Rare-earth-doped optical fibers are one of the most promising solid-state lasers. In these fiber lasers, a cladding-pumping scheme using double-clad fibers is utilized to increase the overall conversion efficiency of pumping light. To maintain acceptable beam quality, the low-numerical aperture large-mode-area fibers is effective for the double-clad fibers because the effects of stimulated Raman scattering can be reduced via the corresponding reduction in the power density in the large fiber core. For the large-mode-area double-clad fibers, fiber fuse propagation was investigated theoretically by the explicit finite-difference method using the thermochemical SiOx production model. In the calculation, we assumed the fiber to be in an atmosphere and that part (40 μm in length) of the core was heated to a temperature of 2,923 K. The threshold power for the double-clad fiber with the core radius of 10 μm was 1.6 W at 1.080 μm and it was close to the experimental value. The power dependence of the velocity of fiber fuse propagation was calculated for the double-clad fibers with the core radius of 10 and 15 μm. The calculated velocities were in fair agreement with the experimental values observed in the input power range from 1 kW to 3.5 kW at 1.080 μm.
| Published in | Journal of Electrical and Electronic Engineering (Volume 10, Issue 1) |
| DOI | 10.11648/j.jeee.20221001.14 |
| Page(s) | 31-38 |
| Creative Commons |
This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited. |
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Copyright © The Author(s), 2024. Published by Science Publishing Group |
Fiber Laser, Fiber Fuse Phenomenon, Double-Clad Fiber, Finite-Difference Technique
| [1] | Richardson D. J., Nilsson J., and Clarkson W. A. (2010). High power fiber lasers: current status and future perspectives. J. Opt. Soc. Am. B, 27 (11), B63-B92. |
| [2] | Tünnermann A., Schreiber T., and Limpert J. (2010). Fiber lasers and amplifiers: an ultrafast performance evolution. Appl. Opt., 49 (25), F71-F78. |
| [3] | Jauregui C., Limpert J., and Tünnermann A. (2013). High-power fibre lasers. Nat. Photonics, 7, 861-867. |
| [4] | Fermann M. E. and Hartl I. (2013). Ultrafast fibre lasers. Nat. Photonics, 7, 868-874. |
| [5] | Zervas M. N. and Codemand C. A. (2014). High power fiber lasers: a review. IEEE J. Selected Topics Quantum Electron., 20 (5), 0904123. |
| [6] | Shi W., Fang Q., Zhu X., Norwood R. A., and Peyghambarian N. (2014). Fiber lasers and their applications. Appl. Opt., 53 (28), 6554-6568. |
| [7] | Hanna D. C., Percival P. M., Perry I. R., Smart R. G., Suni P. J., Townsend J. E., and Tropper A. C. (1988). Continuous-wave oscillation of a monomode ytterbium-doped fibre laser. Electron. Lett., 24 (17), 1111-1113. |
| [8] | Armitage J. R., Wyatt R., Ainslie B. J., and Craig-Ryan S. P. (1989). Highly efficient 980 nm operation of an Yb3+-doped silica fibre laser. Electron. Lett., 25 (5), 298-299. |
| [9] | Hanna D. C., Percival P. M., Perry I. R., Smart R. G., Suni P. J., and Tropper A. C. (1990). An ytterbium-doped monomode fibre laser: broadly tunable operation from 1.010 μm to 1.162 μm and three-level operation at 974 nm. J. Mod. Opt., 37 (4), 1111-1113. |
| [10] | Allain J. Y., Monerie M., and Poignant H. (1992). Ytterbium-doped fluoride fibre laser operating at 1.02 μm. Electron. Lett., 28 (11), 988-989. |
| [11] | Machechnie C. J., Barnes W. L., Hanna D. C., and Townsend J. E. (1993). High power ytterbium (Yb3+)-doped fibre laser operating in the 1.12 μm region. Electron. Lett., 29 (1), 52-53. |
| [12] | Allain J. Y., Bayon J. F., Monerie M., Bernage P., and Niay P. (1993). Ytterbium-doped silica fibre laser with intracore Bragg gratings operating at 1.02 μm. Electron. Lett., 29 (3), 988-989. |
| [13] | Pask H. M., Archambault J. L., Hanna D. C., Reekie L., Russell P. St. J., Townsend J. E., and Tropper A. C. (1994). Operation of cladding-pumped Yb3+-doped silica fibre lasers in 1 μm region. Electron. Lett., 30 (11), 863-865. |
| [14] | Pask H. M., Carman R. J., Hanna D. C., Tropper A. C., Mackechnie C. J., Barber P. R., and Dawes J. M. (1995). Ytterbium-doped silica fiber lasers: versatile sources for the 1-1.2 μm region. IEEE J. Selected Topics Quantum Electron., 1 (1), 2-13. |
| [15] | Snitzer E., Po H., Hakimi F., Tumminelli R., and McCollum B. C. (1988). Double clad, offset core Nd fiber laser. Conf. on Optical Fiber Sensors, PD5-1. |
| [16] | Inniss D., DiGiovanni D. J., Strasser T. A., Hale A., Headley C., Stentz A. J., Pedrazzani R., Tipton D., Kosinski S. G., Brownlow D. L., Quoi K. W., Kranz K. S., Huff R. G., Espindola R., LeGrange J. D., and Jacobovitz-Veselka G. (1997). Ultrahigh-power single-mode fiber lasers from 1.065 to 1.472 μm using Yb-doped cladding-pumped and cascaded Raman lasers. Proc. Conf. on Lasers and Electro-Optics (CLEO), CPD31. |
| [17] | Muendel M., Engstrom B., Kea D., Laliberte B., Minns R., Robinson R., Rockney B., Zhang Y., Colins R., Gavrilovic P., and Rowley A. (1997). 35-Watt CW singlemode ytterbium fiber laser at 1.1 μm. Proc. Conf. on Lasers and Electro-Optics (CLEO), CPD30. |
| [18] | Boggavarapu D., Caffey D., He X., Gupta S., Srinivasan S., Pleak R., and Patel R. (1998). Ultrahigh-power laser diode array pump source for fiber lasers. Optical Fiber Commun. Conf. (OFC'98), TuH7. |
| [19] | Dominic V., MacCormack S., Waarts R., Sanders S., Bicknese S., Dohle R., Wolak E., Yeh P. S., and Zucker E. (1999). 110 W fibre laser. Electron. Lett., 35 (14), 1158-1160. |
| [20] | Platonov N. S., Gapontsev D. V., Gapontsev V. P., and Shumilin V. (2002). 135 W CW fiber laser with perfect single mode output. Proc. Conf. on Lasers and Electro-Optics (CLEO), CPDC3. |
| [21] | Broderick N. G. R., Offerhaus H. L., Richardson D. J., Sammut R. A., Caplen J., and Dong L. (1999). Large mode area fibers for high power applications. Opt. Fiber Technol., 5, 185-196. |
| [22] | Alvarez-Chavez J. A., Offerhaus H. L., Nilsson J., Turner P. W., Clarkson W. A., and Richardson D. J. (2000). High-energy, high-power ytterbium-doped Q-switched fiber laser. Opt. Lett., 25 (1), 37-39. |
| [23] | Jeong Y., Sahu J. K., Williams R. B., Richardson D. J., Furusawa K., and Nilsson J. (2003). Ytterbium-doped large-core fibre laser with 272 W output power. Electron. Lett., 39 (13), 977-978. |
| [24] | Limpert J., Liem A., Zellmer H., and Tünnerman A. (2003). 500 W continuous-wave fibre laser with excellent beam quality. Electron. Lett., 39 (8), 645-647. |
| [25] | Liu C. -H., Ehlers B., Doerfel F., Heinemann S., Carter A., Tankala K., Farroni J., and Galvanauskas A. (2004). 810 W continuous-wave and single-transverse-mode fibre laser using 20 μm core Yb-doped double-clad fibre. Electron. Lett., 40 (23), 1471-1472. |
| [26] | Jeong Y., Sahu J. K., Payne D. N., and Nilsson J. (2004). Ytterbium-doped large-core fibre laser with 1 kW of continuous-wave output power. Electron. Lett., 40 (8), 470-471. |
| [27] | Jeong Y., Sahu J. K., Payne D. N., and Nilsson J. (2004). Ytterbium-doped large-core fiber laser with 1. 36 kW continuous-wave output power. Opt. Express, 12 (25), 6088-6092. |
| [28] | He B., Zhou J., Lou Q., Xue Y., Li Z., Wang W., Dong J., Wei Y., and Chen W. (2010). 1. 75-kilowatt continuous-wave output fiber laser using homemade ytterbium-doped large-core fiber. Microwave Opt. Technol. Lett., 52 (7), 1668-1671. |
| [29] | Jeong Y., Boyland A. J., Sahu J. K., Chung S., Nilsson J., and Payne D. N. (2009). Multi-kilowatt single-mode ytterbium-doped large-core fiber laser. J. Opt. Soc. Korea, 13 (4), 416-422. |
| [30] | Huang L., Wang W., Leng J., Guo S., Xu X., and Cheng X. (2014). Experimental investigation on evolution of the beam quality in a 2-kW high power fiber amplifier. IEEE Photon. Technol. Lett., 26 (1), 33-36. |
| [31] | Khitrov V., Minelly J. D., Tumminelli R., Petit V., and Pooler E. S. (2014). 3 kW single-mode direct diode-pumped fiber laser. Proc. Soc. Photo-Opt. Instrum. Eng., 8961, 89610V-1-89610V-6. |
| [32] | Yu H., Zhang H., Lv H., Wang X., Leng J., Xiao H., Guo S., Zhou P., Xu X., and Chen J. (2015). 3. 15 kW direct diode-pumped near diffraction-limited all-fiber-integrated fiber laser. Appl. Opt., 54 (14), 4556-4560. |
| [33] | Beier F., Hupel C., Nold J., Kuhn S., Hein S., Ihring J., Sattler B., Haarlammert N., Schreiber T., Eberhardt R., and Tünnermann A. (2016). Narrow linewidth, single mode 3 kW average power from a directly diode pumped ytterbium-doped low NA fiber amplifier. Opt. Express, 24 (6), 6011-6020. |
| [34] | Beier F., Hupel C., Kuhn S., Hein S., Nold J., Proske F., Sattler B., Liem A., Jauregui C., Limpert J., Haarlammert N., Schreiber T., Eberhardt R., and Tünnermann A. (2017). Single mode 4. 3 kW output power from a diode-pumped Yb-doped fiber amplifier. Opt. Express, 25 (13), 14892-14899. |
| [35] | Su R., Tao R., Wang X., Zhang H., Ma P., Zhao P., and Xu X. (2017). 3. 7 kW monolithic narrow linewidth single mode fiber laser through simultaneously suppressing nonlinear effects and mode instability. Laser Phys. Lett., 14, 085102. |
| [36] | Wang Y., Gao C., Tang X., Zhan H., Peng K., Ni L., Liu S., Li Y., Guo C., Wang X., Zhang L., Yu J., Jiang L., Lin H., Wang J., Jing F., and Lin A. (2018). 30/900 Yb-doped aluminophosphosilicate fiber presenting 6. 85-kW laser output pumped with commercial 976-nm laser diodes. IEEE J. Lightwave Technol., 36 (16), 3396-3402. |
| [37] | Xiao Q., Li D., Huang Y., Wang X., Wang Z., Tian J., Yan P., and Gong M. (2018). Directly diode and bi-directional pumping 6 kW continuous-wave all-fibre laser. Laser Phys., 28, 125107. |
| [38] | Shima K., Ikoma S., Uchiyama K., Takubo Y., Kashiwagi M., and Tanaka D. (2018). 5-kW single stage all-fiber Yb-doped single-mode fiber laser for material processing. Proc. Soc. Photo-Opt. Instrum. Eng., 10512, 105120C-1-105120C-6. |
| [39] | Lin H., Xu L., Li C., Shu Q., Chu Q., Xie L., Guo C., Zhao P., Li Z., Wang J., Jing F., and Tang X. (2019). 10. 6 kW high-brightness cascade-end-pumped monolithic fiber lasers directly pumped by laser diodes in step-index large mode area double cladding fiber. Results in Phys., 14, 102479. |
| [40] | Ye Y., Yang B., Wang P., Zeng L., Xi X., Shi C., Zhang H., Wang X., Zhou P., and Xu X. (2021). Industrial 6 kW high-stability single-stage all-fiber laser oscillator based on conventional large mode area ytterbium-doped fiber. Laser Phys., 31, 035104. |
| [41] | Wirth C., Schreiber T., Rekas M., Tsybin I., Peschel T., Eberhardt R., and Tünnermann A. (2010). High-power linear-polarized narrow linewidth photonic crystal fiber amplifier. Proc. Soc. Photo-Opt. Instrum. Eng., 7580, 75801H-1-75801H-6. |
| [42] | Eidam T., Hanf S., Seise E., Andersen T. V., Gabler T., Wirth C., Schreiber T., Limpert J., and Tünnermann A. (2010). Femtosecond fiber CPA system emitting 830 W average output power. Opt. Lett., 35 (2), 94-96. |
| [43] | Eidam T., Wirth C., Jauregui C., Stutzki F., Jansen F., Otto H. -J., Schmidt O., Schreiber T., Limpert J., and Tünnermann A. (2011). Experimental observations of the threshold-like onset of mode instabilities in high power fiber amplifiers. Opt. Express, 19 (14), 13218-13224. |
| [44] | Stutzki F., Otto H. -J., Jansen F., Gaida C., Jauregui C., Limpert J., and Tünnermann A. (2011). High-speed modal decomposition of mode instabilities in high-power fiber lasers. Opt. Lett., 36 (23), 4572-4574. |
| [45] | Karow M., Tünnermann H., Neumann J., Kracht D., and Weβels P. (2012). Beam quality degradation of a single-frequency Yb-doped photonic crystal fiber amplifier with low mode instability threshold power. Opt. Lett., 37 (20), 4242-4244. |
| [46] | Laurila M., Johansen M. M., Hansen K. R., Alkeskjold T. T., Broeng J., and Lægsgaard J. (2012). Distributed mode filtering rod fiber amplifier delivering 292 W with improved mode stability. Opt. Express, 20 (5), 5742-5753. |
| [47] | Haarlammert N., de Vries O., Liem A., Kliner A., Peschel T., Schreiber T., Eberhardt R., and Tünnermann A. (2012). Build up and decay of mode instability in a high power fiber amplifier. Opt. Express, 20 (12), 13274-13283. |
| [48] | Otto H. -J., Stutzki F., Jansen F., Eidam T., Jauregui C., Limpert J., and Tünnermann A. (2012). Temporary dynamics of mode instabilities in high-power fiber lasers and amplifiers. Opt. Express, 20 (14), 15710-15722. |
| [49] | Otto H. -J., Jauregui C., Stutzki F., Jansen F., Limpert J., and Tünnermann A. (2013). Controlling mode instabilities by dynamic mode excitation with an acousto-optic deflector. Opt. Express, 21 (14), 17285-17298. |
| [50] | Johansen M. M., Laurila M., Maack M. D., Noordegraaf D., Jakobsen C., Alkeskjold T. T., and Lægsgaard J. (2013). Frequency resolved transverse mode instability in rod fiber amplifiers. Opt. Express, 21 (19), 21847-21856. |
| [51] | Brar K., Savage-Leuchs M., Henrie J., Courtney S., Dilley C., Afzail R., and Honea E. (2014). Threshold power and fiber degradation induced modal instabilities in high power fiber amplifiers based on large mode area fibers. Proc. Soc. Photo-Opt. Instrum. Eng., 8961, 89611R-1-89611R-9. |
| [52] | Robin C., Dajani I., and Pulford B. (2014). Modal instability-suppressing, single-frequency photonic crystal fiber amplifier with 811 W output power. Opt. Lett., 39 (3), 666-669. |
| [53] | Otto H. -J., Klenke A., Jauregui C., Stutzki F., Limpert J., and Tünnermann A. (2014). Scaling the mode instability threshold with multicore fibers. Opt. Lett., 39 (9), 2680-2683. |
| [54] | Kuznetsov M., Vershinin O., Tyrtyshnyy V., and Antipov O. (2014). Low-threshold mode instability in Yb3+-doped few-mode fiber amplifiers. Opt. Express, 22 (24), 29714-29725. |
| [55] | Yang B., Zhang H., Shi C., Wang X., Zhou P., Xu X., Chen J., Liu Z., and Lu Q. (2016). Mitigating transverse mode instability in all-fiber laser oscillator and scaling power up to 2. 5 kW employing bidirectional-pump scheme. Opt. Express, 24 (24), 27828-27835. |
| [56] | Malleville M. -A., Dauliat R., Benoit A., Leconte B., Darwich D., du Jeu R., Jamier R., Schuster K., and Roy P. (2017). Experimental study of the mode instability onset threshold in high-power FA-LPF lasers. Opt. Lett., 42 (24), 5230-5233. |
| [57] | Alekseev D., Tyrtyshnyy V., Kuznetsov M., and Antipov O. (2018). Transverse-mode instability in high-gain few-mode Yb3+-doped fiber amplifiers with a 10 μm core diameter with or without backward reflection. IEEE J. Selected Topics Quantum Electron., 24 (3), 5100608. |
| [58] | Jauregui C., Stihler C., Tünnermann A., and Limpert J. (2018). Pump-modulation-induced beam stabilization in high-power fiber laser systems above the mode instability threshold. Opt. Express, 26 (8), 10691-10704. |
| [59] | Stihler C., Jauregui C., Tünnermann A., and Limpert J. (2018). Phase-shift evolution of the thermally-induced refractive index grating in high-power fiber laser systems induced by pump-power variations. Opt. Express, 26 (15), 19489-19497. |
| [60] | Scarnera V., Ghiringhelli F., Malinowski A., Codemard C. A., Durkin M. K., and Zervas M. N. (2019). Modal instabilities in high power fiber laser oscillators. Opt. Express, 27 (4), 4386-4403. |
| [61] | Jauregui C., Stihler C., and Limpert J. (2020). Transverse mode stability. Ad. Opt. Photon., 12 (2), 420-484. |
| [62] | Jauregui C., Eidam T., Otto H. -J., Stutzki F., Jansen F., Limpert J., and Tünnermann A. (2012). Temperature-induced index gratings and their impact on mode instabilities in high-power fiber laser systems. Opt. Express, 20 (1), 440-451. |
| [63] | Jauregui C., Eidam T., Otto H. -J., Stutzki F., Jansen F., Limpert J., and Tünnermann A. (2012). Physical origin of mode instabilities in high-power fiber laser systems. Opt. Express, 20 (12), 12912-12925. |
| [64] | Jauregui C., Otto H. -J., Stutzki F., Jansen F., Limpert J., and Tünnermann A. (2013). Passive mitigation strategies for mode instabilities in high-power fiber laser systems. Opt. Express, 21 (16), 19375-19386. |
| [65] | Wang J., Gray S., Walton D., and Zentero L. (2008). Fiber fuse in high power optical fiber. Proc. Soc. Photo-Opt. Instrum. Eng., 7134, 71342E-1-71342E-9. |
| [66] | Domingues F., Frias A. R., Antunes P., Sousa A. O. P., Ferreira R. A. S., and André P. S. (2012). Observation of fuse effect discharge zone nonlinear velocity regime in erbium-doped fibres. Electron. Lett., 48 (20), 1295-1296. |
| [67] | Mary R., Choudhury D., and Kar A. K. (2014). Applications of fiber lasers for the development of compact photonic devices. IEEE J. Selected Topics Quantum Electron., 20 (5), 0902513. |
| [68] | Zhang H., Zhou P., Wang X., Xiao H., and Xu X. (2013). Fiber fuse effect in high-power double-clad fiber laser. Conf. on Lasers and Electro-Optics Pacific Rim (CLEO-PR), WPD-4. |
| [69] | Sun J., Xiao Q., Li D., Wang X., Zhang H., Gong M., and Yan P. (2016). Fiber fuse behavior in kW-level continuous-wave double-clad field laser. Chinese Phys. B, 25 (1), 014204. |
| [70] | Xiao Q., Tian J., Huang Y., Wang X., Wang Z., Li D., Yan P., and Gong M. (2018). Internal features of fiber fuse in a Yb-doped double-clad fiber at 3 kW. Chinese Phys. Lett., 35 (5), 054201. |
| [71] | Marcuse D. (1977). Loss analysis of single-mode fiber splices. Bell Syst. Tech. J., 56 (5), 703-718. |
| [72] | Shuto Y. (2014). Heat conduction modeling of fiber fuse in single-mode optical fibers. J. Photonics, 2014, 645207. |
| [73] | Kashyap R. (2013). The fiber fuse-from a curious effect to a critical issue: a 25th year retrospective. Opt. Express, 21 (5), 6422-6441. |
| [74] | Shuto Y. (2020). Cavity pattern formation and its dynamics of fiber fuse in single-mode optical fibers. J. Informatics Math. Sci., 12 (4), 271-288. |
| [75] | Todoroki S. (2014). Fiber Fuse: Light-Induced Continuous Breakdown of Silica Glass Optical Fiber. NIMS Monographs, Chap. 3, Springer, Tokyo. |
| [76] | Sikora E. S. R., McCartney D. J., Farrow K., and Davey R. (2003). Reduction in fibre reliability due to high optical power. Electron. Lett., 39 (14), 1043-1044. |
APA Style
Yoshito Shuto. (2022). Fiber Fuse Simulation in Double-Clad Fibers for High-Power Fiber Lasers. Journal of Electrical and Electronic Engineering, 10(1), 31-38. https://doi.org/10.11648/j.jeee.20221001.14
ACS Style
Yoshito Shuto. Fiber Fuse Simulation in Double-Clad Fibers for High-Power Fiber Lasers. J. Electr. Electron. Eng. 2022, 10(1), 31-38. doi: 10.11648/j.jeee.20221001.14
AMA Style
Yoshito Shuto. Fiber Fuse Simulation in Double-Clad Fibers for High-Power Fiber Lasers. J Electr Electron Eng. 2022;10(1):31-38. doi: 10.11648/j.jeee.20221001.14
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Download@article{10.11648/j.jeee.20221001.14,
author = {Yoshito Shuto},
title = {Fiber Fuse Simulation in Double-Clad Fibers for High-Power Fiber Lasers},
journal = {Journal of Electrical and Electronic Engineering},
volume = {10},
number = {1},
pages = {31-38},
doi = {10.11648/j.jeee.20221001.14},
url = {https://doi.org/10.11648/j.jeee.20221001.14},
eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.jeee.20221001.14},
abstract = {Rare-earth-doped optical fibers are one of the most promising solid-state lasers. In these fiber lasers, a cladding-pumping scheme using double-clad fibers is utilized to increase the overall conversion efficiency of pumping light. To maintain acceptable beam quality, the low-numerical aperture large-mode-area fibers is effective for the double-clad fibers because the effects of stimulated Raman scattering can be reduced via the corresponding reduction in the power density in the large fiber core. For the large-mode-area double-clad fibers, fiber fuse propagation was investigated theoretically by the explicit finite-difference method using the thermochemical SiOx production model. In the calculation, we assumed the fiber to be in an atmosphere and that part (40 μm in length) of the core was heated to a temperature of 2,923 K. The threshold power for the double-clad fiber with the core radius of 10 μm was 1.6 W at 1.080 μm and it was close to the experimental value. The power dependence of the velocity of fiber fuse propagation was calculated for the double-clad fibers with the core radius of 10 and 15 μm. The calculated velocities were in fair agreement with the experimental values observed in the input power range from 1 kW to 3.5 kW at 1.080 μm.},
year = {2022}
}
TY - JOUR T1 - Fiber Fuse Simulation in Double-Clad Fibers for High-Power Fiber Lasers AU - Yoshito Shuto Y1 - 2022/02/16 PY - 2022 N1 - https://doi.org/10.11648/j.jeee.20221001.14 DO - 10.11648/j.jeee.20221001.14 T2 - Journal of Electrical and Electronic Engineering JF - Journal of Electrical and Electronic Engineering JO - Journal of Electrical and Electronic Engineering SP - 31 EP - 38 PB - Science Publishing Group SN - 2329-1605 UR - https://doi.org/10.11648/j.jeee.20221001.14 AB - Rare-earth-doped optical fibers are one of the most promising solid-state lasers. In these fiber lasers, a cladding-pumping scheme using double-clad fibers is utilized to increase the overall conversion efficiency of pumping light. To maintain acceptable beam quality, the low-numerical aperture large-mode-area fibers is effective for the double-clad fibers because the effects of stimulated Raman scattering can be reduced via the corresponding reduction in the power density in the large fiber core. For the large-mode-area double-clad fibers, fiber fuse propagation was investigated theoretically by the explicit finite-difference method using the thermochemical SiOx production model. In the calculation, we assumed the fiber to be in an atmosphere and that part (40 μm in length) of the core was heated to a temperature of 2,923 K. The threshold power for the double-clad fiber with the core radius of 10 μm was 1.6 W at 1.080 μm and it was close to the experimental value. The power dependence of the velocity of fiber fuse propagation was calculated for the double-clad fibers with the core radius of 10 and 15 μm. The calculated velocities were in fair agreement with the experimental values observed in the input power range from 1 kW to 3.5 kW at 1.080 μm. VL - 10 IS - 1 ER -
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