RT - Journal Article T1 - Investigation of Amplification Parameters in Q-switched Fiber Oscillator-Amplifier Systems JF - ijop YR - 2020 JO - ijop VO - 14 IS - 2 UR - http://ijop.ir/article-1-427-en.html SP - 155 EP - 162 K1 - Gain coefficient K1 - Saturation power K1 - End-pumped K1 - Side-pumped K1 - distributed K1 - Q-switched K1 - Fiber laser K1 - Master-oscillator power-amplifier. AB - In this paper, an analytical model is presented to compare the monolithic end-pumped and distributed side-pumped arrangements in the master oscillator power amplifier (MOPA) of Q-switched (QSW) double-clad (DC) ytterbium (Yb)-doped fiber system. First, the time-dependent rate equations are solved numerically by the finite difference method and the output pulse characteristics are obtained. For more amplifying, the laser pulse is injected into the amplifier and the gain and saturation coefficients are obtained by using the best fitting between the outcoming data from solving rate equations and the transient amplification relation, based on the least squares method (LSM). Finally, the dependence of pump power and dopant concentration on the cavity amplifying parameters are investigated. LA eng UL http://ijop.ir/article-1-427-en.html M3 10.52547/ijop.14.2.155 ER -