Management of the high-order mode content in large (40 microm) core photonic bandgap Bragg fiber laser.
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.
Gaponov
D A
DA
Xlim, UMR 6172 CNRS, University of Limoges 123 Avenue A. Thomas, 87060 Limoges, France.
Février
S
S
Devautour
M
M
Roy
P
P
Likhachev
M E
ME
Aleshkina
S S
SS
Salganskii
M Y
MY
Yashkov
M V
MV
Guryanov
A N
AN