[1] D J Richardson, J Nilsson, W A Clarkson. High power fiber lasers: current status and future perspectives. Journal of Optical Society of America B, 27, B63-B92(2010).

[2] A Galvanauskas. High power fiber lasers. Optics & Photonics News, 15, 42-47(2004).

[3] M N Zervas, C A Codemard. High power fiber lasers: A review. IEEE Journal of Selected Topics in Quantum Electronics, 20, 219-241(2014).

[4] J Hecht. High-power fiber lasers. Optics and Photonics News, 29, 30-37(2018).

[5] B Boulanger, G Goodno, S Jiang, et al. Focus issue introduction: advanced solid-state lasers. Optics Express, 27, 20938-20941(2019).

[6] J Zuo, X Lin. High-power laser systems. Laser Photonics Reviews, 16, 2100741(2022).

[7] A Braglia, A Califano, Y Liu, et al. Architectures and components for high power CW fiber lasers. International Journal of Modern Physics B, 28, 1442001(2014).

[8] S K Kalyoncu, B Mete, A Yenıay. Diode-pumped triple-clad fiber MOPA with an output power scaling up to 4.67  kW. Optics Letters, 45, 1870-1873(2020).

[9] M Stark. Over 50 percent wall-plug efficiency fiber laser. Laser Technik Journal, 14-19(2016).

[10] [10] Wang Y, Kitahara R, Kiyoyama W, et al. 8kW singlestage allfiber Ybdoped fiber laser with a BPP of 0.50 mmmrad[C]Proc of SPIE, 2020, 11260: 1126022.

[11] Z Han, Y Zheng, H Wang, . Home-made 6.7 kW narrow linewidth triple-cladding fiber laser. Infrared and Laser Engineering, 51, 20210849(2022).

[12] Q Xiao, D Li, Y Huang, et al. Directly diode and bi-directional pumping 6 kW continuous-wave all-fibre laser. Laser Physics, 28, 125107(2018).

[13] Xin Tian, Binyu Rao, Meng Wang, et al. 5 kW near single mode output of narrow linewidth laser with simple MOPA structure. High Power Laser and Particle Beams, 34, 121002(2022).

[16] B Yang, P Wang, H Zhang, et al. 6 kW single mode monolithic fiber laser enabled by effective mitigation of the transverse mode instability. Optics Express, 29, 26366-26374(2021).

[17] Z Huang, Q Shu, R Tao, et al. >5 kW record high power narrow linewidth laser from traditional step-index monolithic fiber amplifier. IEEE Photonics Technology Letters, 33, 1181-1184(2021).

[19] Cong Gao, Nian Liu, Fengyun Li, . 17.4 kW (1+1) long distance side-pumped laser fiber. High Power Laser and Particle Beams, 34, 051002(2022).

[22] X Chen, F Lou, Y He, . Home-made 10 kW fiber laser with high efficiency. Acta Optica Sinica, 39, 0336001(2019).

[25] X Xi, B Yang, H Zhang, . 20 kW monolithic fiber amplifier directly pumped by LDs. High Power Laser and Particle Beams, 35, 021001(2023).

[26] [26] IPG Photonics. Recent progress in scaling SM high power fiber lasers to 10 kW at IPG photonics [C] Solid State Diode Laser Technology Review, 2009.

[28] L Zhang, F Lou, M Wang, . Yb-doped triple-clad fiberfor nearly 10 kW level tandem-pumped output. Chinese Journal of Lasers, 48, 1315001(2021).

[30] Q Fang, J Li, W Shi, et al. 5 kW near-diffraction-limited and 8 kw high-brightness monolithic continuous wave fiber lasers directly pumped by laser diodes. IEEE Photonics Journal, 9, 1-7(2017).

[34] Peng Wang, Xiaoming Xi, Hanwei Zhang, . Laser-diode-pumped fiber laser amplifier for 13 kW high-beam-quality output. High Power Laser and Particle Beams, 34, 121001(2022).

[37] [37] Siewert N. High power industrial grade fiber lasers[C]IME on High Energy Lasers. DESY, Hamburg: 2014.

[38] B Yang, C Shi, H Zhang, et al. Monolithic fiber laser oscillator with record high power. Laser Physics Letters, 15, 75106(2018).

[39] Y Wen, P Wang, B Yang, et al. First demonstration and comparison of 5 kW monolithic fiber laser oscillator pumped by 915 nm and 981 nm LDs. Photonics, 9, 716(2022).

[40] [40] Möller F, Krämer R G, Matzdf C, et al. Comparison between bidirectional pumped Ybdoped all fiber singlemode amplifier oscillat setup up to a power level of 5 kW [C]ASSL 2018: AM2A.3.

[41] R G Krämer, F Möller, C Matzdorf, et al. Extremely robust femtosecond written fiber Bragg gratings for an ytterbium-doped fiber oscillator with 5  kW output power. Optics Letters, 45, 1447-1450(2020).

[42] [42] Llc L O. CELIGHT series fiber laser modules YLE 30054005[EBOL]. [20230405]. https:resource.lumentum.coms3fspublictechnicallibraryitemscelightdsclae.pdf.

[50] M N Zervas. High power ytterbium-doped fiber lasers—fundamentals and applications. International Journal of Modern Physics B, 28, 1442009(2014).

[51] [51] Shcherbakov E A, Fomin V V, Abramov A A, et al. Industrial grade 100 kW power CW fiber laser[C]Advanced SolidState Lasers Congress, Paris, France, 2013: ATh4A.2.

[52] T Eidam, S Hanf, E Seise, et al. Femtosecond fiber CPA system emitting 830 W average output power. Optics Letters, 35, 94-96(2010).

[53] [53] Wirth C, Schreiber T, Rekas M, et al. Highpower linearpolarized narrow linewidth photonic crystalfiber amplifier[C]Proceedings of SPIE, 2010, 7580: 75801H.

[54] A Kobyakov, M Sauer, D Chowdhury. Stimulated Brillouin scattering in optical fibers. Advances in Optics and Photonics, 2, 1-59(2010).

[55] [55] Matiek D, Hanzard PH, Boukhaoui D, et al. Influence of stimulated Brillouin scattering on the dynamics of a selfpulsing fiber laser[C]2017 Conference on Lasers ElectroOptics Europe & European Quantum Electronics Conference (CLEOEuropeEQEC), 2017.

[56] K Lee, K Lee, Y Kim, et al. Transverse mode instability induced by stimulated Brillouin scattering in a pulsed single-frequency large-core fiber amplifier. Applied Optics, 54, 189-194(2015).

[57] [57] Okhotnikov O G. Fiber Lasers[M]. Weinheim, Germany: WileyVCH, 2012.

[58] [58] Agrawal G P. Nonlinear Fiber Optics[M]. 4th ed. Burlington, USA: Academic Press, 2007: 367.

[59] C Zhang, L Xie, H Li, et al. SRS-induced spatial-spectral distortion and its mitigation strategy in high-power fiber amplifiers. IEEE Photonics Journal, 14, 3016605(2022).

[60] C Shi, R T Su, H W Zhang, et al. Experimental study of output characteristics of bi-directional pumping high power fiber amplifier in different pumping schemes. IEEE Photonics Journal, 9, 1502910(2017).

[61] X Wang, R Tao, B Yang, . Relationship between transverse mode instability and stimulated raman scattering in ytterbium doped all-fiber laser oscillator. Chinese Journal of Lasers, 45, 0801001(2018).

[62] Y Ye, X Xi, C Shi, et al. Experimental study of 5-kW high-stability monolithic fiber laser oscillator with or without external feedback. IEEE Photonics Journal, 11, 1503508(2019).

[63] K Hejaz, M Shayganmanesh, R Rezaei-nasirabad, et al. Modal instability induced by stimulated Raman scattering in high-power Yb-doped fiber amplifiers. Optics Letters, 42, 5274-5277(2017).

[64] S Naderi, I Dajani, J Grosek, et al. Theoretical and numerical treatment of modal instability in high-power core and cladding-pumped Raman fiber amplifiers. Optics Express, 24, 16550-16565(2016).

[65] Z Li, C Li, Y Li, et al. Impact of stimulated Raman scattering on the transverse mode instability threshold. IEEE Photonics Journal, 10, 1502709(2018).

[66] B Mcmillen, B Zhang, K P Chen, et al. Ultrafast laser fabrication of low-loss waveguides in chalcogenide glass with 0.65 dB/cm loss. Optics Letters, 37, 1418-1420(2012).

[67] C Jauregui, J Limpert, A Tunnermann. High-power fibre lasers. Nature Photonics, 7, 861-867(2013).

[68] Rumao Tao, Xiaolin Wang, Pu Zhou. Comprehensive theore-tical study of mode instability in high power fiber lasers by employing a universal model and its implications. IEEE Journal of Selected Topics in Quantum Electronics, 24, 0903319(2018).

[69] A V Smith, J J Smith. Increasing mode instability thresholds of fiber amplifiers by gain saturation. Optics Express, 21, 15168-15182(2013).

[70] J Lægsgaard. Optimizing Yb concentration of fiber amplifiers in the presence of transverse modal instabilities and photo-darkening. Applied Optics, 55, 1966-1970(2016).

[71] D Alekseev, V Tyrtyshnyy, M Kuznetsov, et al. Transverse-mode instability in high-gain few-mode Yb³⁺-doped fiber amplifiers with a 10-μm core diameter with or without backward reflection. IEEE Journal of Selected Topics in Quantum Electronics, 24, 5100608(2018).

[72] M N Zervas. Transverse mode instability, thermal lensing and power scaling in Yb³⁺-doped high-power fiber amplifiers. Optics Express, 27, 19019-19041(2019).

[73] K Hejaz, M Shayganmanesh, S Azizi, et al. Transverse mode instability of fiber oscillators in comparison with fiber amplifiers. Laser Physics Letters, 15, 55102(2018).

[74] C Jauregui, C Stihler, J Limpert. Transverse mode instability. Advances in Optics and Photonics, 12, 429-484(2020).

[75] B Yang, Z Hanwei, S Chen, et al. 3.05 kW monolithic fiber laser oscillator with simultaneous optimizations of stimulated Raman scattering and transverse mode instability. Journal of Optics, 20, 25802(2018).

[76] [76] Wang X, Tao R, Xiao H, et al. Experimental studies of mode instability thermal induced effects in allfiber amplifier[C]Advanced SolidState Lasers Congress, Paris, Optical Society of America, 2013: JTh2A.44.

[77] R Tao, H Xiao, H Zhang, et al. Dynamic characteristics of stimulated Raman scattering in high power fiber amplifiers in the presence of mode instabilities. Optics Express, 26, 25098(2018).

[78] Y Wan, B Yang, X Xi, . Transverse mode instability effect of fiber lasers with different pump wavelengths. Infrared and Laser Engineering, 51, 20210256(2022).

[79] [79] Walny M, Abramczyk J, Jacobson N, et al. Mechanical reliability of double clad fibers in typical fiber laser deployment conditions[C]Proc of SPIE, 2016, 9728: 97283A.

[80] J W Dawson, M J Messerly, R J Beach, et al. Analysis of the scalability of diffraction-limited fiber lasers and amplifiers to high average power. Optics Express, 16, 13240-13266(2008).

[81] J Zhu, P Zhou, Y Ma, et al. Power scaling analysis of tandem-pumped Yb-doped fiber lasers and amplifiers. Optics Express, 19, 18645-18654(2011).

[82] X Wang, Y Wen, H Zhang, . Ytterbium doped variety core diameter fiber laser: current situation and develop tendency. Chinese Journal of Lasers, 49, 2100001(2022).

[83] [83] Wang X L, Ye Y, Xi X M, et al. One type of gain fiber with vary ce diameter along the lengthways: China, CN208569093U[P]. 20190301. (in Chinese)

[84] [84] Wang X, Xi X, Xu X, et al. Ytterbiumdoped fiber laser oscillat using specific wavelength b f pumping: China, 212810843U [P]. 20210326. (in Chinese)

[85] [85] Wang X L, Ye Y, Shi C, et al. One type of all fiber laser oscillats based on gain fiber with vary ce diameter along the lengthways: China, CN208522240U[P]. 20190219. (in Chinese)e)

[88] X Wang, P Lv, H Zhang, . Fiber laser simulation software SeeFiberLaser and fiber laser tool collections SFTool. Chinese Journal of Lasers, 44, 0506002(2017).

[89] R Tao, P Ma, X Wang, et al. 1.3 kW monolithic linearly polarized single-mode master oscillator power amplifier and strategies for mitigating mode instabilities. Photonics Research, 3, 86-93(2015).

[90] [90] Zhang H, Wang X, Xi X, et al. Highpower singlemode fiber laser: China, CN216251598U[P]. 20220408. (in Chinese)

[91] [91] Xi X, Wang X, Xu X, et al, Ytterbiumdoped fiber laser using specific wavelength b pump China, CN111934179A[P]. 20201113. (in Chinese)

[92] Y Wan, X Xi, B Yang, et al. Enhancement of TMI threshold in Yb-doped fiber laser by optimizing pump wavelength. IEEE Photonics Technology Letters, 13, 656-659(2021).

[93] Y Wan, B Yang, P Wang, et al. Optimizing the pump wavelength to improve the transverse mode instability threshold of fiber laser by 3.45 times. Journal of Modern Optics, 68, 967-974(2021).

[94] [94] Wan Y. Research on suppression of transverse mode instability effect of fiber laser based on pump optimization [D]. Changsha: National University of Defense Technology, 2021. (in Chinese)

[95] L Zeng, W Xiaolin, Y Yun, et al. High power ytterbium-doped fiber lasers employing longitudinal vary core diameter active fibers. Photonics, 10, 147(2023).

[96] B Yang, H Zhang, P Wang, . 4 kW single mode narrow linewidth fiber laser achieved in single-end pumped fiber amplifier. High Power Laser and Particle Beams, 34, 041002(2022).

[97] Lingfa Zeng, Huan Yang, Xiaoming Xi, et al. Optimization and demonstration of 6 kW oscillating-amplifying integrated fiber laser employing spindle-shaped fiber to suppress SRS and TMI. Optics and Laser Technology, 159, 108903(2023).

[98] L Wang, H Zhang, P Wang, et al. Theoretical and experimental study of high-peak-power high-brightness quasi-CW fiber laser. IEEE Photonics Journal, 14, 1530206(2022).

[99] L Zeng, X Xi, H Zhang, et al. Demonstration of the reliability of a 5-kW-level oscillating–amplifying integrated fiber laser. Optics Letters, 46, 5778-5781(2021).

[100] Y Wen, P Wang, X Xi, . Laser diode directly backward pumped high-beam-quality 10-kW fiber laser. Acta Phys Sin, 71, 244202(2022).

[101] [101] Wang X, Xi X, Zhang H, et al. Manufacturing method manufacturing device of gain energy transmission integrated optical fiber prefm: China, CN112830673A[P]. 20210525.

[102] [102] Klein S, Giesberts M, Baer P, et al. Fiber Bragg gratings in active multimode XLMA fibers f highpower kWclass fiber lasers[C]Proc of SPIE, 2020, 11260.

[105] Q Shu, C Li, H Lin, . 2 kW class antireflection fiber laser with oscillator-amplifier integration. Chinese Journal of Lasers, 45, 0801004(2018).

[106] X Wang, H Zhang, B Yang, . High-powerytterbium-doped fiber laser oscillator: current situation and future developments. Chinese Journal of Lasers, 48, 0401004(2021).