[1] [1] S D Jackson. Towards high-power mid-infrared emission from a fiber laser[J]. Nature Photonics, 2012, 6(7): 423-431.

[2] [2] Y Jeong, J Sahu, D Payne, et al.. Ytterbium-doped large-core fiber laser with 1.36 kW continuous-wave output power[J]. Opt Express, 2004, 12(25): 6088-6092.

[3] [3] Y Tang, C Huang, S Wang, et al.. High-power narrow-bandwidth thulium fiber laser with an all-fiber cavity[J]. Opt Express, 2012, 20(16): 17539-17544.

[4] [4] Z Yunjun, Y Baoquan, J Youlun, et al.. LD-cladding-pumped 50 pm linewidth Tm3+-doped silica fiber laser[J]. Opt Express, 2008, 16(11): 7715-7719.

[5] [5] F Wang, D Shen, D Fan, et al.. Spectrum narrowing of high power Tmfiber laser using a volume Bragg grating[J]. Opt Express, 2010, 18(9): 8937-8941.

[6] [6] Du Geguo, Zhao Junqing, Zhang Lingcong, et al.. Studies on Tm-doped double-clad fiber lasers[J]. Laser and Optoelectronics Progress, 2012, 49(2): 020005.

[7] [7] Wang Fei, Shen Deyuan, Long Jingyu, et al.. High-power widely-tunable Tmfiber master oscillator power amplifier[J]. Chinese J Lasers, 2013, 40(6): 0602009.

[8] [8] S D Jackson, T A King. High-power diode-cladding-pumped Tm-doped silica fiber laser[J]. Opt Lett, 2008, 23(18): 1462-1464.

[9] [9] S D Jackson. Cross relaxation and energy transfer upconversion processes relevant to the functioning of 2 μm Tm3+-doped silica fiber lasers[J]. Opt Commun, 2004, 230(1): 197-203.

[10] [10] T Ehrenreich, R Leveille, I Majid, et al.. 1-kW, all-glass Tm fiber laser[C]. SPIE, 2010, 7580: 758016.

[11] [11] G D Goodno, L D Book, J E Rothenberg. Low-phase-noise, single-frequency, single-mode 608 W thulium fiber amplifier[J]. Opt Lett, 2009, 34(8): 1204-1206.

[12] [12] L Pearson, J W Kim, Z Zhang, et al.. High-power linearly-polarized single-frequency thulium-doped fiber master-oscillator power-amplifier[J]. Opt Express, 2010, 18(2): 1607-1612.

[13] [13] L Shah, R A Sims, P Kadwani, et al.. Integrated Tmfiber MOPA with polarized output and narrow linewidth with 100 W average power[J]. Opt Express, 2012, 20(18): 20558-20563.

[14] [14] Liu Jiang, Wang Pu. High-power narrow-bandwidth continuous wave thulium-doped all-fiber laser[J]. Chinese J Lasers, 2013, 40(1): 0102001.

[15] [15] Liu Jiang, Wang Pu. High-power passively mode-locked thulium-doped femtosecond fiber laser at 2.0 μm[J]. Chinese J Lasers, 2012, 39(9): 0902001.

[16] [16] Liu Jiang, Wang Pu. Thulium-doped all-fiber broadband superfluorescent source at 2 μm wavelength[J]. Chinese J Lasers, 2013, 40(2): 0202006.