[1] [1] Paschotta R, Nilsson J, Tropper A C, et al. Ytterbium-doped fiber amplifers［J］. IEEE Journal of Quantum Electronics, 1997, 33(7): 1049-1056.

[2] [2] Tünnermann A, Schreiber T, Rser F, et al. The renaissance and bright future of fibre lasers［J］. Journal of Physics B, 2005, 38: S681-S693.

[3] [3] Limpert J, Rser F, Klingebiel S, et al. The rising power of fiber lasers and amplifiers［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2007, 13(3): 537-545.

[4] [4] Dawson J W, Messerly M J, Beach R J, et al. Analysis of the scalability of diffraction-limited fiber lasers and amplifiers to high average power［J］. Optics Express, 2008, 16(17): 13240-13266.

[5] [5] Smith A V, Smith J J. Mode instability in high power fiber amplifiers［J］. Optics Express, 2011, 19(11): 10180-10192.

[6] [6] Eidam T, Wirth C, Jauregui C, et al. Experimental observation of the threshold-like onset of mode instabilities in high power fiber amplifiers［J］. Optics Express, 2011, 19(14): 13218-13224.

[7] [7] Bochove E. Theory of spectral beam combining of fiber lasers［J］. IEEE Journal of Quantum Electronics, 2002, 38(5): 432-445.

[8] [8] Augst S J, Goyal A K, Aggarwal R L, et al. Wavelength beam combining of ytterbium fiber lasers［J］. Optics Letters, 2003, 28(5): 331-333.

[9] [9] Liu A P, Mead R, Vatter T, et al. Spectral beam combining of high power fiber lasers［C］. SPIE, 2004, 5335: 81-88.

[10] [10] Fan T Y. Laser beam combining for high-power, high-radiance sources［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2005, 11(3): 567-577.

[11] [11] Augst S J, Ranka J K, Fan T Y, et al. Beam combining of ytterbium fiber amplifiers［J］. Journal of the Optical Society of America B, 2007, 24(8): 1707-1715.

[12] [12] Sprangle P, Ting A, Penano J, et al. Incoherent combining and atmospheric propagation of high-power fiber lasers for directed-energy applications［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2007, 45(2): 138-148.

[13] [13] Noordegraaf D, Maack M D, Skovgaard P M W, et al. All-fiber 7×1 signal combiner for incoherent laser beam combining［C］. SPIE, 2011, 7914: 79142L.

[14] [14] Swanson G J, Leger J R, Holz M. Aperture filling of phase-locked laser arrays［J］. Optics Letters, 1987, 12(4): 245-247.

[15] [15] He B, Lou Q, Zhou J, et al. High power coherent beam combination from two fiber lasers［J］. Optics Express, 2006, 14(7): 2721-2726.

[16] [16] Cheung E C, Ho J G, Goodno G D, et al. Diffractive-optics-based beam combination of a phase-locked fiber laser array［J］. Optics Letters, 2008, 33(4): 354-356.

[17] [17] Goodno G D, McNaught S J, Rothenberg J E, et al. Active phase and polarization locking of a 1.4 kW fiber amplifier［J］. Optics Letters, 2010, 35(10): 1542-1544.

[18] [18] Zhou P, Ma Y, Wang X L, et al. Coherent beam combination of three two-tone fiber amplifiers using stochastic parallel gradient descent algorithm［J］. Optics Letters, 2009, 34(19): 2939-2941.

[19] [19] Yu C X, August S J, Redmond S M, et al. Coherent combining of a 4 kW, eight-element fiber amplifier array［J］. Optics Letters, 2011, 36(14): 2686-2688.

[20] [20] Ma P, Tao R, Wang X, et al. Coherent polarization beam combination of four mode-locked fiber MOPAs in picosecond regime［J］. Optics Express, 2014, 22(4): 4123-4130.

[21] [21] Redmond S M, Ripin D J, Yu C X, et al. Diffractive coherent combining of a 2.5 kW fiber laser array into a 1.9 kW Gaussian beam［J］. Optics Letters, 2012, 37(14): 2832-2834.

[22] [22] Flores A, Dajani I, Holten R, et al. Multi-kilowatt diffractive coherent combining of pseudorandom-modulated fiber amplifiers［J］. Optical Engineering, 2016, 55(9): 096101.

[23] [23] Lhermite J, Desfarges-Berthelemot A, Kermene V, et al. Passive phase locking of an array of four fiber amplifiers by an all-optical feedback loop［J］. Optics Letters, 2007, 32(13): 1842-1844.

[24] [24] Liu H, He B, Zhou J, et al. Coherent beam combination of two nanosecond fiber amplifiers by all-optical feedback loop［J］. Optics Letters, 2012, 37(18): 3885-3887.

[25] [25] Yang Y, Hu M, He B, et al. Passive coherent beam combining of four Yb-doped fiber amplifier chains with injection-locked seed source［J］. Optics Letters, 2013, 38(6): 854-856.

[26] [26] Yang Y, Liu H, Zheng Y, et al. Dammann-grating-based passive phase locking by an all-optical feedback loop［J］. Optics Letters, 2014, 39(3): 708-710.

[27] [27] Klingebiel S, Rser F, Orta B, et al. Spectral beam combining of Yb-doped fiber lasers with high efficiency［J］. Journal of the Optical Society of America B, 2007, 24(8): 1716-1720.

[28] [28] Loftus T H, Thomas A M, Hoffman P R, et al. Spectrally beam-combined fiber lasers for high-average-power applications［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2007, 13(3): 487-497.

[29] [29] Loftus T H, Liu A P, Hoffman P R, et al. 258 W of spectrally beam combined power with near-diffraction limited beam quality［C］. SPIE, 2006, 6102: 61020S.

[30] [30] Schreiber T, Wirth C, Schmidt O, et al. Incoherent beam combining of continuous-wave and pulsed Yb-doped fiber amplifiers［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2009, 15(2): 354-360.

[31] [31] Cook C C, Fan T Y. Spectral beam combining of Yb-doped fiber lasers in an external cavity［C］. Advanced Solid State Lasers, 1999, 26: 163-166.

[32] [32] Ciapurin I V, Glebov L B, Glebova L N, et al. Incoherent combining of 100-W Yb-fiber laser beams by PTR Bragg grating［C］. SPIE, 2003, 4974: 209-219.

[33] [33] Andrusyak O, Smirnov V, Venus G, et al. Spectral combining and coherent coupling of lasers by volume Bragg gratings［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2009, 15(2): 344-353.

[34] [34] Loftus T H, Liu A P, Hoffman P R, et al. 522 W average power, spectrally beam-combined fiber laser with near-diffraction-limited beam quality［J］. Optics Letters, 2007, 32(4): 349-351.

[35] [35] Sevian A, Andrusyak O, Ciapurin I, et al. Efficient power scaling of laser radiation by spectral beam combining［J］. Optics Letters, 2008, 33(4): 384-386.

[36] [36] Schmidt O, Wirth C, Tsybin I. Average power of 1.1 kW from spectrally combined, fiber-amplified, nanosecond-pulsed sources［J］. Optics Letters, 2009, 34(10): 1567-1569.

[37] [37] Wirth C, Schmidt O, Tsybin I, et al. 2 kW incoherent beam combining of four narrow-linewidth photonic crystal fiber amplifiers［J］. Optics Express, 2009, 17(3): 1178-1183.

[38] [38] Schmidt O, Wirth C, Nodop D, et al. Spectral beam combination of fiber amplified ns-pulses by means of interference filters［J］. Optics Express, 2009, 17(25): 22974-22982.

[39] [39] Madasamy P, Jander D R, Brooks C D, et al. Dual-grating spectral beam combination of high-power fiber lasers［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2009, 15(2): 337-343.

[40] [40] Schmidt O, Andersen T V, Limpert J, et al. 187 W, 3.7 mJ from spectrally combined pulsed 2 ns fiber amplifiers［J］. Optics Letters, 2009, 34(3): 226-228.

[41] [41] Wirth C, Schmidt O, Tsybin I, et al. High average power spectral beam combining of four fiber amplifiers to 8.2 kW［J］. Optics Letters, 2011, 36(16): 3118-3120.

[42] [42] Ott D, Divliansky I, Anderson B, et al. Scaling the spectral beam combining channels in a multiplexed volume Bragg grating［J］. Optics Express, 2013, 21(24): 29620-29627.

[43] [43] Honea E, Afzal R S, Savage-Leuchs M, et al. Spectrally beam combined fiber lasers for high power, efficiency and brightness［C］. SPIE, 2013, 8601: 860115.

[44] [44] Drachenberg D R, Andrusyak O, Venus G, et al. Thermal tuning of volume Bragg gratings for spectral beam combining of high-power fiber lasers［J］. Applied Optics, 2014, 53(6): 1242-1246.

[45] [45] Honea E, Afzal R S, Savage-Leuchs M, et al. Advances in fiber laser spectral beam combining for power scaling［C］. SPIE, 2015, 9730: 97300Y.

[46] [46] Liang Xiaobao, Chen Liangming, Li Chao, et al. High average power spectral beam combining employing volume Bragg gratings［J］. High Power Laser and Particle beams, 2015, 27(7): 071012.

[47] [47] Ma Yi, Yan Hong, Tian Fei, et al. Common aperture spectral beam combination of fiber lasers with 5 kW power high-efficiency and high-quality output［J］. High Power Laser and Particle beams, 2015, 27(4): 040101.

[48] [48] Ma Yi, Yan Hong, Peng Wanjing, et al. 9.6 kW common aperture spectral beam combination system based on multi-channel narrow-linewidth fiber lasers［J］. Chinese J Lasers, 2016, 43(9): 0901009.

[49] [49] Zheng Y, Yang Y F, Wang J H, et al. 10.8 kW spectral beam combination of eight all-fiber superfluorescent sources and their dispersion compensation［J］. Optics Express, 2016, 24(11): 12063-12071.

[50] [50] Daneu V, Sanchez A, Fan T Y, et al. Spectral beam combining of a broad-stripe diode laser array in an external cavity［J］. Optics Letters, 2000, 25(6): 405-407.

[51] [51] Chann B, Huang R K, Missaggia L J, et al. Near-diffraction-limited diode laser arrays by wavelength beam combining［J］. Optics Letters, 2005, 30(16): 2104-2106.

[52] [52] Gopinath J T, Chann B, Fan T Y, et al. 1450-nm high-brightness wavelength-beam combined diode laser array［J］. Optics Express, 2008, 16(13): 9405-9410.

[53] [53] Dajani I, Zeringur C, Lu C, et al. Stimulated Brillouin scattering suppression through laser gain competition: Scalability to high power［J］. Optics Letters, 2010, 35(18): 3114-3116.

[54] [54] Dajani I, Zeringue C, Shay T M. Investigation of nonlinear effects in multitone-driven narrow-linewidth high-power amplifiers［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2009, 15(2): 406-414.

[55] [55] Mermelstein M D, Andrejco M J, Fini J, et al. SBS suppression and acoustic management for high-power narrow-linewidth fiber lasers and amplifiers［C］. SPIE, 2010, 7580: 75801G.

[56] [56] Suradeepa V R. Stimulated Brillouin scattering thresholds in optical fibers for lasers linewidth broadened with noise［J］. Optics Express, 2013, 21(4): 4677-4687.

[57] [57] Gray S, Liu A, Walton D T, et al. 502 Watt, single transverse mode, narrow linewidth, bidirectionally pumped Yb-doped fiber amplifier［J］. Optics Express, 2007, 15(25): 17044-17050.

[58] [58] Jeong Y, Nilsson J, Sahu J K, et al. Power scaling of single frequency Ytterbium-doped fiber master oscillator power amplifier sources up to 500 W［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2007, 13(3): 546-551.

[59] [59] Goodno G D, Book L D, Rothenberg J E. Low-phase-noise, single-frequency, single-mode 608 W thulium fiber amplifier［J］. Optics Letters, 2009, 34(8): 1204-1206.

[60] [60] Khitrov V, Farley K, Leveille R, et al. kW level narrow linewidth Yb fiber amplifiers for beam combining［C］. SPIE, 2010, 7686: 76860A.

[61] [61] Engin D, Lu W, Akbulut M, et al. 1 kW cw Yb-fiber-amplifier with ＜0.5 GHz linewidth and near diffraction limited beam-quality, for coherent combining application［C］. SPIE, 2011, 7914: 791407.

[62] [62] Robin C, Dajani I, Pulford B. Modal instability-suppressing, single-frequency photonic crystal fiber amplifier with 811 W output power［J］. Optics Letters, 2014, 39(3): 666-669.

[63] [63] Flores A, Robin C, Lanari A, et al. Pseudo-random binary sequence phase modulation for narrow linewidth, kilowatt, monolithic fiber amplifiers［J］. Optics Express, 2014, 22(15): 17735-17744.

[64] [64] Nold J, Strecker M, Liem A, et al. Narrow linewidth single mode fiber amplifier with 2.3 kW average power［J］. Optics Express, 2016, 24(6): 6011-6020.

[65] [65] Yagodkin R, Platonov N, Yusim A, et al. ＞1.5 kW narrow linewidth CW diffraction-limited fiber amplifier with 40 nm bandwidth［C］. SPIE, 2016, 9728: 972807.

[66] [66] Naderi N A, Flores A, Anderson B M, et al. Beam combinable, kilowatt, all-fiber amplifier based on phase-modulated laser gain competition［J］. Optics Letters, 2016, 41(17): 3964-3967.

[67] [67] Naderi N A, Dajani I, Flores A. High-efficiency, kilowatt 1034 nm all-fiber amplifier operating at 11 pm linewidth［J］. Optics Letters, 2016, 41(5): 1018-1021.

[68] [68] Beier F, Hupel C, Nold J, et al. Narrow linewidth, single mode 3 kW average power from a directly diode pumped ytterbium-doped low NA fiber amplifier［J］. Optics Express, 2016, 24(6): 6011-6020.

[69] [69] Ma P F, Tao R M, Su R T, et al. 1.89 kW all-fiberized and polarization-maintained amplifiers with narrow linewidth and near-diffraction-limited beam quality［J］. Optics Express, 2016, 24(4): 4187-4195.

[70] [70] Liu G B, Yang Y F, Wang J H, et al. Stimulated Brillouin scattering enhancement factor improvement in 11.6 GHz linewidth, 1.5 kW Yb-doped fiber amplifier［J］. Chinese Physics Letters, 2016, 33(7): 074207.

[72] [72] von Elm R, Marois C. Beam-combiner for fiber-delivered laser-beams of different wavelengths: US8599487［P］. 2013-12-03.

[73] [73] Chang Y L, Kim B K, Sang S H, et al. Multi beam laser apparatus: US7991037［P］. 2011-08-02.

[74] [74] Gold R S, Jachimowicz K E. Beam combining/splitter cube prism for color polarization: US5067799［P］. 1991-11-26.

[75] [75] Pickering R D. Beam combining prism: US2983183［P］. 1961-05-09.

[76] [76] Perry M D, Boyd R D, Britten J A, et al. High-efficiency multilayer dielectric diffraction gratings［J］. Optics Letters, 1995, 20(8): 940-942.

[77] [77] Shore B W, Perry M D, Britten J A, et al. Design of high-efficiency dielectric reflection gratings［J］. Journal of the Optical Society of America A, 1997, 14(5): 1124-1136.