D. Richardson, J. Nilsson, and W. Clarkson, High power fiber lasers: current status and future perspectives, JOSA B, vol.27, pp.63-92, 2010.

J. Ballato, H. Ebendorff-heidepriem, J. Zhao, L. Petit, and J. Troles, Glass and process development for the next generation of optical fibers: A review, vol.5, 2017.
URL : https://hal.archives-ouvertes.fr/hal-01517484

M. J. Digonnet, Rare-Earth-Doped Fiber Lasers and Amplifiers, 2001.

V. Sudarsan, F. C. Van-veggel, R. A. Herring, and M. Raudsepp, Surface Eu 3+ ions are different than "bulk" Eu 3+ ions in crystalline doped LaF 3 nanoparticles, J. Mater. Chemi, vol.15, pp.1332-1342, 2005.

M. C. Gonçalves, L. F. Santos, and R. M. Almeida, Rare-earth-doped transparent glass ceramics, C. R. Chim, vol.5, pp.845-854, 2002.

B. Faure, W. Blanc, B. Dussardier, and G. Monnom, Improvement of the Tm 3+ : 3 H 4 level lifetime in silica optical fibers by lowering the local phonon energy, J. Non-Cryst. Solids, vol.353, pp.2767-2773, 2007.

J. F. Lupi, M. Vermillac, W. Blanc, F. Mady, M. Benabdesselam et al., Impact of cerium and lanthanum on the photo-darkening and photo-bleaching mechanisms in thulium-doped fibre, Opt. Mater, vol.72, pp.106-114, 2017.
URL : https://hal.archives-ouvertes.fr/hal-01598970

J. F. Lupi, M. Vermillac, W. Blanc, F. Mady, M. Benabdesselam et al., Steady photodarkening of thulium alumino-silicate fibers pumped at 1.07 µm: Quantitative effect of lanthanum, cerium, and thulium, Opt. Lett, vol.41, pp.2771-2774, 2016.
URL : https://hal.archives-ouvertes.fr/hal-01351037

Y. Mebrouk, F. Mady, M. Benabdesselam, J. B. Duchez, and W. Blanc, Experimental evidence of Er 3+ ion reduction in the radiation-induced degradation of erbium-doped silica fibers, Opt. Lett, vol.39, pp.6154-6157, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01081773

M. Vermillac, H. Fneich, J. F. Lupi, J. B. Tissot, C. Kucera et al., Use of thulium-doped LaF3 nanoparticles to lower the phonon energy of the thulium's environment in silica-based optical fibres, Opt. Mater, vol.68, pp.24-28, 2017.

C. Kucera, B. Kokuoz, D. Edmondson, D. Griese, M. Miller et al., Designer emission spectra through tailored energy transfer in nanoparticle-doped silica preforms, Opt. Lett, vol.34, pp.2339-2341, 2009.

I. Kasik, P. Peterka, J. Mrazek, and P. Honzatko, Silica optical fibers doped with nanoparticles for fiber lasers and broadband sources, Curr. Nanosci, vol.12, pp.277-290, 2016.

W. Blanc, C. Guillermier, and B. Dussardier, Composition of nanoparticles in optical fibers by Secondary Ion Mass Spectrometry, Opt. Mater. Express, vol.2, pp.1504-1510, 2012.
URL : https://hal.archives-ouvertes.fr/hal-00779864

D. 'acapito, F. Blanc, W. Dussardier, and B. , Different Er3+ environments in Mg-based nanoparticle-doped optical fibre preforms, J. Non-Cryst. Solids, vol.401, pp.50-53, 2014.

J. F. Lupi, M. Vermillac, S. Trzesien, M. Ude, W. Blanc et al., Gradual-time solution doping for the fabrication of longitudinally varying optical fibres, J. Lightw. Technol, vol.36, pp.1786-1791, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01804129

M. Vermillac, H. Fneich, J. Turlier, M. Cabié, C. Kucera et al., On the morphologies of oxides particles in optical fibers: Effect of the drawing tension and composition, Opt. Mater, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01981510

M. Vermillac, J. F. Lupi, F. Peters, M. Cabie, P. Vennegues et al., Fiber-draw-induced elongation and break-up of particles inside the core of a silica-based optical fiber, J. Am. Ceram. Soc, vol.100, pp.1814-1819, 2017.
URL : https://hal.archives-ouvertes.fr/hal-01351085

P. Schultz, Ultraviolet absorption of titanium and germanium in fused silica, Proceedings of the Eleventh International Congress on Glass, pp.4-8, 1977.

P. C. Schultz, Fused P 2 O 5 Type Glasses, vol.404, 1977.

A. Ghatak and K. Thyagarajan, An Introduction to Fiber Optics, 1998.

D. 'acapito, F. Maurizio, C. Paul, M. C. Lee, T. S. Blanc et al., Role of CaO addition in the local order around Erbium in SiO 2-GeO 2-P 2 O 5 fiber preforms, Mater. Sci. Eng. B, vol.146, pp.167-170, 2008.

S. A. Wade, S. F. Collins, and G. W. Baxter, Fluorescence intensity ratio technique for optical fiber point temperature sensing, J. Appl. Phys, vol.94, pp.4743-4756, 2003.

M. Weber, Part 1-Nonlinear optical properties/radiation damage, CRC Handbook of Laser Science and Technology, vol.3, 1986.

S. Jiang, T. Luo, B. C. Hwang, F. Smekatala, K. Seneschal et al., Er 3+-doped phosphate glasses for fiber amplifiers with high gain per unit length, J. Non-Cryst. Solids, vol.263, pp.364-368, 2000.