Abstract: Dy³⁺-doped fluoride fiber lasers have important applications in environment monitoring, real-time sensing, and polymer processing. At present, achieving a high-efficiency and high-power Dy³⁺-doped fluoride fiber laser in the mid-infrared (mid-IR) region over 3 μm is a scientific and technological frontier. Typically, Dy³⁺-doped fluoride fiber lasers use a unidirectional pumping method, which suffers from the drawback of high thermal loading density on the fiber tips, thus limiting power scalability. In this study, a bi-directional in-band pumping scheme, to address the limitations of output power scaling and to enhance the efficiency of the Dy³⁺-doped fluoride fiber laser at 3.2 μm, is investigated numerically based on rate equations and propagation equations. Detailed simulation results reveal that the optical‍‒‍optical efficiency of the bi-directional in-band pumped Dy³⁺-doped fluoride fiber laser can reach 75.1%, approaching the Stokes limit of 87.3%. The potential for further improvement of the efficiency of the Dy³⁺-doped fluoride fiber laser is also discussed. The bi-directional pumping scheme offers the intrinsic advantage of mitigating the thermal load on the fiber tips, unlike unidirectional pumping, in addition to its high efficiency. As a result, it is expected to significantly scale the power output of Dy³⁺-doped fluoride fiber lasers in the mid-IR regime.

双向同带泵浦的3.2 µm掺镝氟化物光纤激光器数值研究

[1]Amin Z, Majewski MR, Woodward RI, et al., 2020. Novel near-infrared pump wavelengths for dysprosium fiber lasers. J Lightw Technol, 38(20):5801-5808.

[2]Aydin YO, Fortin V, Vallée R, et al., 2018. Towards power scaling of 2.8 μm fiber lasers. Opt Lett, 43(18):4542-4545.

[3]Bharathan G, Jiang XT, Zhang H, et al., 2019. Mode-locked mid-IR fibre laser based on 2D nanomaterials. Proc SPIE 11200, AOS Australian Conf on Optical Fibre Technology (ACOFT) and Australian Conf on Optics, Lasers, and Spectroscopy (ACOLS), p.124-125.

[4]Crawford S, Hudson DD, Jackson SD, 2015. High-power broadly tunable 3-μm fiber laser for the measurement of optical fiber loss. IEEE Photon J, 7(3):1502309.

[5]Falconi MC, Laneve D, Bozzetti M, et al., 2018. Design of an efficient pulsed Dy³⁺: ZBLAN fiber laser operating in gain switching regime. J Lightw Technol, 36(23):5327-5333.

[6]Faucher D, Bernier M, Androz G, et al., 2011. 20 W passively cooled single-mode all-fiber laser at 2.8 μm. Opt Lett, 36(7):1104-1106.

[7]Fortin V, Jobin F, Larose M, et al., 2019. 10-W-level monolithic dysprosium-doped fiber laser at 3.24 μm. Opt Lett, 44(3):491-494.

[8]Hu Y, Wang MK, Hu LP, et al., 2022. Recent advances in two-dimensional graphdiyne for nanophotonic applications. Chem Eng J, 450:138228.

[9]Huang J, Pang M, Jiang X, et al., 2020. Sub-two-cycle octave-spanning mid-infrared fiber laser. Optica, 7(6):574-579.

[10]Huang WC, Ma CY, Li C, et al., 2020. Highly stable MXene (V₂CT_x)-based harmonic pulse generation. Nanophotonics, 9(8):2577-2585.

[11]Ilev IK, Waynant RW, 2006. Mid-infrared biomedical applications. In: Krier A (Ed.), Mid-Infrared Semiconductor Optoelectronics. Springer, London, p.615-634.

[12]Jackson SD, 2003. Continuous wave 2.9 μm dysprosium-doped fluoride fiber laser. Appl Phys Lett, 83(7):1316-1318.

[13]Jackson SD, 2012. Towards high-power mid-infrared emission from a fibre laser. Nat Photon, 6(7):423-431.

[14]Jobin F, Paradis P, Fortin V, et al., 2020. 1.4 W in-band pumped Dy³⁺-doped gain-switched fiber laser at 3.24 μm. Opt Lett, 45(18):5028-5031.

[15]Jobin F, Paradis P, Aydin YO, et al., 2022. Recent developments in lanthanide-doped mid-infrared fluoride fiber lasers [Invited]. Opt Express, 30(6):8615-8640.

[16]Li JF, Jackson SD, 2012. Numerical modeling and optimization of diode pumped heavily-erbium-doped fluoride fiber lasers. IEEE J Quantum Elect, 48(4):454-464.

[17]Li JF, Hudson DD, Liu Y, et al., 2012. Efficient 2.87 μm fiber laser passively switched using a semiconductor saturable absorber mirror. Opt Lett, 37(18):3747-3749.

[18]Luo HY, Wang YZ, Chen JS, et al., 2022. Red-diode-clad-pumped Er³⁺/Dy³⁺ codoped ZrF₄ fiber: a promising mid-infrared laser platform. Opt Lett, 47(20):5313-5316.

[19]Luo HY, Shi JC, Chen JS, et al., 2023. Towards high-power and -efficiency ~2.8 μm lasing: lightly-erbium-doped ZrF fiber laser pumped at ~1.7 μm. J Lightw Technol, 42(1):316-325.

[20]Majewski MR, Jackson SD, 2016. Highly efficient mid-infrared dysprosium fiber laser. Opt Lett, 41(10):2173-2176.

[21]Majewski MR, Woodward RI, Jackson SD, 2018. Dysprosium-doped ZBLAN fiber laser tunable from 2.8 μm to 3.4 μm, pumped at 1.7 μm. Opt Lett, 43(5):971-974.

[22]Majewski MR, Amin Z, Berthelot T, et al., 2019. Directly diode-pumped mid-infrared dysprosium fiber laser. Opt Lett, 44(22):5549-5552.

[23]Majewski MR, Woodward RI, Jackson SD, 2020. Dysprosium mid-infrared lasers: current status and future prospects. Laser Photon Rev, 14(3):1900195.

[24]Majewski MR, Bharathan G, Fuerbach A, et al., 2021. Long wavelength operation of a dysprosium fiber laser for polymer processing. Opt Lett, 46(3):600-603.

[25]Pajewsk L, Sójka L, Lamrin S, et al., 2023. Experimental investigation of actively Q-switched Dy³⁺ doped fluoride single mode fiber laser operating near 3 μm. J Lightw Technol, 42(2):809-813.

[26]Pan H, Chu HW, Li Y, et al., 2023. Bismuthene quantum dots integrated D-shaped fiber as saturable absorber for multi-type soliton fiber lasers. J Materiom, 9(1):183-190.

[27]Qin ZP, Xie GQ, Gu HA, et al., 2019. Mode-locked2.8-‍μm fluoride fiber laser: from soliton to breathing pulse. Adv Photon, 1(6):065001.

[28]Qin ZP, Chai XL, Xie GQ, et al., 2022. Semiconductor saturable absorber mirror in the 3‍‒‍5 μm mid-infrared region. Opt Lett, 47(4):890-893.

[29]Quimby RS, Shaw LB, Sanghera JS, et al., 2008. Modeling of cascade lasing in Dy: chalcogenide glass fiber laser with efficient output at 4.5 μm. IEEE Photon Technol Lett, 20(2):123-125.

[30]Shen YL, Wang YS, Chen HW, et al., 2017. Wavelength-tunable passively mode-locked mid-infrared Er³⁺-doped ZBLAN fiber laser. Sci Rep, 7(1):14913.

[31]Sijan A, 2009. Development of military lasers for optical countermeasures in the mid-IR. Technologies for Optical Countermeasures VI, p.32-45.

[32]Sójka L, Pajewski L, Popenda M, et al., 2018. Experimental investigation of mid-infrared laser action from Dy³⁺ doped fluorozirconate fiber. IEEE Photon Technol Lett, 30(12):1083-1086.

[33]Sujecki S, 2014. An efficient algorithm for steady state analysis of fibre lasers operating under cascade pumping scheme. Int J Electron Telec, 60(2):143-149.

[34]Tang PH, Wang YC, Vicentini E, et al., 2022. Single-frequency Dy: ZBLAN fiber laser tunable in the wavelength range from 2.925 to 3.250 μm. J Lightw Technol, 40(8):2489-2493.

[35]Tsang YH, El-Taher AE, 2011. Efficient lasing at near 3 µm by a Dy-doped ZBLAN fiber laser pumped at ~1.1 µm by an Yb fiber laser. Laser Phys Lett, 8(11):818-822.

[36]Tsang YH, El-Taher AE, King TA, et al., 2006. Efficient 2.96 micron dysprosium-doped ZBLAN fibre laser pumped at 1.3 micron. Solid State Lasers and Amplifiers II, p.156-165.

[37]Wang C, Xu JW, Wang YZ, et al., 2021. MXene (Ti₂NT_x): synthesis, characteristics and application as a thermo-optical switcher for all-optical wavelength tuning laser. Sci China Mater, 64(1):259-265.

[38]Wang YC, Jobin F, Duval S, et al., 2019. Ultrafast Dy³⁺: fluoride fiber laser beyond 3 μm. Opt Lett, 44(2):395-398.

[39]Wang YZ, Luo HY, Gong HT, et al., 2022. Watt-level and tunable operations of 3 μm-class dysprosium ZrF₄ fiber laser pumped at 1.69 μm. IEEE Photon Technol Lett, 34(14):737-740.

[40]Wang ZH, Zhang B, Liu J, et al., 2020. Recent developments in mid-infrared fiber lasers: status and challenges. Opt Laser Technol, 132:106497.

[41]Woodward RI, Gorjan M, 2022. Modeling mid-infrared fiber laser systems. In: Jackson S, Bernier M, Vallée R (Eds.), Mid-Infrared Fiber Photonics. Woodhead Publishing, London, England, p.743-801.

[42]Woodward RI, Majewski MR, Bharathan G, et al., 2018. Watt-level dysprosium fiber laser at 3.15 μm with 73% slope efficiency. Opt Lett, 43(7):1471-1474.

[43]Wu Q, Wang YY, Zhao G, et al., 2023. 2 µm passively Q-switched Tm: YAG pulse laser with a graphdiyne saturable absorber. Infrared Phys Technol, 134:104914.

[44]Xiao Y, Xiao XS, He CJ, et al., 2024. Gain-switched 3 μm dysprosium-doped fluoride fiber laser pumped at 1.7 μm. Opt Laser Technol, 169:110162.

[45]Ycas G, Giorgetta FR, Baumann E, et al., 2018. High-coherence mid-infrared dual-comb spectroscopy spanning 2.6 to 5.2 μm. Nat Photon, 12(4):202-208.

[46]Zhang L, Zhang JX, Sheng Q, et al., 2022. High-efficiency thulium-doped fiber laser at 1.7 μm. Opt Laser Technol, 152:108180.