Modeling and optimization of high-power Nd3+-Yb3+ codoped fiber lasers

Abstract

High-power continuous-wave Nd3+-Yb3+ codoped fiber lasers (NYDFL) are analyzed, based on a rate-propagation equations model. The model takes into account energy transfer between Nd3+-Yb3+, as well as cross relaxation between Nd3+ions, and contributions from high-order modes to the amplified spontaneous emission (ASE). Examples of cladding-pumped NYDFLs with distributed Bragg reflector (DBR) at either end are presented. We demonstrate the optimal laser design by considering the effects of the Nd3+-Yb3+ concentrations, pump wavelengths multiplexing, output mirror reflectivity, and the laser wavelength. Approximate quasi-analytical solutions are shown to be in good agreement with the exact numerical solutions of the rate equations for practical conditions. © 2006 IEEE.