Modelling the competition between photo-darkening and photo-bleaching effects in high-power ytterbium-doped fibre amplifiers
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We propose an innovative, fully space–time model to take into account the seed-dependent nature of ageing penalties in high-power ytterbium-doped fibre amplifiers. Ageing is shown to be based on the on-going competition between photo-darkening and photo-bleaching phenomena. Our approach is based on the natural interplay between the excited states of co-existing ytterbium pairs and colour centres in highly doped fibres, in the presence of thermal coupling between the closely spaced excited states. As initiated from IR photons, the excitation of colour centres up to the UV band is supposed to be governed by multi-photon absorption. The interactions of interest in the kinetics of photo-bleaching then take the form of highly efficient charge transfers, which imply the reduction of some fraction of the basically trivalent ions to their divalent state. Due to the activation of ytterbium pairs by means of energy transfer up-conversion, these interactions get more and more effective at elevated operating powers. Computational results using these principles actually help to fit our experimental data regarding seeding effects, as well as fully generic trends already evidenced in the literature. This gives a fine demonstration for the need to discriminate co-active pump and signal contributions. Our self-consistent, still simplified model then consists of a valuable tool to help for a deeper understanding of the ageing issues. Furthermore, considering higher-order ytterbium aggregates, this should open new routes towards more comprehensive models.
The Conseil-Régional-d’Aquitaine is greatly acknowledged. This work was made possible within the framework of the S.E.M.L. Route-des-Lasers, for supporting programmes dedicated to emerging applications in the laser industry. Many thanks also to Dr S. Vidal from ALPhANOV, for useful advice and comments.
- 7.W.P. Qin, Z.Y. Liu, C.F. Wu, G.S. Qin, Z. Chen, K.Z. Zheng, Multi-ion cooperative processes in Yb3+ clusters. Light Sci. Appl. 3, e193 (2014). http://www.nature.com-Open
- 9.J. Boullet, C. Vinçont, C. Aguergaray, and A. Jolly, ‘Regime-dependence of photo-darkening-induced modal degradation threshold in high power photonic crystal fiber amplifier,’ proc. ASSP– Boston-USA (2016)Google Scholar
- 13.A.A. Rybaltovsky, A.A. Umnikov, K.K. Bobkov, D.S. Lipatov, A.N. Romanov, M.E. Likhachev, V.B. Sulimov, A.N. Guryanov, M.M. Bubnov, E.M. Dianov, Role of oxygen hole centres in the photo-darkening of ytterbium-doped phosphor-silicate fibre. Quantum Electr. 43(11), 1037–1042 (2013)ADSCrossRefGoogle Scholar
- 15.H. Gebavi, S. Taccheo, D. Milanese, A. Monteville, O. Le Goffic, D. Landais, D. Mechin, D. Tregoat, B. Cadier, T. Robin, Temporal evolution and correlation between cooperative luminescence and photo-darkening in ytterbium doped silica fibers. Opt. Express 19(25), 25077–25083 (2011)ADSCrossRefGoogle Scholar
- 17.L. Skuja, H. Hosono, M. Hirano, Laser-induced color centers in silica, in Laser-Induced Damage in Optical Materials, vol. 4347, ed. by G.J. Exarhos, A.H. Guenther, M.R. Kozlowski, K.L. Lewis, M.J. Soileau (SPIE, 2001)Google Scholar
- 18.A.A. Rybaltovsky, K.K. Bobkov, V.V. Velmiskin, A.A. Umnikov, I.A. Shestakova, A.N. Guryanov, M.E. Likhachev, M.M. Bubnov, E.M. Dianov, The Yb-doped alumino-silicate fibers photo-darkening mechanism based on the charge-transfer state excitation. Proc. SPIE 8961, 896116-1 (2014)Google Scholar
- 19.K.K. Bobkov, A.A. Rybaltovsky, V.V. Velmiskin, M.E. Likhachev, M.M. Bubnov, E.M. Dianov, A.A. Umnikov, A.N. Guryanov, N.N. Vechkanov, I.A. Shestakova, Charge-transfer state excitation as the main mechanism of the photo-darkening process in ytterbium-doped alumino-silicate fibres. Quantum Electr. 44, 1129–1135 (2014)ADSCrossRefGoogle Scholar
- 20.R. Peretti, A.-M. Jurdyc, C. Gonnet, A new vision of photo-darkening in Yb-doped fibers. Proc. SPIE 8257, 825705-1 (2012)Google Scholar
- 23.T. Kitabayashi, M. Ikeda, M. Nakai, K. Himeno, K. Obashi, Population inversion factor dependence of photo-darkening of Yb-doped fibers and its suppression by high aluminium-doping. OFC/NFOE Conf. CD ROM (OSA, Washington-DC) OThC5B (2006)Google Scholar