Multimode fiber lasers based on Bragg gratings and double-clad Yb-doped fibers

We have realized a set of multimode lasers based on a double-clad Yb-doped fiber and Bragg gratings written on a graded-index multimode fiber. Efficient laser operation in the spectral range of 1.03-1.09 μm has been observed. Spectral characteristics of the laser emission have been investigated.