Collective synchronization and phase locking of fs fiber amplifiers: Requirements and potential solutionsL. Lombard, C. Bellanger, G. Canat, L. Mugnier, F. Cassaing, V. Michau, P. Bourdon and J. PrimotEur. Phys. J. Special Topics, 224 13 (2015) 2557-2566DOI: https://doi.org/10.1140/epjst/e2015-02565-9