-Hall,1975. Chap. 11

[16] [16] Jackson J D. Classical Electrodynamics [M]. New York:Wiley(3rd),1998. 159-162