A longitudinal and side-pumped single transverse mode double-clad fiber laser with a special silicone coating

Abstract A single transverse mode neodymium-doped double-clad cw fiber laser at λ = 1.06 μm with 286 mW output is described. A 25.0% slope efficiency with respect to absorbed pump power has been reached with longitudinal cladding-pumping at 805 nm. We describe here, what is to our knowledge the first side pumped double-clad fiber laser. Side-pumped operation has been realised with a prism-fiber coupler. An output power of 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 side-pumping is not necessary, because the silicone coating can simply be removed from the fiber. Saturation effects have been estimated.