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

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

[3] [3] E Pickwell, V P Wallace. Biomedical applications of terahertz technology[J]. J Phys D: Appl Phys, 2006, 39(17): R301.

[4] [4] P Gaal, M B Raschek, K Reimann, et al.. Measuring optical frequencies in the 0-40 THz range with non-synchronized electro-optic sampling[J]. Nature, 2007, 1(10): 577-580.

[5] [5] M Naftaly, R A Dudley, J R Fletcher, et al.. Frequency calibration of terahertz time-domain spectrometers[J]. J Opt Soc Am B, 2009, 26(7): 1357-1362.

[6] [6] M Naftaly, R A Dudley, J R Fletcher, et al.. An etalon-based method for frequency calibration of terahertz time-domain spectrometers (THz TDS)[J]. Opt Commum, 2010, 283(9): 1849-1853.

[7] [7] T Udem, R Holzwarth, T W Hansch. Optical frequency metrology[J]. Nature, 2002, 416(14): 233-237.

[8] [8] Meng Fei, Cao Shiying, Cai Yue, et al.. Study of femtosecond fiber comb and absolute optical frequency measurement[J]. Acta Physcis Sinica, 2011, 60(10): 100601.

[9] [9] S Yokoyama, R Nakamura, M Nose, et al.. Terahertz spectrum analyzer based on a terahertz frequency comb[J]. Opt Express, 2008, 16 (17): 13052-13061.

[10] [10] T Yasui, R Nakamura, K Kawamoto, et al.. Real-time monitoring of continuous-wave terahertz radiation using a fiber-based terahertzcomb- referenced spectrum analyzer[J]. Opt Express, 2009, 17(19): 17034-17043.

[11] [11] T Yasui, S Yokoyama, H Inaba, et al.. Terahertz frequency metrology based on frequency comb[J]. IEEE Journal of Selected Topics in Quantum Electronics, 2010, 17(1): 191-201.

[12] [12] H Ito, S Nagano, M Kumagai, et al.. Terahertz frequency counter with a fractional frequency uncertainty at the 10_17 level[J]. Appl Phys Express, 2013, 6(10): 102202.

[13] [13] H Fuser, R Judaschke, M Bieler. High-precision frequency measurements in the THz spectral region using an unstabilized femtosecond laser[J]. Appl Phys Lett, 2011, 99(12): 121111.

[14] [14] D S Yee, Y D Jang, Y C Kim, et al.. Terahertz spectrum analyzer based on frequency and power measurement[J]. Opt Lett, 2010, 35(15): 2532-2534.

[15] [15] Meng Fei, Cao Shiying, Zhao Guangzhen, et al.. Application of an Er∶doped fiber comb for Sr lattice clock[J]. Chinese J Lasers, 2015, 42(7): 0702012.

[16] [16] Wang Guochao, Wei Chunhua, Yan Shuhua. Wavelength selection and non-ambiguity range analysis for optical-comb-referenced multiwavelength absolute distance measurement[J]. Acta Optica Sinica, 2014, 34(4): 0412002.

[17] [17] Wang Guochao, Yan Shuhua, Yang Jun, et al.. Theoretical modeling analysis for precise space ranging based on cross-correlation of femtosecond optical frequency comb[J]. Acta Optica Sinica, 2015, 35(4): 0412002.