[1] Schiller S, Tino G M, Gill P, et al. Einstein gravity explorer-a medium-class fundamental physics mission［J］. Experimental Astronomy, 2009, 23(2): 573-610.

[2] Katori H. Optical lattice clocks and quantum metrology［J］. Nature Photonics, 2011, 5(4): 203-210.

[3] Sherman J A, Lemke N D, Hinkley N, et al. High-accuracy measurement of atomic polarizability in an optical lattice clock［J］. Physical Review Letters, 2012, 108(15): 153002.

[4] Huntemann N, Okhapkin M, Lipphardt B, et al. High-accuracy optical clock based on the octupole transition in 171Yb+［J］. Physical Review Letters, 2012, 108(9): 090801.

[5] Swallows M D, Bishof M, Lin Y, et al. Suppression of collisional shifts in a strongly interacting lattice clock［J］. Science, 2011, 331(6020): 1043-1046.

[6] Hinkley N, Sherman J A, Phillips N B, et al. An atomic clock with 10-18 instability［J］. Science, 2013, 341(6151): 1215-1218.

[7] Bloom B J, Nicholson T L, Williams J R, et al. An optical lattice clock with accuracy and stability at the 10-18 level［J］. Nature, 2014, 506(7486): 71-75.

[8] Ushijima I, Takamoto M, Das M, et al. Cryogenic optical lattice clocks［J］. Nature Photonics, 2015, 9(3): 185-189.

[9] Fujieda M, Gotoh T, Nakagawa F, et al. Carrier-phase-based two-way satellite time and frequency transfer［J］. IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2012, 59(12): 2625-2630.

[10] Olivier L, Nicola C, Fabio S, et al. Cascaded optical link on a telecommunication fiber network for ultra-stable frequency dissemination［C］. SPIE, 2015, 9378: 937823.

[11] Desurvier E. Erbium-doped fiber amplifiers: Principles and applications［M］. New York: Wiley-Interscience, 1994: 3-26.

[12] Becker P C, Olsson N A, Simpson J R. Erbium-doped fiber amplifiers: Fundamentals and technology［M］. San Diego: Academic Press, 1999: 258-259.

[13] Ismail M M, Othman M A, Zakaria Z, et al. EDFA-WDM optical network design systerm［J］. Procedia Engineering, 2003, 53: 294-302.

[14] Droste S, Ozimek F, Udem T, et al. Optical-frequency transfer over a single-span 1840 km fiber link［J］. Physical Review Letters, 2013, 111(11): 110801.

[15] Predehl K. A 920 km optical fiber link for frequency metrology at the 19th decimal place［D］. München: Ludwig-Maximilians-Universitt, 2012.

[16] Nicola C, Nicolas Q, Fabio S, et al. Cascaded optical fiber link using the internet network for remote clocks comparison［J］. Optics Express, 2015, 23(26): 33927-33937.

[17] Calonico D, Bertacco E K, Calosso C E, et al. High-accuracy coherent optical frequency transfer over a doubled 642-km fiber link［J］. Applied Physics B, 2014, 117: 979-986.

[18] Ma C Q, Wu L F, Jiang Y Y, et al. Coherence transfer of sub hertz-linewidth laser light via an 82 km fiber link［J］. Applied Physics Letters, 2015, 107: 261109.

[19] Wang Lingdong, Wu Guiling, Shen Jianguo, et al. Simultaneous transfer of time and frequency over 100 km fiber link［J］. Acta Optica Sinica, 2015, 35(4): 0406004.

[20] Liu Q, Chen W, Xu D, et al. Bidirectional erbium-doped fiber amplifiers used in joint frequency and time transfer based on wavelength-division multiplexing technology［J］. Chinese Optics Letters, 2015, 13(11): 110601.

[21] Song Hongbin. Theoretical and experimental study on ASE light source, EDFA and fiber laser［D］. Harbin: Harbin Engineering University, 2005: 9-25.

[22] Qiang Zexuan. Experimental studies, analysis and design for erbium doped fiber amplifiers with low noise figure, high and flat gain［D］. Hangzhou: Zhejiang University, 2004: 12-31.

[23] Tong Zhi, Wei Huai, Li Tangjun, et al. Study on optimization of high quality EDFAs［J］. Journal of Optoelectronics·Laser, 2001, 12(9): 879-882.

[24] Yu Qian, Cui Jingcui, Wang Sihai, et al. A new method for the numerical simulation of erbium doped fiber amplifiers［J］. Chinese J Lasers, 1999, A26(7): 585-588.

[25] Jiao Dongdong, Gao Jing, Liu Jie, et al. Development and application of communication band narrow linewidth lasers［J］. Acta Physica Sinica, 2015, 64(19): 190601.