[1] [1] Foreman S M, Holman K W, Hudson D D, et al. Remote transfer of ultrastable frequency references via fiber networks［J］. Review of Scientific Instruments, 2007, 78(2): 021101.

[2] [2] 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.

[3] [3] 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.

[4] [4] Swallows M D, Bishof M, Lin Y G, et al. Suppression of collisional shifts in a strongly interacting lattice clock［J］. Science, 2011, 331(6020): 1043-1046.

[5] [5] Hinkley N, Sherman J A, Phillips N B, et al. An atomic clock with 10-18 instability［J］. Science, 2013, 341(6151): 1215-1218.

[6] [6] 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.

[7] [7] Ushijima I, Takamoto M, Das M, et al. Cryogenic optical lattice clocks［J］. Nature Photonics, 2015, 9(3): 185-189.

[8] [8] 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.

[9] [9] Tseng W, Lin S Y, Feng K M, et al. Improving TWSTFT short-term stability by network time transfer［J］. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2010, 57(1): 161-167.

[10] [10] Desurvier E, Zervas M N. Erbium-doped fiber amplifiers: Principles and applications［M］. New York: Wiley-Interscience, 1994: 3-26.

[11] [11] Becker P C, Olsson N A, Simpson J R. Erbium-doped fiber amplifiers: Fundamentals and technology［M］. San Diego: Academic Press, 1999: 258-259.

[12] [12] Predehl K. A 920 km optical fiber link for frequency metrology at the 19th decimal place［D］. München: Ludwig-Maximilians-Universitt, 2012.

[13] [13] 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.

[14] [14] Chiodo N, Quintin N, Stefani F, et al. Cascaded optical fiber link using the internet network for remote clocks comparison［J］. Optics Express, 2015, 23(26): 33927-33937.

[15] [15] Kim J, Schnatz H, Wu D S, et al. Optical injection locking-based amplification in phase-coherent transfer of optical frequencies［J］. Optics Letters, 2015, 40(18): 4198-4201.

[16] [16] 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(3): 979-986.

[17] [17] Newbury N R, Williams P A, Swann W C. Coherent transfer of an optical carrier over 251 km［J］. Optics Letters, 2007, 32(21): 3056-3058.

[18] [18] Schediwy S W, Gozzard D, Baldwin K G H, et al. High-precision optical-frequency dissemination on branching optical-fiber networks［J］. Optics Letters, 2013, 38(15): 2893-2896.

[19] [19] Liu Q, Han S L, Wang J L, et al. Simultaneous frequency transfer and time synchronization over a 430 km fiber backbone network using a cascaded system［J］. Chinese Optics Letters, 2016, 14(7): 070602.

[20] [20] 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(26): 261109.

[21] [21] Deng X, Liu J, Jiao D D, et al. Coherent transfer of optical frequency over 112 km with instability at the 10-20 level［J］. Chinese Physics Letters, 2016, 33(11): 114202.

[22] [22] Zang Qi, Deng Xue, Liu Jie, et al. Optimization design for bidirectional erbium-doped fiber amplifier used in long distance optical frequency transfer link［J］. Acta Optica Sinica, 2017, 37(3): 0306006.

[23] [23] Cao Qun, Deng Xue, Zang Qi, et al. Two-way optical phase comparison method based on local measurement［J］. Chinese J Lasers, 2017, 44(5): 0504004.

[24] [24] Jiang H F. Development of ultra-stable laser sources and long-distance optical link via telecommunication networks［D］. Paris: Université Pierre et Marie Curie, 2010.

[25] [25] Williams P A, Swann W C, Newbury N R. High-stability transfer of an optical frequency over long fiber-optic links［J］. Journal of the Optical Society of America B, 2008, 25(8): 1284-1293.

[26] [26] 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.