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

[2] Ferguson B, Zhang Xicheng. Materials for terahertz science and technology ［J］. Nature, 2002, 1: 26-33.

[4] Chang T Y, Bridge T J. Reviews of IR & MMW ［M］. Plenum Press, 1984: 1-8.

[7] Behn R, Andre M, et al. Buffer gases to increase the efficiency of an optically pumped far infrared D2 O laser ［J］. IEEE J. Quantum Electron., 1985, 21(8): 1278-1286.

[8] Li Ming, Fortin J, Kim J Y, et al. Dielectric constant measurement of thin films using goniometric terahertz time-domain spectroscopy ［J］. IEEE Quantum Electronics, 2001, 7(4): 624-629.

[9] Bao Yangxiang, Huang Xiao, He Zhihong, et al. Effects of pump source on spectra of optically pumped sub-millimeter wave laser ［J］. International Journal of Infrared and Millimeter Waves, 2006, 27: 1315-1322.

[11] Sargent M, Scully M O, Lamb W E. Laser Physics ［M］. Addision-Wesley Publishing Com. Inc., 1974: 189-210.

[12] Herzberg G. Molecular Spectra and Molecular Structure: II Infrared and Raman Spectra of Polyatomic Molecules ［M］. Science Press, 1986: 200-250 (in Chinese).

[13] Mellau G, Mikhailenko S N, Starikova E N, et al. Rotational levels of the (000) and (010) states of D2 O from hot emission spectra in the 320～860 cm-1 region ［J］. Journal of Molecular Spectroscopy, 2004, 224: 32-60.

[14] Townes C H, Schawlow A L. Microwave Spectroscopy ［M］. New York: McGrew-Hill, 1955: 250-280.

[15] Hodges D T. A review of advances in optically pumped FIR lasers ［J］. Infrared Physics, 1978, 18: 375-384.

[16] Panock R L, Temkin R J. Interaction of two laser fields with a three-level molecular system ［J］. Quantum Electronics, 1977, QE-13(6): 425-434.

[17] Drozdowicz Z, Temkin R J, Lax B. Laser pumped molecular lasers-part I: Theory ［J］. Quantum Electronics, 1979, QE-15(3): 170-178.