[1] LU Zhaolin，SHI Shouyuan，Schuetz C，et al. Experimental demonstration of negative refraction imaging in both amplitude and phase [J]. Optics Express(S1094-4087)，2005，13(6)：2007-2012.

[2] Lezec H J，Dionne J A，Atwater H A. Negative refraction at visible frequencies [J]. Science(S0036-8075)，2007， 316(5823)：430-432.

[3] Chen H T，O'Hara J F，Taylor A J，et al. Complementary planar terahertz metamaterials [J]. Optics Express(S1094-4087)， 2007，15(3)：1084-1095.

[4] Choi M，Lee SH，Kim Y，et al. A terahertz metamaterial with unnaturally high refractive index [J]. Nature(S0028-0836)， 2011，470：369-373.

[5] Ferguson B，ZHANG Xicheng. Materials for terahertz science and technology [J]. Nature Materials(S1476-1122)，2002， 1：26-33.

[6] Linden S，Enkrich C，Wegener M，et al Magnetic response of metamaterials at 100 terahertz [J]. Science(S0036-8075)， 2004，306(5700)：1351-1353.

[7] Seo M，Park H，Koo S，et al. Terahertz field enhancement by a metallic nano slit operating beyond the skin-depth limit [J]. Nature Photonics(S1749-4885)，2009，3：152-156.

[8] HU Chenggang，LI Xiong，FENG Qing，et al. Introducing dipole-like resonance into magnetic resonance to realize simultaneous drop in transmission and reflection at terahertz frequency [J]. Journal of Applied Physics(S0021-8979)，2010， 108(5)：053103-053103.

[9] ZHANG Tiejun，XIONG Wei，ZHAO Bo，et al. Equivalent circuit analysis of ‘U’-shaped split ring resonators [J]. Journal of Modern Optics(S0950-0340)，2015：1-7.

[10] ZHANG Fuli，ZHAO Qian，ZHANG Weihong，et al. Voltage tunable short wire-pair type of metamaterial infiltrated by nematic liquid crystal [J]. Applied Physics Letters(S0003-6951)，2010，97(13)：134103.

[11] Paul O，Imhof C，L gel B，et al. Polarization-independent active metamaterial for high-frequency terahertz modulation [J]. Optics Express(S1094-4087)，2009，17(2)：819-827.

[12] Jun Y C，Brener I. Electrically tunable infrared metamaterials based on depletion-type semiconductor devices [J]. Journal of Optics(S2040-8978)，2012，14(11)：114013.

[13] CHEN Zaichun，Rahmani M，GONG Yandong，et al. Realization of Variable Three-dimensional Terahertz Metamaterial Tubes for Passive Resonance Tunability [J]. Advanced Materials(S0935-9648)，2012，24(23)：143-147.

[14] HAN Ning，CHEN Zaichun，Lim C，et al. Broadband multi-layer terahertz metamaterials fabrication and characterization on flexible substrates [J]. Optics Express(S1094-4087)，2011，19(8)：6990-6998.

[15] Timoshenko S. Analysis of bi-metal thermostats [J]. Journal of the Optical Society of America(S0030-3941)，1925，11(3)： 233-255.