Coherent beam combining of 61 femtosecond fiber amplifiers

Ihsan Fsaifes (1) , Louis Daniault (1) , Severine Bellanger (1) , Matthieu Veinhard (1) , Jerome Bourderionnet (2) , Christian Larat (2) , Eric Lallier (2) , Eric Durand (3) , Arnaud Brignon (2) , Jean-Christophe Chanteloup (4, 1)

1 IP Paris - Institut Polytechnique de Paris
2 TRT - Thales Research and Technologies [Orsay]
3 Thales LAS France
4 LULI - Laboratoire pour l'utilisation des lasers intenses

We report on the coherent beam combining of 61 femtosecond fiber chirped-pulse amplifiers in a tiled-aperture configuration along with an interferometric phase measurement technique. Relying on coherent beam recombination in the far field, this technique appears suitable for the combination of a large number of fiber amplifiers. The 61 output beams are stacked in a hexagonal arrangement and collimated through a high fill factor hexagonal micro-lens array. The residual phase error between two fibers is as low as λ/90 RMS, while a combining efficiency of ∼50% is achieved.

Domaines: Optique / photonique

Ihsan Fsaifes, Louis Daniault, Severine Bellanger, Matthieu Veinhard, Jerome Bourderionnet, et al.. Coherent beam combining of 61 femtosecond fiber amplifiers. Optics Express, 2020, 28 (14), pp.20152. ⟨10.1364/oe.394031⟩. ⟨hal-02995221⟩