title: Beam cleanup in a self-aligned gradient-index Brillouin cavity for high-power multimode fiber amplifiers.
abstract: We propose a beam cleanup setup to convert a multimode beam into a single-mode beam by use of the Brillouin effect in a multimode gradient-index (GI) fiber. Phase conjugation and beam cleanup regimes in highly multimode fibers are discussed, and the self-aligned GI fiber Brillouin cavity is presented. We report a preliminary conversion from an M2=6.5 beam into an M2=1.3 beam with 31% efficiency.
authors.affiliation: Thales Research and Technology-France, Palaiseau. laurent.lombard@iota.u-psud.fr
authors.forename: L
authors.initials: L
authors.lastname: Lombard
authors.forename: A
authors.initials: A
authors.lastname: Brignon
authors.forename: J P
authors.initials: JP
authors.lastname: Huignard
authors.forename: E
authors.initials: E
authors.lastname: Lallier
authors.forename: P
authors.initials: P
authors.lastname: Georges