title: Management of the high-order mode content in large (40 microm) core photonic bandgap Bragg fiber laser.
abstract: Very large-mode-area Yb(3+)-doped single-mode photonic bandgap (PBG) Bragg fiber oscillators are considered. The transverse hole-burning effect is numerically modeled, which helps properly design the PBG cladding and the Yb(3+)-doped region for the high-order mode content to be carefully controlled. A ratio of the Yb(3+)-doped region diameter to the overall core diameter of 40% allows for single-mode emission, even for small spool diameters of 15 cm. Such a fiber was manufactured and subsequently used as the core element of a cw oscillator. Very good beam quality parameter M(2)=1.12 and slope efficiency of 80% were measured. Insensitivity to bending, exemplified by the absence of temporal drift of the beam, was demonstrated for curvature diameter as small as 15 cm.
authors.affiliation: Xlim, UMR 6172 CNRS, University of Limoges 123 Avenue A. Thomas, 87060 Limoges, France.
authors.forename: D A
authors.initials: DA
authors.lastname: Gaponov
authors.forename: S
authors.initials: S
authors.lastname: Février
authors.forename: M
authors.initials: M
authors.lastname: Devautour
authors.forename: P
authors.initials: P
authors.lastname: Roy
authors.forename: M E
authors.initials: ME
authors.lastname: Likhachev
authors.forename: S S
authors.initials: SS
authors.lastname: Aleshkina
authors.forename: M Y
authors.initials: MY
authors.lastname: Salganskii
authors.forename: M V
authors.initials: MV
authors.lastname: Yashkov
authors.forename: A N
authors.initials: AN
authors.lastname: Guryanov