Yb3+doped double-clad fiber laser based on fiber Bragg grating

Abstract

Fiber Bragg grating (FBG) was successfully fabricated in a Yb3+ doped double clad fiber with D-shaped inner-cladding by using phase mask method. Based on the FBG, a stable narrow line width double clad fiber laser was successfully demonstrated which resolved the output instability caused by mode-competition in common double-clad fiber lasers. The maximum output power is 570?mW at the wavelength 1058.2nm with 0.196nm line-band. Based on rate equations, the relationship between output power and pump power, the reflectivity of the FBG and the optimized length of the fiber were analyzed, which were in good agreement with the experimental results.