Threshold characteristics of linear cavity Yb3+-doped double-clad fiber laser

The threshold characteristics of linear cavity Yb3+-doped double-clad fiber laser have been studied theoretically and experimentally. By solving rate equations, the expression for threshold pump power is obtained. The effects of fiber length, mirror reflectivity, pump wavelength, laser wavelength and Yb3+ concentration on threshold pump power are discussed. Then, the Yb3+-doped double-clad fiber laser with linear cavity is developed. By using various output couplers, threshold pump power has been measured. The experimental results are in accord with theory.