[1] Chen H T, Padilla W J. Zide J M O, et al. Active terahertz metamaterial devices[J]. Nature, 444, 597-600(2006).

[2] Chen H T. O'Hara J F, Azad A, et al. Experimental demonstration of frequency-agile terahertz metamaterials[J]. Nature Photonics, 2, 295-298(2008).

[3] Shen N H, Massaouti M, Gokkavas M et al. Optically implemented broadband blueshift switch in the terahertz regime[J]. Physical Review Letters, 106, 037403(2011).

[4] Liu X W, Liu H J, Sun Q B et al. Metamaterial terahertz switch based on split-ring resonator embedded with photoconductive silicon[J]. Applied Optics, 54, 3478-3483(2015).

[5] Landy N I, Bingham C M, Tyler T et al. Design, theory, and measurement of a polarization-insensitive absorber for terahertz imaging[J]. Physical Review B, 79, 125104(2009).

[6] Fang B, Li B Y. Peng Y D, at al. Polarization-independent multiband metamaterials absorber by fundamental cavity mode of multilayer microstructure[J]. Microwave and Optical Technology Letters, 61, 2385-2391(2019).

[7] Xie J W, Jing X F. Design of an all-dielectric ultra-period grating terahertz broadband perfect reflector[J]. Journal of Optoelectronics·Laser, 30, 365-375(2019).

[8] Tao H, Landy N I, Bingham C M et al. A metamaterial absorber for the terahertz regime: design, fabrication and characterization[J]. Optics Express, 16, 7181-7188(2008).

[9] Ye Y Q, Jin Y, He S L. Omnidirectional, polarization-insensitive and broadband thin absorber in the terahertz regime[J]. Journal of the Optical Society of America B, 27, 498-504(2010).

[10] Hu F R, Wang L, Quan B G et al. Design of a polarization insensitive multiband terahertz metamaterial absorber[J]. Journal of Physics D: Applied Physics, 46, 195103(2013).

[11] Wei M L, Song Z Y, Deng Y D et al. Large-angle mid-infrared absorption switch enabled by polarization-independent GST metasurfaces[J]. Materials Letters, 236, 350-353(2018).

[12] Liu M K, Hwang H Y, Tao H et al. Terahertz-field-induced insulator-to-metal transition in vanadium dioxide metamaterial[J]. Nature, 487, 345-348(2012).

[13] Zhao Y, Huang Q P, Cai H L et al. A broadband and switchable VO2-based perfect absorber at the THz frequency[J]. Optics Communications, 426, 443-449(2018).

[14] Huang Y Q, Li Y, Li Z P et al. Tunable mid-infrared broadband absorber based on W/VO2 square nano-pillar array[J]. Acta Optica Sinica, 39, 0316001(2019).

[15] Zhang Y, Feng Y J, Zhu B et al. Graphene based tunable metamaterial absorber and polarization modulation in terahertz frequency[J]. Optics Express, 22, 22743-22752(2014).

[16] Zhao Y T, Wu B, Huang B J et al. Switchable broadband terahertz absorber/reflector enabled by hybrid graphene-gold metasurface[J]. Optics Express, 25, 7161-7169(2017).

[17] Huang M L, Cheng Y Z, Cheng Z Z et al. Design of a broadband tunable terahertz metamaterial absorber based on complementary structural graphene[J]. Materials, 11, 540-549(2018).

[18] Wang Y, Leng Y B, Dong L H et al. Design of tunable metamaterial absorber based on graphene-metal hybrid structure[J]. Acta Optica Sinica, 38, 0716001(2018).

[19] Zhao X G, Fan K, Zhang J D et al. Optically tunable metamaterial perfect absorber on highly flexible substrate[J]. Sensors and Actuators A: Physical, 231, 74-80(2015).

[20] Cheng Y Z, Gong R Z, Cheng Z Z. A photoexcited broadband switchable metamaterial absorber with polarization-insensitive and wide-angle absorption for terahertz waves[J]. Optics Communications, 361, 41-46(2016).

[21] Yuan S, Yang R C, Xu J P et al. Photoexcited switchable single-/dual-band terahertz metamaterial absorber[J]. Materials Research Express, 6, 075807(2019).

[22] Yuan C, Zhao X L, Cao X L et al. Optical control of terahertz nested split-ring resonators[J]. Optical Engineering, 52, 087111(2013).

[23] Dao R N, Kong X R, Zhang H F et al. A tunable broadband terahertz metamaterial absorber based on the vanadium dioxide[J]. Optik, 180, 619-625(2019).

[24] Liu J X, Zhang K L, Liu X K et al. Switchable metamaterial for enhancing and localizing electromagnetic field at terahertz band[J]. Optics Express, 25, 13944(2017).

[25] Ji H Y, Zhang B, Wang G C et al. Photo-excited multi-frequency terahertz switch based on a composite metamaterial structure[J]. Optics Communications, 412, 37-40(2018).

[26] Yao G, Ling F R, Yue J et al. Dual-band tunable perfect metamaterial absorber in the THz range[J]. Optics Express, 24, 1518(2016).