[1] Jauregui, C., Limpert, J. & Tünnermann, A. High-power fibre lasers. Nat. Photonics 7, 861–867 (2013). doi: 10.1038/nphoton.2013.273
[2] Eidam, T. et al. Femtosecond fiber CPA system emitting 830 W average output power. Opt. Lett. 35, 94–96 (2010). doi: 10.1364/OL.35.000094
[3] Eidam, T. et al. Experimental observations of the threshold-like onset of mode instabilities in high power fiber amplifiers. Opt. Express 19, 13218–13224 (2011). doi: 10.1364/OE.19.013218
[4] Jauregui, C. et al. Passive mitigation strategies for mode instabilities in high-power fiber laser systems. Opt. Express 21, 19375–19386 (2013). doi: 10.1364/OE.21.019375
[5] Smith, A. V. & Smith, J. J. Increasing mode instability thresholds of fiber amplifiers by gain saturation. Opt. Express 21, 15168–15182 (2013). doi: 10.1364/OE.21.015168
[6] Jauregui, C., Otto, H. J., Stutzki, F., Limpert, J. & Tünnermann, A. Simplified modelling the mode instability threshold of high power fiber amplifiers in the presence of photodarkening. Opt. Express 23, 20203–20218 (2015). doi: 10.1364/OE.23.020203
[7] Hansen, K. R. & Lægsgaard, J. Impact of gain saturation on the mode instability threshold in high-power fiber amplifiers. Opt. Express 22, 11267–11278 (2014). doi: 10.1364/OE.22.011267
[8] Robin, C., Dajani, I. & Pulford, B. Modal instability-suppressing, single-frequency photonic crystal fiber amplifier with 811 W output power. Opt. Lett. 39, 666–669 (2014). doi: 10.1364/OL.39.000666
[9] Laurila, M. et al. Distributed mode filtering rod fiber amplifier delivering 292W with improved mode stability. Opt. Express 20, 5742–5753 (2012). doi: 10.1364/OE.20.005742
[10] Otto, H. J. et al. Scaling the mode instability threshold with multicore fibers. Opt. Lett. 39, 2680–2683 (2014). doi: 10.1364/OL.39.002680
[11] Jauregui, C., Otto, H. J., Breitkopf, S., Limpert, J. & Tünnermann, A. Optimizing high-power Yb-doped fiber amplifier systems in the presence of transverse mode instabilities. Opt. Express 24, 7879–7892 (2016). doi: 10.1364/OE.24.007879
[12] Lægsgaard, J. Optimizing Yb concentration of fiber amplifiers in the presence of transverse modal instabilities and photodarkening. Appl. Opt. 55, 1966–1970 (2016). doi: 10.1364/AO.55.001966
[13] Beier, F. et al. Narrow linewidth, single mode 3 kW average power from a directly diode pumped ytterbium-doped low NA fiber amplifier. Opt. Express 24, 6011–6020 (2016). doi: 10.1364/OE.24.006011
[14] Otto, H. J. et al. Controlling mode instabilities by dynamic mode excitation with an acousto-optic deflector. Opt. Express 21, 17285–17298 (2013). doi: 10.1364/OE.21.017285
[15] Jauregui, C., Stihler, C., Tünnermann, A. & Limpert, J. Pump-modulation-induced beam stabilization in high-power fiber laser systems above the mode instability threshold. Opt. Express 26, 10691–10704 (2018). doi: 10.1364/OE.26.010691
[16] Jauregui, C., Eidam, T., Limpert, J. & Tünnermann, A. Impact of modal interference on the beam quality of high-power fiber amplifiers. Opt. Express 19, 3258–3271 (2011). doi: 10.1364/OE.19.003258
[17] Smith, A. V. & Smith, J. J. Mode instability in high power fiber amplifiers. Opt. Express 19, 10180–10192 (2011). doi: 10.1364/OE.19.010180
[18] Smith, A. V. & Smith, J. J. Steady-periodic method for modeling mode instability in fiber amplifiers. Opt. Express 21, 2606–2623 (2013). doi: 10.1364/OE.21.002606
[19] Jauregui, C. et al. Physical origin of mode instabilities in high-power fiber laser systems. Opt. Express 20, 12912–12925 (2012). doi: 10.1364/OE.20.012912
[20] Ward, B., Robin, C. & Dajani, I. Origin of thermal modal instabilities in large mode area fiber amplifiers. Opt. Express 20, 11407–11422 (2012). doi: 10.1364/OE.20.011407
[21] Naderi, S., Dajani, I., Madden, T. & Robin, C. Investigations of modal instabilities in fiber amplifiers through detailed numerical simulations. Opt. Express 21, 16111–16129 (2013). doi: 10.1364/OE.21.016111
[22] Hansen, K. R., Alkeskjold, T. T., Broeng, J. & Lægsgaard, J. Theoretical analysis of mode instability in high-power fiber amplifiers. Opt. Express 21, 1944–1971 (2013). doi: 10.1364/OE.21.001944
[23] Dong, L. Stimulated thermal Rayleigh scattering in optical fibers. Opt. Express 21, 2642–2656 (2013). doi: 10.1364/OE.21.002642
[24] Andermahr, N. & Fallnich, C. Modeling of transverse mode interaction in large-mode-area fiber amplifiers. Opt. Express 16, 20038–20046 (2008). doi: 10.1364/OE.16.020038
[25] Hansen, K. R., Alkeskjold, T. T., Broeng, J. & Lægsgaard, J. Thermally induced mode coupling in rare-earth doped fiber amplifiers. Opt. Lett. 37, 2382–2384 (2012). doi: 10.1364/OL.37.002382
[26] Ward, B. G. Modeling of transient modal instability in fiber amplifiers. Opt. Express 21, 12053–12067 (2013). doi: 10.1364/OE.21.012053
[27] Otto, H. J. et al. Temporal dynamics of mode instabilities in high-power fiber lasers and amplifiers. Opt. Express 20, 15710–15722 (2012). doi: 10.1364/OE.20.015710
[28] Stutzki, F. et al. High-speed modal decomposition of mode instabilities in high-power fiber lasers. Opt. Lett. 36, 4572–4574 (2011). doi: 10.1364/OL.36.004572
[29] Johansen, M. M. et al. Frequency resolved transverse mode instability in rod fiber amplifiers. Opt. Express 21, 21847–21856 (2013). doi: 10.1364/OE.21.021847
[30] Stihler, C., Jauregui, C., Tünnermann, A. & Limpert, J. Phase-shift evolution of the thermally-induced refractive index grating in high-power fiber laser systems induced by pump-power variations. Opt. Express 26, 19489–19497 (2018). doi: 10.1364/OE.26.019489
[31] Limpert, J. et al. Yb-doped large-pitch fibres: effective single-mode operation based on higher-order mode delocalisation. Light Sci. Appl. 1, e8 (2012). doi: 10.1038/lsa.2012.8
[32] Haarlammert, N. et al. Build up and decay of mode instability in a high power fiber amplifier. Opt. Express 20, 13274–13283 (2012). doi: 10.1364/OE.20.013274
[33] Erdogan, T. Fiber grating spectra. J. Light. Technol. 15, 1277–1294 (1997). doi: 10.1109/50.618322