Tunable ytterbium-doped fiber laser based on a mechanically induced long period holey fiber grating

We describe a tunable double-clad Yb-doped fiber laser based on a long period fiber grating mechanically induced in a section of single mode holey fiber inserted into the laser cavity. The mechanically induced long period holey fiber grating acts as a wavelength-selective fiber filter whose central wavelength, linewidth, and strength can be tuned by changing the period, the length of the grating, and the applied pressure. The fiber laser gives a similar to 12.6 nm tuning range, from similar to 1079.4-1092 nm, with slope efficiencies of 18.7-26.3% at this wavelength range, with respect to the launched pump power. (c) 2007 The Optical Society of Japan