Experimental study of a Q-switched ytterbium-doped double-clad fiber laser

Abstract

We report an experimental characterization of a Q-switched operation of an all-fiber laser using $\sim $ 30 m of a double-clad ytterbium-doped fiber spliced to a piece of single-mode un-doped holey fiber. Loss modulation in the splicing point between the active and un-doped fiber due to a substantial coupling of light into lossy cladding modes stimulates pulsed operation of the fiber laser. Pulse energy of $\sim2.5$ $\mu$J was estimated and the repetition rate was measured in the range of 4-16 KHz.