[1] 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).

[2] A V Smith, J J Smith. Mode instability in high power fiber amplifiers. Optics Express, 19, 10180-10192(2011).

[3] T Eidam, C Wirth, C Jauregui, et al. Experimental observations of the threshold-like onset of mode instabilities in high power fiber amplifiers. Optics Express, 19, 13218-13224(2011).

[4] Y Zheng, Y F Yang, X Zhao, et al. Research progress on spectral beam combining technology of high-power fiber lasers. Chinese Journal of Lasers, 44, 0201002(2017).

[5] T Y Fan. Laser beam combining for high-power, high-radiance sources. IEEE Journal of Selected Topics in Quantum Electronics, 11, 567-577(2005).

[6] S J Augst, J K Ranka, T Y Fan, et al. Beam combining of ytterbium fiber amplifiers (Invited). Journal of The Optical Society of America B-optical Physics, 24, 1707-1715(2007).

[7] [7] Strecker M, Plötner M, Stutzki F, et al. Highly efficient dualgrating 3channel spectral beam combining of narrowlinewidth monolithic cw Ybdoped fiber amplifiers up to 5.5 kW[C]Proc SPIE 10897, Fiber Lasers XVI: Technology Systems, 2019, 10897: 108970E.