Three-wavelength switching in a cladding-pumped ytterbium-doped fiber laser

We present all-fiber double-clad Yb3+-doped fiber laser capable to switch between three different wavelengths. The fiber laser device consists of an array of three fiber Bragg gratings at 1064, 1080, and 1096 nm, spliced to one end of the double-clad Ytterbium-doped fiber, thus forming three laser cavities that share the same gain medium. The selection of a specific wavelength is realized by induced bend loss in the sections between gratings, thus allowing the control of the feedback at each specific wavelength. The device can operate separately at 1064, 1084 and at 1096 nm, with slope efficiencies at these three wavelengths of the order of 48% with respect to the launched pump power.