[1] [1] D. H. Auston, K. P. Cheung, P. R. Smith. Picosecond photoconducting Hertzian dipoles [J]. Appl. Phys. Lett., 1984, 45:284～289

[2] [2] M. Exter, C. Fattinger, D. Grischkowsky. High-brightness terahertz beams characterized with an ultrafast detector [J]. Appl. Phys. Lett., 1989, 55:337～341

[3] [3] J. T. Darrow, B. B. Hu, X. C. Zhang et al.. Subpicosecond electromagnetic pulses from large-aperture photoconducting antennas [J]. Opt. Lett., 1990, 15:323～328

[4] [4] X. C. Zhang, B. B. Hu, J. T. Darrow et al.. Generation of femtosecond electromagnetic pulses from semiconductor surfaces [J]. Appl. Phys. Lett., 1990, 56:1011～1016

[5] [5] N. Sarukura, H. Ohtake, S. Izumida et al.. High average-power THz radiation from femtosecond laser-irradiated InAs in a magnetic field and its elliptical polarization characteristics [J]. J. Appl. Phys., 1998, 84:654～658

[6] [6] K. Liu, J. Xu, T. Yuan et al.. Terahertz radiation from InAs induced by carrier diffusion and drift [J]. Phys. Rev. B, 2006, 73:155330～155338

[7] [7] T. Yajima, N. Takearuchi. Far-infrared difference-frequency generation by picosecond laser pulses [J]. Jpn. J. Appl. Phys., 1970, 9:136～140

[8] [8] K. H. Yang, P. L. Richards, Y. R. Shen. Generation far-infrared radiation by picosecond light pulses in LiNbO3 [J]. Appl. Phys. Lett., 1971, 19:320～323

[9] [9] Q. Wu, X. C. Zhang. Ultrafast electro-optic field sensors [J]. Appl. Phys. Lett., 1996, 68:1604

[10] [10] K. Kawase, M. Sato, T. Taniuchi et al..Coherent tunable THz-wave generation from LiNbO3 with monolithic grating coupler [J]. Appl. Phys. Lett., 1997, 71:753～758

[11] [11] Y. S. Lee, T. Meade, T. B. Norris et al..Tunable narrow-band terahertz generation from periodically poled lithium niobate [J]. Appl. Phys. Lett., 2001, 78:3583～3587

[12] [12] T. Taniuchi, S. Okada, H. Nakanishi. Widely-tunable THz-wave generation in 2～20 THz range from DAST crystal by nonlinear difference frequency mixing [J]. Electron. Lett., 2004, 40(1):60～62

[13] [13] Y. Deng, R. Kersting, J. Xu et al..Millimeter wave emission from GaN high electron mobility transistor [J]. Appl. Phys. Lett., 2004, 84:70～76

[14] [14] L. E. S. Msthis, J. T. Parker. Stimulated emission in band spectrum of nitrogen [J]. Appl. Phys. Lett., 1963, 16:16～21

[15] [15] T. Y. Chang, T. J. Bridges. Laser action at 452, 459, and 541 min optically pumped CH3F [J] . Opt. Commun., 1970, 1:423～427

[16] [16] W. Schatz. Generation of tunable far-infrared radiation by optical molecular gas laser [J]. Infrared Phys. Technol., 1995, 36(1):387～393

[17] [17] R. C. Viscovini, F. C. Cruz, A. Scalabrin et al.. CHD2OH optically pumped by a waveguide CO2 laser new far-infrared laser lines from the CD2 wagging vibrational mode [J]. IEEE J. Quantum Electron., 2002, 38(8):1029～1030

[18] [18] A. D. Michele, K. Bousbahi, G. Carelli et al.. The CH3OH far-infrared laser new lines and assignments [J]. Infrared Physics & Technology, 2004, 45:243～248

[19] [19] Bao Yanxiang, Huang Xiao, Luo Xizhang et al.. Chioce of three-energy-level groups on optically pumped sub-mIlimeter wave laser medium [J]. J. Optoelectronics·Laser, 2004, 15(11):1320～1323

[20] [20] G. L. Carr, M. C. Martin, W. R. Mckinney et al..High-power terahertz radiation from relativistic electrons [J]. Nature, 2002, 420(6912):153～156

[21] [21] R. Kohler, A. Tredicucci, F. Beltram et al.. Terahertz semiconductor heterostructure laser [J]. Natrue, 2002, 417(6891):156～158

[22] [22] Q. Hu, B. S. Williams, S. Kumar et al.. Resonant-phonon-assisted THz quantum-cascade lasers with metal-metal waveguides [J]. Semi. Sci. Tech., 2005, 20:S228～S235

[23] [23] L. O. Hocker, A. Javan. Continuous 250 mW gas discharge DCN laser at 195 μm [J]. Appl. Phys. Lett., 1968, 12(4):124～129