A LONGITUDINAL AND SIDE-PUMPED SINGLE TRANSVERSE-MODE DOUBLE-CLAD FIBER LASER WITH A SPECIAL SILICONE COATING

A single transverse mode neodymium-doped double-clad cw fiber laser at lambda=1.06 mu m with 286 mW output is described. A 25.0% slope effic iency with respect to absorbed pump power has been reached with longit udinal cladding-pumping at 805 nm. We describe here, what is to our kn owledge the first side pumped double-clad fiber laser. Side-pumped ope ration has been realised with a prism-fiber coupler. An output power o f 143 mW and a slope efficiency of 21.2% with respect to absorbed pump power have been achieved. The delicate polishing of the fiber for sid e-pumping is not necessary, because the silicone coating can simply be removed from the fiber. Saturation effects have been estimated.