[1] Snitzer E. Proposed fiber cavities for optical masers[J]. J Appl Phys, 32, 36-39(1961).

[2] Koester C J, Snitzer E. Amplification in a fiber laser[J]. Appl Opt, 3, 1182-1186(1964).

[3] Stone J, Burrus C A. Neodymium-doped silica lasers in end-pumped fiber geometry[J]. Appl Phys Lett, 23, 388-389(1973).

[4] [4] Snitzer E, Po H, Hakimi F, et al. Doubleclad offset ce Nd fiber laser[C]Optical Fiber Sens Conference. 1989, PD5: 533536.

[5] Shi W, Fang Q, Zhu X. Fiber lasers and their applications[J]. Appl Opt, 53, 6554(2014).

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

[8] Zervas M N, Codemard C A. High power fiber lasers: A review[J]. IEEE J Sel Top Quant, 20, 219-241(2014).

[9] [9] Shiner B. The impact of fiber laser technology on the wld wide material processing market[C]Conference on Lasers ElectroOptics. 2013: AF2J.

[10] [10] IPG Photonics. IPG set to ship 100 kW laser[DBOL]. http:optics.gnews31044.

[11] Kumar S C, Samanta G K, Ebrahim-Zadeh M. High-power, single-frequency, continuous-wave second-harmonic-generation of ytterbium fiber laser in PPKTP and MgO:sPPLT[J]. Opt Express, 17, 13711-13726(2009).

[12] Henderson A, Stafford R. Low threshold, singly-resonant CW OPO pumped by an all-fiber pump source[J]. Opt Express, 14, 767(2006).

[13] Abbott B P. Observation of gravitational waves from a binary black hole merger[J]. Phys Rev Lett, 116, 061102(2016).

[14] Steinke M, Tunnermann H, Kuhn V. Single-frequency fiber amplifiers for next-generation gravitational wave detectors[J]. IEEE J Sel Top Quant, 24, 3100613(2018).

[15] Buikema A, Jose F, Augst S J. Narrow-linewidth fiber amplifier for gravitational-wave detectors[J]. Opt Lett, 44, 3833(2019).

[16] Cariou J, Augere B, Valla M. Laser source requirements for coherent lidars based on fiber technology[J]. Comptes Rendus Physique, 7, 213-223(2006).

[17] Diaz R, Chan S, Liu J. Lidar detection using a dual-frequency source[J]. Opt Lett, 31, 3600(2006).

[18] Fan T Y. Laser beam combining for high-power, high-radiance sources[J]. IEEE J Sel Top Quant, 11, 567-577(2005).

[19] Liu Z, Ma P, Su R. High-power coherent beam polarization combination of fiber lasers: progress and prospect[J]. Journal of the Optical Society of America B, 34, A7(2017).

[20] Loftus T H, Thomas A M, Hoffman P R. Spectrally beam-combined fiber lasers for high-average-power applications[J]. IEEE J Sel Top Quant, 13, 487-497(2007).

[22] Wang Y, Ke W, Peng W. 3 kW, 0.2 nm narrow linewidth linearly polarized all-fiber laser based on a compact MOPA structure[J]. Laser Phys Lett, 17, 075101(2020).

[23] Yu C X, Shatrovoy O, Fan T Y. Diode-pumped narrow linewidth multi-kilowatt metalized Yb fiber amplifier[J]. Opt Lett, 41, 5202(2016).

[24] Ma P, Xiao H, Meng D. High power all-fiberized and narrow-bandwidth MOPA system by tandem pumping strategy for thermally induced mode instability suppression[J]. High Power Laser Science and Engineering, 6, e57(2018).

[25] [25] Qi Y, Yang Y, Shen H, et al. 2.7 kW CW narrow linewidth Ybdoped allfiber amplifiers f beam combining application[C]Advanced SolidState Lasers. 2017: ATu3A.1.

[26] Beier F, Moller F, Sattler B. Experimental investigations on the TMI thresholds of low-NA Yb-doped single-mode fibers[J]. Opt Lett, 43, 1291-1294(2018).

[27] [27] Platonov N, Yagodkin R, De La Cruz J, et al. Up to 2.5 kW on nonPM fiber 2.0 kW linear polarized on PM fiber narrow linewidth CW diffractionlimited fiber amplifiers in allfiber fmat[C]Proc of SPIE. 2018: 105120E.

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

[29] Kobyakov A, Sauer M, Chowdhury D. Stimulated Brillouin scattering in optical fibers[J]. Adv Opt Photonics, 2, 1(2010).

[30] Eidam T, Wirth C, Jauregui C. Experimental observations of the threshold-like onset of mode instabilities in high power fiber amplifiers[J]. Opt Express, 19, 13218(2011).

[31] Jauregui C, Stihler C, Limpert J. Transverse mode instability[J]. Adv Opt Photonics, 12, 429(2020).

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

[33] Zhu S, Li J, Li L. Mode instabilities in Yb:YAG crystalline fiber amplifiers[J]. Opt Express, 27, 35065(2019).

[34] Tao R, Wang X, Zhou P. Comprehensive theoretical study of mode instability in high-power fiber lasers by employing a universal model and its implications[J]. IEEE J Sel Top Quant, 24, 0903319(2018).

[35] Fu S, Shi W, Feng Y. Review of recent progress on single-frequency fiber lasers[J]. Journal of the Optical Society of America B, 34, A49(2017).

[37] Jiang Man, Zhou Pu, Gu Xijia. Ultralong π-phase shift fiber Bragg grating empowered single longitudinal mode DFB phosphate fiber laser with low-threshold and high-efficiency[J]. Scientific Reports, 8, 13131(2018).

[38] Babin S A, Churkin D V, Ismagulov A E. Single frequency single polarization DFB fiber laser[J]. Laser Phys Lett, 4, 428-432(2007).

[39] [39] Geng J, Wu J, Jiang S. Efficient singlefrequency thulium doped fiber laser near 2µm[C]Advanced SolidState Lasers. 2007: WE4.

[40] Schülzgen A, Li L, Nguyen D. Distributed feedback fiber laser pumped by multimode laser diodes[J]. Opt Lett, 33, 614(2008).

[41] Geng J, Wang Q, Luo T. Single-frequency narrow-linewidth Tm-doped fiber laser using silicate glass fiber[J]. Opt Lett, 34, 3493(2009).

[42] Zhu X, Shi W, Zong J. 976 nm single-frequency distributed Bragg reflector fiber laser[J]. Opt Lett, 37, 4167(2012).

[43] Liu Z, Xie Y, Cong Z. 110 mW single-frequency Yb:YAG crystal-derived silica fiber laser at 1064 nm[J]. Opt Lett, 44, 4307-4310(2019).

[44] Wang Y, Wu J, Zhao Q. Single-frequency DBR Nd-doped fiber laser at 1120 nm with a narrow linewidth and low threshold[J]. Opt Lett, 45, 2263(2020).

[45] Schülzgen A, Li L, Temyanko V L. Single-frequency fiber oscillator with watt-level output power using photonic crystal phosphate glass fiber[J]. Opt Express, 14, 7087(2006).

[46] Guan X, Yang C, Qiao T. High-efficiency sub-watt in-band-pumped single-frequency DBR Tm³⁺-doped germanate fiber laser at 1950 nm[J]. Opt Express, 26, 6817(2018).

[47] Slimen F B, Chen S, Lousteau J. Highly efficient Tm³⁺-doped germanate large mode area single mode fiber laser[J]. Opt Mater Express, 9, 4115(2019).

[48] Park N, Dawson J W, Vahala K J. All fiber, low threshold, widely tunable single-frequency, erbium-doped fiber ring laser with a tandem fiber Fabry–Perot filter[J]. Appl Phys Lett, 59, 2369-2371(1991).

[49] Gloag A, Langford N, Mccallion K. Continuously tunable single-frequency erbium ring fiber laser[J]. Journal of the Optical Society of America B, 13, 921(1996).

[50] Zhang X, Zhu N H, Xie L. A stabilized and tunable single-frequency erbium-doped fiber ring laser employing external injection locking[J]. J Lightwave Technol, 25, 1027-1033(2007).

[51] Cheng X P, Shum P, Tse C H. Single-longitudinal-mode erbium-doped fiber ring laser based on high finesse fiber Bragg grating Fabry—Perot etalon[J]. IEEE Photonic Tech L, 20, 976-978(2008).

[52] Yin T, Song Y, Jiang X. 400 mW narrow linewidth single-frequency fiber ring cavity laser in 2 um waveband[J]. Opt Express, 27, 15794(2019).

[53] Xu S, Yang Z, Zhang W. 400 mW ultrashort cavity low-noise single-frequency Yb⁽³⁾⁽⁺⁾-doped phosphate fiber laser[J]. Opt Lett, 36, 3708-3710(2011).

[54] Hofmann P, Voigtlander C, Nolte S. 550-mW output power from a narrow linewidth all-phosphate fiber laser[J]. J Lightwave Technol, 31, 756-760(2013).

[55] Kurkov A S. Oscillation spectral range of Yb-doped fiber lasers[J]. Laser Phys Lett, 4, 93-102(2007).

[56] Zhou P, Wang X, Xiao H. Review on recent progress on yb doped fiber laser in a variety of oscillation spectral ranges 1[J]. Laser Phys, 22, 823-831(2012).

[57] [57] Kaneda Y, Spiegelberg C, Geng J, et al. 200mW, narrowlinewidth 1064.2nm Ybdoped fiber laser[C]Conference on Lasers ElectroOptics. 2004, CThO3, 12.

[58] Mo S, Xu S, Huang X. A 1014 nm linearly polarized low noise narrow-linewidth single-frequency fiber laser[J]. Opt Express, 21, 12419(2013).

[59] Xu S, Li C, Zhang W. Low noise single-frequency single-polarization ytterbium-doped phosphate fiber laser at 1083 nm[J]. Opt Lett, 38, 501(2013).

[60] Yang C, Zhao Q, Feng Z. 1120 nm kHz-linewidth single-polarization single-frequency Yb-doped phosphate fiber laser[J]. Opt Express, 24, 29794(2016).

[61] Pan Zhengqing, Cai Haiwen, Meng Li. Single-frequency phosphate glass fiber laser with 100-mW output power at 1535 nm and its polarization characteristics[J]. Chinese Optics Letters, 8, 52-54(2010).

[62] Xu S H, Yang Z M, Liu T. An efficient compact 300 mW narrow-linewidth single frequency fiber laser at 1.5 mm[J]. Opt Express, 18, 1249-1254(2010).

[63] Fu S, Shi W, Sheng Q. Compact hundred-mW 2 μm single-frequencythulium-doped silica fiber laser[J]. IEEE Photo Tech Lett, 29, 853-856(2017).

[64] Spiegelberg C, Geng J, Hu Y. Low-noise narrow-linewidth fiber laser at 1550 nm (June 2003)[J]. J Lightwave Technol, 22, 57-62(2004).

[65] Qiu T, Suzuki S, Schülzgen A. Generation of Watt-level single-longitudinal-mode output from cladding-pumped short fiber lasers[J]. Opt Lett, 30, 2748(2005).

[66] Polynkin P, Polynkin A, Mansuripur M. Single-frequency laser oscillator with watts-level output power at 1.5 microm by use of a twisted-mode technique[J]. Opt Lett, 30, 2745-2747(2005).

[67] Ball G A, Holton C E, Hull-Allen G. 60 mW 1.5 μm single-frequency low-noise fiber laser MOPA[J]. IEEE Photonic Tech L, 6, 192-194(1994).

[68] Jeong Y, Nilsson J, Sahu J K. Single-frequency, single-mode, plane-polarized ytterbium-doped fiber master oscillator power amplifier source with 264 W of output power[J]. Opt Lett, 30, 459(2005).

[69] Jeong Y, Nilsson J, Sahu J K. Power scaling of single-frequency ytterbium-doped fiber master-oscillator power-amplifier sources up to 500 W[J]. IEEE J Sel Top Quant, 13, 546-551(2007).

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

[71] [71] Zhu C, Hu I, Ma X, et al. Singlefrequency singletransverse mode Ybdoped CCC fiber MOPA with robust polarization SBSfree 511W output[C]. OSAASSP, 2011, AMC5, 13.

[72] [72] Robin C, Dajani I, Chiragh F. Experimental studies of segmented acoustically tailed photonic crystal fiber amplifier with 494 W singlefrequency output[C]Proc of SPIE. 2011, 79140B.

[73] Robin C, Dajani I, Pulford B. Modal instability-suppressing, single-frequency photonic crystal fiber amplifier with 811 W output power[J]. Opt Lett, 39, 666(2014).

[74] [74] Mermelstein M D, Brar K, rejco M J, et al. Allfiber 194 W singlefrequency singlemode Ybdoped masteroscillat poweramplifier[C]Proc of SPIE. 2008: 68730L.

[75] Theeg T, Sayinc H, Neumann J. All-fiber counter-propagation pumped single frequency amplifier stage with 300-W output power[J]. IEEE Photonic Tech L, 24, 1864-1867(2012).

[76] Ma P, Zhou P, Ma Y. Single-frequency 332 W, linearly polarized Yb-doped all-fiber amplifier with near diffraction-limited beam quality[J]. Appl Opt, 52, 4854(2013).

[77] Zhang L, Cui S, Liu C. 170 W, single-frequency, single-mode, linearly-polarized, Yb-doped all-fiber amplifier[J]. Opt Express, 21, 5456-5462(2013).

[78] Huang L, Wu H, Li R. 414 W near-diffraction-limited all-fiberized single-frequency polarization-maintained fiber amplifier[J]. Opt Lett, 42, 1-4(2017).

[80] Zeringue C, Vergien C, Dajani I. Pump-limited, 203 W, single-frequency monolithic fiber amplifier based on laser gain competition[J]. Opt Lett, 36, 618-620(2011).

[81] Wang X L, Zhou P, Xiao H. 310 W single-frequency all-fiber laser in master oscillator power amplification configuration[J]. Laser Phys Lett, 9, 591-595(2012).

[82] Wellmann F, Steinke M, Meylahn F. High power, single-frequency, monolithic fiber amplifier for the next generation of gravitational wave detectors[J]. Opt Express, 27, 28523(2019).

[83] Dixneuf C, Guiraud G, Bardin Y. Ultra-low intensity noise, all fiber 365 W linearly polarized single frequency laser at 1064 nm[J]. Opt Express, 28, 10960(2020).

[84] [84] Creeden D, Pretius H, Limongelli J, et al. Single frequency 1560 nm Er: Yb fiber amplifier with 207W output power 50.5% slope efficiency[C]Proc of SPIE. 2015: 97282L.

[85] De Varona O, Fittkau W, Booker P. Single-frequency fiber amplifier at 1.5 microm with 100 W in the linearly-polarized TEM₀₀ mode for next-generation gravitational wave detectors[J]. Opt Express, 25, 24880-24892(2017).

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

[87] Wang X, Zhou P, Wang X. 102 W monolithic single frequency Tm-doped fiber MOPA[J]. Opt Express, 21, 32386(2013).

[88] Wang X, Jin X, Wu W. 310-W single frequency Tm-doped all-fiber MOPA[J]. IEEE Photonic Tech L, 27, 677-680(2015).

[89] Liu J, Shi H, Liu K. 210 W single-frequency, single-polarization, thulium-doped all-fiber MOPA[J]. Opt Express, 22, 13572(2014).

[90] Guan X, Yang C, Gu Q. 55 W kilohertz-linewidth core- and in-band-pumped linearly polarized single-frequency fiber laser at 1950 nm[J]. Opt Lett, 45, 2343-2346(2020).

[91] Tokita S, Murakami M, Shimizu S. Liquid-cooled 24 W mid-infrared Er:ZBLAN fiber laser[J]. Opt Lett, 34, 3062(2009).

[92] Mollaee M, Zhu X, Zong J. Single-frequency blue laser fiber amplifier[J]. Opt Lett, 43, 423(2018).

[93] Zhu X, Zong J, Miller A. Single-frequency Ho⁽³⁺⁾-doped ZBLAN fiber laser at 1200 nm[J]. Opt Lett, 37, 4185-4187(2012).

[94] Hudson D D, Williams R J, Withford M J. Single-frequency fiber laser operating at 2.9 μm[J]. Opt Lett, 38, 2388-2390(2013).

[95] Shaw L B, Cole B, Thielen P A. Mid-wave IR and long-wave IR laser potential of rare-earth doped chalcogenide glass fiber[J]. IEEE J Quantum Elect, 37, 1127-1137(2001).

[96] Quimby R S, Shaw L B, Sanghera J S. Modeling of cascade lasing in Dy: chalcogenide glass fiber laser with efficient output at 4.5 mm[J]. IEEE Photonic Tech L, 20, 123-125(2008).

[97] Loranger S, Karpov V, Schinn G W. Single-frequency low-threshold linearly polarized DFB Raman fiber lasers[J]. Opt Lett, 42, 3864(2017).

[98] Jiang S, Guo C, Che K. Visible Raman and Brillouin lasers from a microresonator/ZBLAN-fiber hybrid system[J]. Photonics Res, 7, 566(2019).

[99] Peng C, Liang X, Liu R. High-precision active synchronization control of high-power, tiled-aperture coherent beam combining[J]. Opt Lett, 42, 3960(2017).

[100] Muller M, Klenke A, Steinkopff A. 3.5 kW coherently combined ultrafast fiber laser[J]. Opt Lett, 43, 6037-6040(2018).

[101] Loftus T H, Liu A, Hoffman P R. 522 W average power, spectrally beam-combined fiber laser with near-diffraction-limited beam quality[J]. Opt Lett, 32, 349-351(2007).

[102] Schmidt O, Wirth C, Nodop D. Spectral beam combination of fiber amplified ns-pulses by means of interference filters[J]. Opt Express, 17, 22974-22982(2009).

[103] Wirth C, Schmidt O, Tsybin I. High average power spectral beam combining of four fiber amplifiers to 8.2 kW[J]. Opt Lett, 36, 3118-3120(2011).

[104] White J O, Harfouche M, Edgecumbe J. 1.6 kW Yb fiber amplifier using chirped seed amplification for stimulated Brillouin scattering suppression[J]. Appl Opt, 56, B116-B122(2017).

[105] Lee J, Lee K H, Jeong H. 2.05 kW all-fiber high-beam-quality fiber amplifier with stimulated Brillouin scattering suppression incorporating a narrow-linewidth fiber-Bragg-grating-stabilized laser diode seed source[J]. Appl Opt, 58, 6251-6256(2019).

[106] Xu Y, Fang Q, Qin Y. 2 kW narrow spectral width monolithic continuous wave in a near-diffraction-limited fiber laser[J]. Appl Opt, 54, 9419(2015).

[107] Huang Z, Liang X, Li C. Spectral broadening in high-power Yb-doped fiber lasers employing narrow-linewidth multilongitudinal-mode oscillators[J]. Appl Opt, 55, 297(2016).

[108] Wang Y, Feng Y, Wang X. 6.5 GHz linearly polarized kilowatt fiber amplifier based on active polarization control[J]. Appl Opt, 56, 2760-2765(2017).

[111] Yan P, Huang Y, Sun J. 3.1 kW monolithic MOPA configuration fibre laser bidirectionally pumped by non-wavelength-stabilized laser diodes[J]. Laser Phys Lett, 14, 080001(2017).

[112] Huang Y, Yan P, Wang Z. 2.19 kW narrow linewidth FBG-based MOPA configuration fiber laser[J]. Opt Express, 27, 3136(2019).

[113] [113] Shi W, Fang Q, Fan J, et al. High power monolithic linearly polarized narrow linewidth single mode fiber laser at 1064 nm[C]Conference on Lasers ElectroOptics Pacific Rim. 2015.

[114] Jiang M, Ma P, Huang L. kW-level, narrow-linewidth linearly polarized fiber laser with excellent beam quality through compact one-stage amplification scheme[J]. High Power Laser Science and Engineering, 5, e30(2017).

[115] Ma P, Tao R, Wang X. High-power narrow-band and polarization-maintained all fiber superfluorescent source[J]. IEEE Photonic Tech L, 27, 879-882(2015).

[116] Xu J, Liu W, Leng J. Power scaling of narrowband high-power all-fiber superfluorescent fiber source to 1.87 kW[J]. Opt Lett, 40, 2973-2976(2015).

[117] Xu Jiangming, Huang Long, Jiang Man et al. Near-diffraction-limited linearly polarized narrow-linewidth random fiber laser with record kilowatt output[J]. Photonics Research, 5, 350-354(2017).

[119] [119] Qi Y, Ming Lei, Liu C, et al. 1.75 kW CW narrow linewidth Ybdoped allfiberamplifiers f beam combining application[C]Conference on Lasers ElectroOptics. 2015: ATu4M.

[121] [121] Engin D, Lu W, Akbulut M, et al. 1 kW cw Ybfiberamplifier with

[122] Ma P, Tao R, Su R. 1.89 kW all-fiberized and polarization-maintained amplifiers with narrow linewidth and near-diffraction-limited beam quality[J]. Opt Express, 24, 4187(2016).

[123] Su R, Tao R, Wang X. 2.43 kW narrow linewidth linearly polarized all-fiber amplifier based on mode instability suppression[J]. Laser Phys Lett, 14, 085102(2017).

[124] Li T, Zha C, Sun Y. 3.5 kW bidirectionally pumped narrow-linewidth fiber amplifier seeded by white-noise-source phase-modulated laser[J]. Laser Phys, 28, 105101(2018).

[126] Lin H, Tao R, Li C. 3.7 kW monolithic narrow linewidth single mode fiber laser through simultaneously suppressing nonlinear effects and mode instability[J]. Opt Express, 27, 9716(2019).

[127] Shen H, Lou Q, Quan Z. Narrow-linewidth all-fiber amplifier with up to 3.01 kW output power based on commercial 20/400 μm active fiber and counterpumped configuration[J]. Appl Opt, 58, 3053-3058(2019).

[128] Liu Meizhong, Yang Yifeng, Shen Hui. 1.27 kW, 2.2 GHz pseudo-random binary sequence phase modulated fiber amplifier with Brillouin gain-spectrum overlap[J]. Scientific Reports, 10, 629(2020).

[129] Flores A, Robin C, Lanari A. Pseudo-random binary sequence phase modulation for narrow linewidth, kilowatt, monolithic fiber amplifiers[J]. Opt Express, 22, 17735(2014).

[130] [130] Dajani I, Fles A, Holten R, et al. Multikilowatt power scaling coherent beam combining of narrowlinewidth fiber lasers[C]Proc of SPIE. 2015: 972801.

[131] Naderi N A, Dajani I, Flores A. High-efficiency, kilowatt 1034 nm all-fiber amplifier operating at 11pm linewidth[J]. Opt Lett, 41, 1018(2016).

[132] Naderi N A, Flores A, Anderson B M. Beam combinable, kilowatt, all-fiber amplifier based on phase-modulated laser gain competition[J]. Opt Lett, 41, 3964(2016).

[133] Anderson B M, Flores A, Dajani I. Filtered pseudo random modulated fiber amplifier with enhanced coherence and nonlinear suppression[J]. Opt Express, 25, 17671(2017).

[134] [134] Kanskar M, Zhang J, Koponen J, et al. Narrowb transversemodalinstability (TMI)free Ybdoped fiber amplifiers f directed energy applications[C]Proc SPIE. 2018: 15120F.

[135] [135] Lim W Y W, Seah K W, Seah C P, et al. Wavelength flexible, kWlevel narrow linewidth fibre laser based on 7GHz PRBS phase modulation[C]Proc of SPIE. 2020: 1126006.

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

[137] Beier F, Hupel C, Kuhn S. Single mode 4.3 kW output power from a diode-pumped Yb-doped fiber amplifier[J]. Opt Express, 25, 14892(2017).

[138] [138] Chu Q, Shi Y, Wen J, et al. 2.5 kW narrow linewidth fiber amplifier with white noise signal phase modulated seed[C]Conference on Lasers ElectroOptics. 2018: W1A.

[139] Chang Z, Wang Y, Sun Y. 1.5 kW polarization-maintained Yb-doped amplifier with 13 GHz linewidth by suppressing the self-pulsing and stimulated Brillouin scattering[J]. Appl Opt, 58, 6419-6425(2019).

[140] Meng D, Lai W, He X. Kilowatt-level, mode-instability-free, all-fiber and polarization-maintained amplifier with spectral linewidth of 1.8 GHz[J]. Laser Phys, 29, 035103(2019).

[141] Anderson B, Flores A, Holten R. Comparison of phase modulation schemes for coherently combined fiber amplifiers[J]. Opt Express, 23, 27046(2015).

[142] Kablukov S I, Zlobina E A, Podivilov E V. Output spectrum of Yb-doped fiber lasers[J]. Opt Lett, 37, 2508(2012).

[143] Liu W, Ma P, Lü H. General analysis of SRS-limited high-power fiber lasers and design strategy[J]. Opt Express, 24, 26715-26721(2016).

[144] Liu W, Ma P, Lü H. Investigation of stimulated Raman scattering effect in high-power fiber amplifiers seeded by narrow-band filtered superfluorescent source[J]. Opt Express, 24, 8708(2016).

[145] Harish A V, Nilsson J. Optimization of phase modulation with arbitrary waveform generators for optical spectral control and suppression of stimulated Brillouin scattering[J]. Opt Express, 23, 6988(2015).

[146] Harish A V, Nilsson J. Optimization of phase modulation formats for suppression of stimulated brillouin scattering in optical fibers[J]. IEEE J Sel Top Quant, 24, 1-10(2018).

[147] White J O, Young J T, Wei C. Seeding fiber amplifiers with piecewise parabolic phase modulation for high SBS thresholds and compact spectra[J]. Opt Express, 27, 2962(2019).

[148] Goodno G D, Rothenberg J E. Suppression of stimulated Brillouin scattering in high power fibers using nonlinear phase demodulation[J]. Opt Express, 27, 13129(2019).

[149] [149] Stihler C, Jauregui C, Otto H, et al. Controlling mode instabilities at 628 W average output power in an Ybdoped rodtype fiber amplifier by active modulation of the pump power[C]Proc of SPIE. 2017: 100830P.

[150] Tao Rumao, Wang Xiaolin, Zhou Pu. Seed power dependence of mode instabilities in high-power fiber amplifiers[J]. J Optics, 19, 065202(2017).

[151] [151] Smith J J, Smith A V. Influence of signal bwidth on mode instability thresholds of fiber amplifiers[C]Proc of SPIE. 2015: 93440L.

[152] Tao R, Ma P, Wang X. Study of wavelength dependence of mode instability based on a semi-analytical model[J]. IEEE J Quantum Elect, 51, 1600106(2015).

[153] [153] Otto H, Modsching N, Jauregui C, et al. Wavelength dependence of maximal diffractionlimited output power of fiber lasers[C]Proc of SPIE. 2015: 93441Y.

[154] [154] Sanjabi Eznaveh Z, LópezGalmiche G, AntonioLópez E, et al. Bidirectional pump configuration f increasing thermal modal instabilities threshold in high power fiber amplifiers[C]Proc of SPIE. 2015: 93442G.

[155] [155] Naderi S, Dajani I, Grosek J, et al. Theetical analysis of effect of pump signal wavelengths on modal instabilities in Ybdoped fiber amplifiers[C]Proc of SPIE. 2014: 89641W.

[156] Jauregui C, Otto H, Breitkopf S. Optimizing high-power Yb-doped fiber amplifier systems in the presence of transverse mode instabilities[J]. Opt Express, 24, 7879(2016).

[157] Tao R, Ma P, Wang X. Theoretical study of pump power distribution on modal instabilities in high power fiber amplifiers[J]. Laser Phys Lett, 14, 025002(2017).

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

[159] Tao R, Su R, Ma P. Suppressing mode instabilities by optimizing the fiber coiling methods[J]. Laser Phys Lett, 14, 25101(2017).

[160] Otto H, Modsching N, Jauregui C. Impact of photodarkening on the mode instability threshold[J]. Opt Express, 23, 15265(2015).

[161] Chen Y S, Xu H Z, Xing Y B. Impact of gamma-ray radiation-induced photodarkening on mode instability degradation of an ytterbium-doped fiber amplifier[J]. Opt Express, 26, 20430(2018).

[162] Hejaz K, Norouzey A, Poozesh R. Controlling mode instability in a 500 W ytterbium-doped fiber laser[J]. Laser Phys, 24, 25102(2014).

[163] Pulford B, Ehrenreich T, Holten R. 400-W near diffraction-limited single-frequency all-solid photonic bandgap fiber amplifier[J]. Opt Lett, 40, 2297(2015).

[164] Hochheim S, Steinke M, Wessels P. Single-frequency chirally coupled-core all-fiber amplifier with 100 W in a linearly polarized TEM₀₀ mode[J]. Opt Lett, 45, 939(2020).

[165] Filippov V, Kerttula J, Chamorovskii Y. Highly efficient 750 W tapered double-clad ytterbium fiber laser[J]. Opt Express, 18, 12499-12512(2010).

[166] Trikshev A I, Kurkov A S, Tsvetkov V B. A 160 W single-frequency laser based on an active tapered double-clad fiber amplifier[J]. Laser Phys Lett, 10, 065101(2013).

[167] Shi C, Zhang H, Wang X. kW-class high power fiber laser enabled by active long tapered fiber[J]. High Power Laser Science and Engineering, 6, e16(2018).

[168] Spirin V V, López-Mercado C A, Kinet D. A single-longitudinal-mode Brillouin fiber laser passively stabilized at the pump resonance frequency with a dynamic population inversion grating[J]. Laser Phys Lett, 10, 015102(2013).

[169] Chen M, Meng Z, Wang J. Strong linewidth reduction by compact Brillouin/erbium fiber laser[J]. IEEE Photonics J, 6, 1-8(2014).

[170] Chen M, Meng Z, Zhang Y. Ultranarrow-linewidth Brillouin/erbium fiber laser based on 45-cm erbium-doped fiber[J]. IEEE Photonics J, 7, 1-6(2015).

[171] Huang S, Zhu T, Yin G. Tens of hertz narrow-linewidth laser based on stimulated Brillouin and Rayleigh scattering[J]. Opt Lett, 42, 5286-5289(2017).

[172] Zhu T, Bao X, Chen L. A single longitudinal-mode tunable fiber ring laser based on stimulated Rayleigh scattering in a nonuniform optical fiber[J]. J Lightwave Technol, 29, 1802-1807(2011).

[173] Yin G, Saxena B, Bao X. Tunable Er-doped fiber ring laser with single longitudinal mode operation based on Rayleigh backscattering in single mode fiber[J]. Opt Express, 19, 25981(2011).

[174] Zhu T, Chen F Y, Huang S H. An ultra-narrow linewidth fiber laser based on Rayleigh backscattering in a tapered optical fiber[J]. Laser Phys Lett, 10, 055110(2013).

[175] Shupei Mo Z L X H, Zhang W, Li C. 820 Hz linewidth short-linear-cavity single- frequency fiber laser at 1.5 mm[J]. Laser Phys Lett, 11, 035101(2014).

[176] Mo S, Huang X, Xu S. 600-Hz linewidth short-linear-cavity fiber laser[J]. Opt Lett, 39, 5818(2014).

[177] Pan Z, Ye Q, Cai H. Fiber ring with long delay used as a cavity mirror for narrowing fiber laser[J]. IEEE Photonic Tech L, 26, 1621-1624(2014).

[178] Mo S, Huang X, Xu S. Compact slow-light single-frequency fiber laser at 1550 nm[J]. Appl Phys Express, 8, 82703(2015).

[179] Huang X, Zhao Q, Lin W. Linewidth suppression mechanism of self-injection locked single-frequency fiber laser[J]. Opt Express, 24, 18907(2016).

[180] [180] Zhu T, Huang S, Shi L, et al. Ultranarrow linewidth fiber laser with selfinjection feedback based on Rayleigh backscattering[C]Conference on Lasers ElectroOptics. 2014: SW1N5.

[181] Kovalev V I, Harrison R. Waveguide-induced inhomogeneous spectral broadening of stimulated Brillouin scattering in optical fiber[J]. Opt Lett, 27, 2022(2002).

[182] Ke W, Wang X, Tang X. Stimulated Brillouin scattering model in multi-mode fiber lasers[J]. IEEE J Sel Top Quant, 20, 305-314(2014).

[183] Lu H, Zhou P, Wang X. Theoretical and numerical study of the threshold of stimulated Brillouin scattering in multimode fibers[J]. J Lightwave Technol, 33, 4464-4470(2015).

[184] Zeringue C, Dajani I, Naderi S. A theoretical study of transient stimulated Brillouin scattering in optical fibers seeded with phase-modulated light[J]. Opt Express, 20, 21196-21213(2012).

[185] Meier T, Willke B, Danzmann K. Continuous-wave single-frequency 532 nm laser source emitting 130 W into the fundamental transversal mode[J]. Opt Lett, 35, 3742(2010).

[186] Cui S, Zhang L, Jiang H. High efficiency frequency doubling with a passive enhancement cavity[J]. Laser Phys Lett, 16, 35105(2019).

[187] Taylor L R, Feng Y, Calia D B. 50W CW visible laser source at 589nm obtained via frequency doubling of three coherently combined narrow-band Raman fibre amplifiers[J]. Opt Express, 18, 8540(2010).

[188] Zhang L, Jiang H, Cui S. Versatile Raman fiber laser for sodium laser guide star[J]. Laser Photonics Rev, 8, 889-895(2014).

[189] Dong J, Zeng X, Cui S. More than 20 W fiber-based continuous-wave single frequency laser at 780 nm[J]. Opt Express, 27, 35362(2019).

[190] Kwon M, Yang P, Huft P. Generation of 14.0 W of single-frequency light at 770 nm by intracavity frequency doubling[J]. Opt Lett, 45, 339-342(2020).

[191] Shukla M K, Das R. High-power single-frequency source in the mid-infrared using a singly resonant optical parametric oscillator pumped by Yb-fiber laser[J]. IEEE J Sel Top Quant, 24, 1-6(2018).

[192] Gouhier B, Guiraud G, Rota-Rodrigo S. 25 W single-frequency, low noise fiber MOPA at 1120 nm[J]. Opt Lett, 43, 308-311(2018).

[193] Ma P, Miao Y, Liu W. Kilowatt-level ytterbium-Raman fiber amplifier with a narrow-linewidth and near-diffraction-limited beam quality[J]. Opt Lett, 45, 1974(2020).

[194] Goodno G D, Mcnaught S J, Rothenberg J E. Active phase and polarization locking of a 1.4 kW fiber amplifier[J]. Opt Lett, 35, 1542-1544(2010).

[195] Yu C X, Augst S J, Redmond S M. Coherent combining of a 4 kW, eight-element fiber amplifier array[J]. Opt Lett, 36, 2686-2688(2011).

[196] [196] Shekel E, Vidne Y, Urbach B. 16 kW single mode CW laser with dynamic beam f material processing[C]Proc of SPIE. 2020: 1126021.

[197] [197] Fsaifes I, Daniault L, Bellanger S, et al. Coherent beam combining of 60 femtosecond fiber amplfiers[C]Proc of SPIE. 2020: 112600L.

[198] Flores A, Dajani I, Holten R. Multi-kilowatt diffractive coherent combining of pseudorandom-modulated fiber amplifiers[J]. Opt Eng, 55, 96101(2016).

[199] Muller M, Aleshire C, Klenke A. 10.4 kW coherently combined ultrafast fiber laser[J]. Opt Lett, 45, 3083-3086(2020).

[200] [200] Honea E, Afzal R S, SavageLeuchs M, et al. Advances in fiber laser spectral beam combining f power scaling[C]Proc of SPIE. 2016: 97300Y.

[201] Zheng Y, Yang Y, Wang J. 10.8 kW spectral beam combination of eight all-fiber superfluorescent sources and their dispersion compensation[J]. Opt Express, 24, 12063(2016).

[202] Chen F, Ma J, Wei C. 10 kW-level spectral beam combination of two high power broad-linewidth fiber lasers by means of edge filters[J]. Opt Express, 25, 32783(2017).

[203] Zheng Y, Zhu Z, Liu X. High-power, high-beam-quality spectral beam combination of six narrow-linewidth fiber amplifiers with two transmission diffraction gratings[J]. Appl Opt, 58, 8339(2019).

[205] Su R, Zhou P, Wang X. Active coherent beam combining of a five-element, 800 W nanosecond fiber amplifier array[J]. Opt Lett, 37, 3978-3980(2012).

[207] Piracha M U, Nguyen D, Mandridis D. Range resolved lidar for long distance ranging with sub-millimeter resolution[J]. Opt Express, 18, 7184(2010).

[208] Vercesi V, Onori D, Laghezza F. Frequency-agile dual-frequency lidar for integrated coherent radar-lidar architectures[J]. Opt Lett, 40, 1358(2015).

[209] Yang F, Ye Q, Pan Z. 100-mW linear polarization single-frequency all-fiber seed laser for coherent Doppler lidar application[J]. Opt Commun, 285, 149-152(2012).