[1] Keller U. Recent developments in compact ultrafast lasers[J]. Nature, 424, 831-838(2003).

[2] Han Y G, Tran T V A, Kim S H et al. Multiwavelength Raman-fiber-laser-based long-distance remote sensor for simultaneous measurement of strain and temperature[J]. Optics Letters, 30, 1282-1284(2005).

[3] Hu M L, Cai Y. Research progress on mid-infrared ultrafast fiber laser[J]. Chinese Journal of Lasers, 47, 0500009(2020).

[4] Zhao Z X. Research on WDM-PON System and Its Application Based on Multiple-Wavelength Lasers[D](2015).

[5] Lyu X G. Four-wave Mixing Multiwavelength Fiber Laser with Highly Erbium Fiber[D](2019).

[6] Wang J. Research on Technologies of Two-wavelength Single-longitudinal-mode Fiber Laser with Narrow line-width[D](2019).

[7] Wang S K, Ning Q Y, Luo A P et al. Dissipative soliton resonance in a passively mode-locked figure-eight fiber laser[J]. Optics Express, 21, 2402-2407(2013).

[8] Huang H C, Yang T, Yuan X Z et al. An easily switchable dual-wavelength passively mode-locked erbium fiber laser[J]. Chinese Physics Letters, 31, 014204(2014).

[9] Kong Y C, Yang H R, Li W L et al. Switchable dual-wavelength all-fiber laser mode-locked by carbon nanotubes[J]. Laser Physics, 25, 015101(2015).

[10] Wang Y Z, Li J F, Zhai B et al. Tunable and switchable dual-wavelength mode-locked Tm3+-doped fiber laser based on a fiber taper[J]. Optics Express, 24, 15299-15306(2016).

[11] Feng Q, Chen Y, Zhao C J et al. Experimental study on the multisoliton pattern formation in an erbium-doped fiber laser passively mode-locked by graphene saturable absorber[J]. Optical Engineering, 52, 044201(2013).

[12] Wushouer X, Yu H J, Yan P et al. Investigation on mode matching including thermal effects in LD end-pumped passively mode-locked Nd:YVO4 laser[J]. Chinese Optics Letters, 8, 1004-1007(2010).

[13] Li F Q, Zong N, Wang Z C et al. Passively mode-locked grown-together composite YVO4/Nd:YVO4 crystal laser with a semiconductor saturable absorber mirror under 880-nm direct pumping[J]. Chinese Optics Letters, 9, 041405(2011).

[14] Marshall J, Stewart G, Whitenett G. Design of a tunable L-band multi-wavelength laser system for application to gas spectroscopy[J]. Measurement Science and Technology, 17, 1023-1031(2006).

[15] Jeon H B, Lee H. Photonic true-time delay for phased-array antenna system using dispersion compensating module and a multiwavelength fiber laser[J]. Journal of the Optical Society of Korea, 18, 406-413(2014).

[16] Fu J, Chen D, Sun B et al. A novel-configuration multi-wavelength Brillouin erbium fiber laser and its application in switchable high-frequency microwave generation[J]. Laser Physics, 20, 1907-1912(2010).

[17] Chen H L, Jiang X T, Xu S X et al. Recent progress in multi-wavelength fiber lasers: Principles, status, and challenges[J]. Chinese Optics Letters, 18, 041405(2020).

[18] Liu X M, Han D D, Sun Z P et al. Versatile multi-wavelength ultrafast fiber laser mode-locked by carbon nanotubes[J]. Scientific Reports, 3, 2718(2013).

[19] Luo Z C, Luo A P, Xu W C. Tunable and switchable multiwavelength passively mode-locked fiber laser based on SESAM and inline birefringence comb filter[J]. IEEE Photonics Journal, 3, 64-70(2011).

[20] Ding X D, He W, Yan G et al. Tunable fiber laser based on Mach-Zehnder filter[J]. Laser & Infrared, 46, 1068-1072(2016).

[21] Yamashita S, Hotate K. Multiwavelength erbium-doped fibre laser using intracavity etalon and cooled by liquid nitrogen[J]. Electronics Letters, 32, 1298-1299(1996).

[22] Agrawal G P. Nonlinear fiber optics[M]. Nonlinear Science at the Dawn of the 21st Century, 195-211(2000).

[23] Schlager J B, Kawanishi S, Saruwatari M. Dual wavelength pulse generation using mode-locked erbium-doped fibre ring laser[J]. Electronics Letters, 27, 2072-2073(1991).

[24] Li S P, Chan K T. Electrical wavelength tunable and multiwavelength actively mode-locked fiber ring laser[J]. Applied Physics Letters, 72, 1954-1956(1998).

[25] Zhao Y, Shu C. A fiber laser for effective generation of tunable single- and dual-wavelength mode-locked optical pulses[J]. Applied Physics Letters, 72, 1556-1558(1998).

[26] Bakhshi B, Andrekson P A. Dual-wavelength 10-GHz actively mode-locked erbium fiber laser[J]. IEEE Photonics Technology Letters, 11, 1387-1389(1999).

[27] Deparis O, Kiyan R, Salik E et al. Round-trip time and dispersion optimization in a dual-wavelength actively mode-locked Er-doped fiber laser including nonchirped fiber Bragg gratings[J]. IEEE Photonics Technology Letters, 11, 1238-1240(1999).

[28] Town G E, Chen L, Smith P W E. Dual wavelength modelocked fiber laser[J]. IEEE Photonics Technology Letters, 12, 1459-1461(2000).

[29] Pudo D, Chen L R. Actively modelocked, quadruple-wavelength fibre laser with pump-controlled wavelength switching[J]. Electronics Letters, 39, 272-274(2003).

[30] Yao J, Yao J P, Deng Z C. Multiwavelength actively mode-locked fiber ring laser with suppressed homogeneous line broadening and reduced supermode noise[J]. Optics Express, 12, 4529-4534(2004).

[31] Noske D U, Guy M J, Rottwitt K et al. Dual-wavelength operation of a passively mode-locked "figure-of-eight" ytterbium-erbium fibre soliton laser[J]. Optics Communications, 108, 297-301(1994).

[32] Yun L, Liu X M, Mao D. Observation of dual-wavelength dissipative solitons in a figure-eight erbium-doped fiber laser[J]. Optics Express, 20, 20992-20997(2012).

[33] Ning Q Y, Wang S K, Luo A P et al. Bright-dark pulse pair in a figure-eight dispersion-managed passively mode-locked fiber laser[J]. IEEE Photonics Journal, 4, 1647-1652(2012).

[34] Jin X X, Wang X, Wang X L et al. Tunable multiwavelength mode-locked Tm/Ho-doped fiber laser based on a nonlinear amplified loop mirror[J]. Applied Optics, 54, 8260-8264(2015).

[35] Shao Z H, Qiao X G, Rong Q Z et al. Generation of dual-wavelength square pulse in a figure-eight erbium-doped fiber laser with ultra-large net-anomalous dispersion[J]. Applied Optics, 54, 6711-6716(2015).

[36] Posada-Ramírez B, Durán-Sánchez M, Álvarez-Tamayo R I et al. Study of a Hi-Bi FOLM for tunable and dual-wavelength operation of a thulium-doped fiber laser[J]. Optics Express, 25, 2560-2568(2017).

[37] Gong Y D, Tian X L, Tang M et al. Generation of dual wavelength ultrashort pulse outputs from a passive mode locked fiber ring laser[J]. Optics Communications, 265, 628-631(2006).

[38] Zhang Z X, Zhan L, Xu K et al. Multiwavelength fiber laser with fine adjustment, based on nonlinear polarization rotation and birefringence fiber filter[J]. Optics Letters, 33, 324-326(2008).

[39] Chen W C, Luo Z C, Xu W C. The interaction of dual wavelength solitons in fiber laser[J]. Laser Physics Letters, 6, 816-820(2009).

[40] Luo Z C, Luo A P, Xu W C et al. Modulation instability induced by cross-phase modulation in a dual-wavelength dispersion-managed soliton fiber ring laser[J]. Applied Physics B, 100, 811-820(2010).

[41] Yun L, Han D D. Evolution of dual-wavelength fiber laser from continuous wave to soliton pulses[J]. Optics Communications, 285, 5406-5409(2012).

[42] Wang X, Zhu Y D, Zhou P et al. Tunable, multiwavelength Tm-doped fiber laser based on polarization rotation and four-wave-mixing effect[J]. Optics Express, 21, 25977-25984(2013).

[43] Zhang Z X, Mou C B, Yan Z J et al. Switchable dual-wavelength Q-switched and mode-locked fiber lasers using a large-angle tilted fiber grating[J]. Optics Express, 23, 1353-1360(2015).

[44] Feehan J S, Ilday F Ö, Brocklesby W S et al. Simulations and experiments showing the origin of multiwavelength mode locking in femtosecond, Yb-fiber lasers[J]. Journal of the Optical Society of America B, 33, 1668-1676(2016).

[45] Zhang H, Tang D Y, Wu X et al. Multi-wavelength dissipative soliton operation of an erbium-doped fiber laser[J]. Optics Express, 17, 12692-12697(2009).

[46] Li J F, Luo H Y, Wang L L et al. Mid-infrared passively switched pulsed dual wavelength Ho3+-doped fluoride fiber laser at 3 μm and 2 μm[J]. Scientific Reports, 5, 10770(2015).

[47] Rigaud P, Kermene V, Simos C et al. Dual-wavelength synchronous ultrashort pulses from a mode-locked Yb-doped multicore fiber laser with spatially dispersed gain[J]. Optics Express, 23, 25308-25315(2015).

[48] Wu Z C, Fu S N, Chen C X et al. Dual-state dissipative solitons from an all-normal-dispersion erbium-doped fiber laser: Continuous wavelength tuning and multi-wavelength emission[J]. Optics Letters, 40, 2684-2687(2015).

[49] Zhang Y F, Yang C S, Feng Z M et al. Dual-wavelength passively q-switched single-frequency fiber laser[J]. Optics Express, 24, 16149-16155(2016).

[50] Wang Y Z, Li J F, Zhang E T et al. Coexistence of noise-like pulse and high repetition rate harmonic mode-locking in a dual-wavelength mode-locked Tm-doped fiber laser[J]. Optics Express, 25, 17192-17200(2017).

[51] Zhao X, Zheng Z, Liu L et al. Fast, long-scan-range pump-probe measurement based on asynchronous sampling using a dual-wavelength mode-locked fiber laser[J]. Optics Express, 20, 25584-25589(2012).

[52] Jiang K, Wu Z C, Fu S N et al. Switchable dual-wavelength mode-locking of thulium-doped fiber laser based on SWNTs[J]. IEEE Photonics Technology Letters, 28, 2019-2022(2016).

[53] Matsas V J, Newson T P, Richardson D J et al. Selfstarting passively mode-locked fibre ring soliton laser exploiting nonlinear polarisation rotation[J]. Electronics Letters, 28, 1391-1393(1992).

[54] Zhao X, Zheng Z, Liu L et al. Switchable, dual-wavelength passively mode-locked ultrafast fiber laser based on a single-wall carbon nanotube modelocker and intracavity loss tuning[J]. Optics Express, 19, 1168-1173(2011).

[55] Fischer M C, Wilson J W, Robles F E et al. Invited review article: pump-probe microscopy[J]. Review of Scientific Instruments, 87, 031101(2016).

[56] Freudiger C W, Yang W L, Holtom G R et al. Stimulated Raman scattering microscopy with a robust fibre laser source[J]. Nature Photonics, 8, 153-159(2014).

[57] Murray R T, Runcorn T H, Kelleher E J R et al. Highly efficient mid-infrared difference-frequency generation using synchronously pulsed fiber lasers[J]. Optics Letters, 41, 2446-2449(2016).

[58] Li Z H, Lou C Y, Gao Y Z et al. A dual-wavelength and dual-repetition-rate actively mode-locked fiber ring laser[J]. Optics Communications, 185, 381-385(2000).

[59] Guo B. Study on Multi-wavelength Mode-locked Fiber Laser Based on Nonlinear Effects of Two-dimensional Materials[D](2015).

[60] Bai Y B, Xiang W H, Zu P et al. Tunable dual-wavelength passively mode-locked Yb-doped fiber laser using SESAM[J]. Chinese Optics Letters, 10, 111405(2012).

[61] Dong L L, Xie F, Ma S et al. Simple tunable dual-wavelength fiber laser and multiple self-mixing interferometry to large step height measurement[J]. Optics Express, 24, 21880-21885(2016).

[62] Wang S, Zhao Z G, Kobayashi Y. Wavelength-spacing controllable, dual-wavelength synchronously mode locked Er:Fiber laser oscillator based on dual-branch nonlinear polarization rotation technique[J]. Optics Express, 24, 28228-28238(2016).

[63] Diaz S. Stable dual-wavelength erbium fiber ring laser with optical feedback for remote sensing[J]. Journal of Lightwave Technology, 34, 4591-4595(2016).

[64] Lau K Y, Abu Bakar M H, Muhammad F D et al. Dual-wavelength, mode-locked erbium-doped fiber laser employing a graphene/polymethyl-methacrylate saturable absorber[J]. Optics Express, 26, 12790-12800(2018).

[65] Zeng J, Li B W, Hao Q et al. Passively synchronized dual-color mode-locked fiber lasers based on nonlinear amplifying loop mirrors[J]. Optics Letters, 44, 5061-5064(2019).

[66] Jiang Y F, Wu J M, Hao Q et al. Experimental study on all-polarization-maintaining passive synchronization for dual-color mode-locked fiber lasers[J]. Acta Optica Sinica, 40, 0936001(2020).

[67] Yoshitomi D, Kobayashi Y, Kakehata M et al. Ultralow-jitter passive timing stabilization of a mode-locked Er-doped fiber laser by injection of an optical pulse train[J]. Optics Letters, 31, 3243-3245(2006).

[68] Huang K, Gu X R, Pan H F et al. Synchronized fiber lasers for efficient coincidence single-photon frequency upconversion[J]. IEEE Journal of Selected Topics in Quantum Electronics, 18, 562-566(2012).

[69] Tsai B W, Wu S Y, Hu C et al. Subfemtosecond hybrid synchronization between ultrafast Yb and Er fiber laser systems by controlling the relative injection timing[J]. Optics Letters, 38, 3456-3459(2013).

[70] Rusu M, Herda R, Okhotnikov O G. Passively synchronized erbium (1550-nm) and ytterbium (1040-nm) mode-locked fiber lasers sharing a cavity[J]. Optics Letters, 29, 2246-2248(2004).

[71] Zhang M, Kelleher E J R, Pozharov A S et al. Passive synchronization of all-fiber lasers through a common saturable absorber[J]. Optics Letters, 36, 3984-3986(2011).

[72] Sotor J, Sobon G, Tarka J et al. Passive synchronization of erbium and thulium doped fiber mode-locked lasers enhanced by common graphene saturable absorber[J]. Optics Express, 22, 5536-5543(2014).

[73] Kim J, Kärtner F X. Attosecond-precision ultrafast photonics[J]. Laser & Photonics Reviews, 4, 432-456(2010).

[74] Luo Z Q, Zhou M, Weng J et al. Graphene-based passively Q-switched dual-wavelength erbium-doped fiber laser[J]. Optics Letters, 35, 3709-3711(2010).

[75] Luo Z Q, Zhou M, Cai Z P et al. Graphene-assisted multiwavelength erbium-doped fiber ring laser[J]. IEEE Photonics Technology Letters, 23, 501-503(2011).

[76] Gong S, Tian J R, Li K X et al. Advances in new two-dimensional materials and its application in solid-state lasers[J]. Chinese Optics, 11, 18-30(2018).

[77] Guo B. Recent advances in multi-wavelength ultrafast lasers based on nonlinear effects of 2D materials[J]. Infrared and Laser Engineering, 48, 0103002(2019).

[78] Lu S B, Zhao C J, Zou Y H et al. Third order nonlinear optical property of Bi2Se3[J]. Optics Express, 21, 2072-2082(2013).

[79] Wang G Z, Zhang S F, Zhang X Y et al. Tunable nonlinear refractive index of two-dimensional MoS2, WS2, and MoSe2 nanosheet dispersions[J]. Photonics Research, 3, A51-A55(2015).

[80] Sun Z P, Hasan T, Torrisi F et al. Graphene mode-locked ultrafast laser[J]. ACS Nano, 4, 803-810(2010).

[81] Song Y W, Jang S Y, Han W S et al. Graphene mode-lockers for fiber lasers functioned with evanescent field interaction[J]. Applied Physics Letters, 96, 051122(2010).

[82] Popa D, Sun Z, Torrisi F et al. Sub 200 fs pulse generation from a graphene mode-locked fiber laser[J]. Applied Physics Letters, 97, 203106(2010).

[83] Martinez A, Fuse K, Xu B et al. Optical deposition of graphene and carbon nanotubes in a fiber ferrule for passive mode-locked lasing[J]. Optics Express, 18, 23054-23061(2010).

[84] Sobon G, Sotor J, Jagiello J et al. Graphene oxide vs. reduced graphene oxide as saturable absorbers for Er-doped passively mode-locked fiber laser[J]. Optics Express, 20, 19463-19473(2012).

[85] Zhang M, Kelleher E J R, Torrisi F et al. Tm-doped fiber laser mode-locked by graphene-polymer composite[J]. Optics Express, 20, 25077-25084(2012).

[86] Luo Z Q, Wang J Z, Zhou M et al. Multiwavelength mode-locked erbium-doped fiber laser based on the interaction of graphene and fiber-taper evanescent field[J]. Laser Physics Letters, 9, 229-233(2012).

[87] Huang S S, Wang Y G, Yan P G et al. Tunable and switchable multi-wavelength dissipative soliton generation in a graphene oxide mode-locked Yb-doped fiber laser[J]. Optics Express, 22, 11417-11426(2014).

[88] Fu L, Kane C L, Mele E J. Topological insulators in three dimensions[J]. Physical Review Letters, 98, 106803(2007).

[89] Zhou J J, Luo A P, Luo Z C et al. Dual-wavelength single-longitudinal-mode fiber laser with switchable wavelength spacing based on a graphene saturable absorber[J]. Photonics Research, 3, A21-A24(2015).

[90] Wang Q H, Kalantar-Zadeh K, Kis A et al. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides[J]. Nature Nanotechnology, 7, 699-712(2012).

[91] Luo Z Q, Zhou M, Wu D D et al. Graphene-induced nonlinear four-wave-mixing and its application to multiwavelength Q-switched rare-earth-doped fiber lasers[J]. Journal of Lightwave Technology, 29, 2732-2739(2011).

[92] Zhao N, Liu M, Liu H et al. Dual-wavelength rectangular pulse Yb-doped fiber laser using a microfiber-based graphene saturable absorber[J]. Optics Express, 22, 10906-10913(2014).

[93] Yun L. Black phosphorus saturable absorber for dual-wavelength polarization-locked vector soliton generation[J]. Optics Express, 25, 32380-32385(2017).

[94] Wang K P, Wang J, Fan J T et al. Ultrafast saturable absorption of two-dimensional MoS2 nanosheets[J]. ACS Nano, 7, 9260-9267(2013).

[95] Guo B, Yao Y, Yan P G et al. Dual-wavelength soliton mode-locked fiber laser with a WS2-based fiber taper[J]. IEEE Photonics Technology Letters, 28, 323-326(2016).

[96] Kieu K, Wise F W. Soliton thulium-doped fiber laser with carbon nanotube saturable absorber[J]. IEEE Photonics Technology Letters, 21, 128-130(2009).

[97] Schmidt A, Rivier S, Cho W B et al. Sub-100 fs single-walled carbon nanotube saturable absorber mode-locked Yb-laser operation near 1 µm[J]. Optics Express, 17, 20109-20116(2009).

[98] Kelleher E J R, Travers J C, Sun Z et al. Nanosecond-pulse fiber lasers mode-locked with nanotubes[J]. Applied Physics Letters, 95, 111108(2009).

[99] Im J H, Choi S Y, Rotermund F et al. All-fiber Er-doped dissipative soliton laser based on evanescent field interaction with carbon nanotube saturable absorber[J]. Optics Express, 18, 22141-22146(2010).

[100] Guo B, Yao Y, Yang Y F et al. Dual-wavelength rectangular pulse erbium-doped fiber laser based on topological insulator saturable absorber[J]. Photonics Research, 3, 94-99(2015).

[101] Man W S, Tam H Y, Demokan M S et al. Mechanism of intrinsic wavelength tuning and sideband asymmetry in a passively mode-locked soliton fiber ring laser[J]. Journal of the Optical Society of America B, 17, 28-33(2000).

[102] Zhu Y J, Xiang F L, Jin L et al. All-fiber dual-wavelength mode-locked laser using a bend-induced-birefringence Lyot-filter as gain-tilt equalizer[J]. IEEE Photonics Journal, 11, 1504807(2019).

[103] Mao D, Lu H. Formation and evolution of passively mode-locked fiber soliton lasers operating in a dual-wavelength regime[J]. Journal of the Optical Society of America B, 29, 2819-2826(2012).

[104] Zhao Q, Pei L, Zheng J J et al. Switchable multi-wavelength erbium-doped fiber laser with adjustable wavelength interval[J]. Journal of Lightwave Technology, 37, 3784-3790(2019).

[105] Luo X, Tuan T H, Saini T S et al. Tunable and switchable all-fiber dual-wavelength mode locked laser based on Lyot filtering effect[J]. Optics Express, 27, 14635-14647(2019).

[106] Zhu Y J, Cui Z K, Sun X N et al. Fiber-based dynamically tunable Lyot filter for dual-wavelength and tunable single-wavelength mode-locking of fiber lasers[J]. Optics Express, 28, 27250-27257(2020).

[107] Li Y. Study on Tunable Multiwavelength Erbium-doped Fiber Laser Based on Birefringent Filter Effect[D](2015).

[108] Liu S X, Zhu X J, Wang C. Switchable and tunable dual-wavelength Yb-doped fiber lasers with asymmetric exposure phase-shifted long-period fiber gratings[C], V2-99-V2-101(2011).

[109] Luo A P, Luo Z C, Xu W C. Switchable dual-wavelength passively mode-locked fiber ring laser using SESAM and cascaded fiber Bragg gratings[J]. Laser Physics, 21, 395-398(2011).

[110] Han D D. Switchable mode-locking fiber laser with fiber Bragg gratings[J]. Optical Engineering, 51, 114202(2012).

[111] Tan X M, Chen H J, Cui H et al. Tunable and switchable dual-waveband ultrafast fiber laser with 100 GHz repetition-rate[J]. Optics Express, 25, 16291-16299(2017).

[112] He W, Zhu L Q, Dong M L et al. Wavelength-switchable and stable-ring-cavity, erbium-doped fiber laser based on Mach-Zehnder interferometer and tunable filter[J]. Laser Physics, 28, 045104(2018).

[113] Zhao X L, Dong M L, Zhang Y M et al. Switchable multi-wavelength and tunable wavelength spacing erbium-doped fiber laser based on a phase-shifted fiber Bragg grating combined with a Mach-Zehnder interferometer[J]. Optics & Laser Technology, 112, 500-507(2019).

[114] Zhao X L, Dong M L, Zhang Y M et al. Switchable dual-wavelength fiber laser based on a phase-shifted fiber Bragg grating combined with Mach-Zehnder interferometer and Sagnac loop[J]. Optical Fiber Technology, 48, 104-109(2019).

[115] Zheng W J, Ruan S C, Zhang M et al. Switchable multi-wavelength erbium-doped photonic crystal fiber laser based on nonlinear polarization rotation[J]. Optics & Laser Technology, 50, 145-149(2013).

[116] Tang D Y, Zhao L M, Zhao B et al. Mechanism of multisoliton formation and soliton energy quantization in passively mode-locked fiber lasers[J]. Physical Review A, 72, 043816(2005).

[117] Sun M Q, Wang X D, Yang S M et al. Switchable dual-wavelength femtosecond mode-locked fiber laser[J]. Laser & Infrared, 51, 46-51(2021).

[118] Yan Z Y, Li X H, Tang Y L et al. Tunable and switchable dual-wavelength Tm-doped mode-locked fiber laser by nonlinear polarization evolution[J]. Optics Express, 23, 4369-4376(2015).

[119] Song C X, Xu W C, Luo Z C et al. Switchable and tunable dual-wavelength ultrashort pulse generation in a passively mode-locked erbium-doped fiber ring laser[J]. Optics Communications, 282, 4408-4412(2009).

[120] Zhu X J, Wang C H, Liu S X et al. Switchable dual-wavelength and passively mode-locked all-normal-dispersion Yb-doped fiber lasers[J]. IEEE Photonics Technology Letters, 23, 956-958(2011).

[121] Dong J L, Xu W C, Luo Z C et al. Tunable and switchable dual-wavelength passively mode-locked fiber ring laser with high-energy pulses at a sub-100 kHz repetition rate[J]. Optics Communications, 284, 5719-5722(2011).

[122] Zhang Z X, Xu Z W, Zhang L. Tunable and switchable dual-wavelength dissipative soliton generation in an all-normal-dispersion Yb-doped fiber laser with birefringence fiber filter[J]. Optics Express, 20, 26736-26742(2012).

[123] Lin H Q, Guo C Y, Ruan S C et al. Tunable and switchable dual-wavelength dissipative soliton operation of a weak-birefringence all-normal-dispersion Yb-doped fiber laser[J]. IEEE Photonics Journal, 5, 1501807(2013).

[124] Xu Z W, Zhang Z X. All-normal-dispersion multi-wavelength dissipative soliton Yb-doped fiber laser[J]. Laser Physics Letters, 10, 085105(2013).

[125] Xin Y X, Shen H B, Zhang S M et al. Tunable multi-wavelength bright-dark and dark-bright pulse pairs fiber lasers[J]. IEEE Photonics Journal, 12, 7103209(2020).

[126] Wu X M, Dong X F, Jiang L et al. Properties and application of tapered fiber[J]. Journal of Suzhou University of Science and Technology (Natural Science), 32, 52-55(2015).

[127] Coviello G, Finazzi V, Villatoro J et al. Thermally stabilized PCF-based sensor for temperature measurements up to 1000 oC[J]. Optics Express, 17, 21551-21559(2009).

[128] Musa B, Mustapha Kamil Y, Abu Bakar M H et al. Effects of taper parameters on free spectral range of non-adiabatic tapered optical fibers for sensing applications[J]. Microwave and Optical Technology Letters, 58, 798-803(2016).

[129] Yadav T K, Mustapa M A, Abu Bakar M H et al. Study of single mode tapered fiber-optic interferometer of different waist diameters and its application as a temperature sensor[J]. Journal of the European Optical Society: Rapid Publications, 9, 14024(2014).

[130] Zulkhairi A S, Azzuhri S R, Shaharuddin R A et al. Switchable multiwavelength ytterbium-doped fiber laser using a non-adiabatic microfiber interferometer[J]. Laser Physics, 27, 055104(2017).

[131] Zhou Y X, Lou S Q, Tang Z J et al. Tunable and switchable C-band and L-band multi-wavelength erbium-doped fiber laser employing a large-core fiber filter[J]. Optics & Laser Technology, 111, 262-270(2019).

[132] Jiao M X, Xing J H, Tong C W et al. Design and experimental study of two-wavelength single-longitudinal-mode erbium-doped fiber ring laser[J]. Chinese Journal of Lasers, 40, 0602013(2013).

[133] Xi M. Design and Experimental Study of Two-wavelength Single-longitudinal-mode Ytterbium-erbium Co-doped Fiber Laser[D](2017).

[134] Wang X. Study on Single Longitudinal Mode and Multi-wavelength Thulium-doped Fiber Laser[D](2019).

[135] Cheng X P, Shum P, Tse C H et al. Single-longitudinal-mode erbium-doped fiber ring laser based on high finesse fiber Bragg grating fabry–PÉrot etalon[J]. IEEE Photonics Technology Letters, 20, 976-978(2008).

[136] Chen X F, Yao J P, Zeng F et al. Single-longitudinal-mode fiber ring laser employing an equivalent phase-shifted fiber Bragg grating[J]. IEEE Photonics Technology Letters, 17, 1390-1392(2005).

[137] He X Y, Fang X, Liao C R et al. A tunable and switchable single-longitudinal-mode dual-wavelength fiber laser with a simple linear cavity[J]. Optics Express, 17, 21773-21781(2009).

[138] Pan S L, Yao J P. A wavelength-switchable single-longitudinal-mode dual-wavelength erbium-doped fiber laser for switchable microwave generation[J]. Optics Express, 17, 5414-5419(2009).

[139] Zhang K, Kang J U. C-band wavelength-swept single-longitudinal-mode erbium-doped fiber ring laser[J]. Optics Express, 16, 14173-14179(2008).

[140] Zhang Y, Chen W, Ren M et al. Stable, tunable single-longitudinal-mode erbium-doped fiber laser with multiple ring cavities[J]. Acta Optica Sinica, 28, 507-511(2008).

[141] Moore P J, Chaboyer Z J, Das G. Tunable dual-wavelength fiber laser[J]. Optical Fiber Technology, 15, 377-379(2009).

[142] Sun J Q, Chen J L, Huang Y X et al. Wavelength switchable single-longitudinal-mode fiber laser with two π phase-shifted chirped fiber Bragg grating as a narrow linewidth filter[J]. Optical Engineering, 49, 091007(2010).

[143] Md Ali M I, Ibrahim S A, Abu Bakar M H et al. Tapered-EDF-based Mach-Zehnder interferometer for dual-wavelength fiber laser[J]. IEEE Photonics Journal, 6, 5501209(2014).

[144] Hou Y B, Zhang Q, Qi S X et al. Dual-frequency Yb3+-doped DBR fiber laser with 32 GHz frequency difference[J]. Infrared and Laser Engineering, 47, 1005005(2018).

[145] Fu P, Feng X Q, Lu B L et al. Switchable dual-wavelength SLM narrow linewidth fiber laser based on nonlinear amplifying loop mirror[J]. Optics & Laser Technology, 98, 56-60(2018).