83 W efficient Nd-doped LMA fiber laser at 910 nm
Kilian Le Corre, H. Gilles, Sylvain Girard, Alexandre Barnini, Louanne Kervella, Pascal Guitton, Benoît Cadier, Thierry Robin, G. Santarelli, Mathieu Laroche
Abstract
We present here the development of ultra-low NA large mode area neodymium doped alumino-phospho-silica fibers with different clad-to-core ratios for high power laser emission around 910nm. This ratio is determinant in the competition between the 3-level transition at 910nm and 4-level transition of neodymium at 1060nm. The study shows that the 30/130µm (core/cladding) fiber was the most efficient, with a record output power of 83W at 910nm, yielding a 47% slope efficiency and a good beam quality (M²~1.5). Parasitic power at 1060nm was kept lower than 1W and no sign of roll-off was observed at maximum pump power.