Numerical analysis and experimental results of output performance for Nd-doped double-clad fiber lasers

Numerical analysis is investigated for the high-power double-clad fiber las ers and experimental results using different microscope objectives for focu sing into a Nd-doped rectangular double-clad fiber also performed. The nume rical analysis includes dependence of output power on output mirror reflect ivity, absorbed pump power, loss, and fiber length and pump power distribut ion for the cases of one-end and two-end pumps with 20 dB/km loss. Calculat ed conversion efficiencies are 76.36%, 69.73%, and 63.84% for lossless, two -end pump, and one-end pump fiber lasers, respectively. Slope efficiencies from absorbed pump power/output powers measured using microscope objectives are 16.8%/182 mW, 53.8%/351 mW, 24.9%/1240 mW, and 13.9%/649 mW for magnif ications of 5 x, 10 x, 20 x, and 40 x, respectively. (C) 2000 Published by Elsevier Science B.V. All rights reserved.