[1] [1] Tonouchi Masayoshi. Cutting-edge terahertz technology[J]. Nature Photonic, 2007, 1(2): 97-105.

[2] [2] Gwyn P Williams. Filling the terahertz gap-high power sources and applications[J]. Rep Prog Phys, 2006, 69(2):301-326.

[3] [3] Ferguson B, Zhang X C. Materials for terahertz science and technology[J]. Nat Mater, 2002, 1(1): 26-33.

[4] [4] Siegel P H. Terahertz technology[J]. Microwave Theory and Techniques, IEEE Transactions on, 2002, 50(3): 910-928.

[5] [5] Marco Rahm, Li Jiusheng, Willie J Padilla. THz wave modulators：a brief review on different modulation techniques[J]. Journal of Infrared, Millimeter, and Terahertz Waves, 2012, 34: 1-27.

[6] [6] Sensale-Rodriguez B, Yan R, Kelly M M, et al. Broadband graphene terahertz modulators enabled by intraband transitions[J]. Nat Commun. 2012, 3: 780.

[7] [7] Takanori Okada, Koichiro Tanaka. Photo-designed terahertz devices[J]. Scientific Reports, 2011, 1: 121.

[8] [8] Chen Changhong, Zhu Yanhan, Zhao Yong, et al. VO2 multidomain heteroepitaxial growth and terahertz transmission modulation[J]. Applied Physics Letters, 2010, 97(21): 211905-211905-3.

[9] [9] Tae-In Jeon, D Grischkoysky. Nature of conduction in doped silicon[J]. Phys Rev Lett, 1997, 78: 1106-1109.

[10] [10] Tang Hao, Zhu Liguo, Zhao Liang, et al. Carrier dynamics in Si nanowires fabricated by metal-assisted chemical etching[J]. ACS Nano, 2012, 6(9): 7814-7819.

[11] [11] Giriraj Jnawali, Rao Yi, Yan Hugen, et al. Observation of a transient decrease in terahertz conductivity of single-layer graphene induced by ultrafast optical excitation[J]. Nano Lett, 2013, 13: 524-530.

[12] [12] George P A, Strait J, Dawlaty J, et al. Ultrafast optical-pump terahertz-probe spectroscopy of the carrier relaxation and recombination dynamics in epitaxial graphene[J]. Nano Lett, 2008, 8(12): 4248-4251.

[13] [13] J M Dawlty, S Shivaraman, J Strait, et al. Measurement of the optical absorption spectra of epitaxial graphene from terahertz to visible [J]. Appl Phys Lett, 2008, 93(13):131905.

[14] [14] Liu Ming, Yin Xiaobin, Erick Ulin Acila, et al. A graphene-based broadband optical modulator[J]. Nature, 2011, 474: 64-67.

[15] [15] Efetov D K, Kim P. Controlling electron-phonon interactitons in graphene at ultrahigh carrier densities[J]. Phys Rev Lett, 2010, 105(25): 256805.

[16] [16] Bolotin K I, Sikes K J, Jiang Z, et al. Ultrahigh electron mobility in suspended grapheme[J]. Solid State Communications, 2008, 146(9/10): 351-355.

[17] [17] Zhu Liguo. Terahertz spectroscopy and itsapplications on study of carrier dynamics [D]. Beijing: Tsinghua University, 2011. (in Chinese)

[18] [18] Martin Dressel, George Grüner. Electrodynamics of Solids[M]. Cambridge: Cambridge University Press, 2002.