Pirri Angela, Toci Guido, Alderighi Daniele, Vannini Matteo
Istituto di Fisica Applicata Nello Carrara, Consiglio Nazionale delle Ricerche IFAC-CNR, Via Madonna del Piano 10C, 50019 Sesto Fiorentino, FI, Italy.
Opt Express. 2010 Aug 2;18(16):17262-72. doi: 10.1364/OE.18.017262.
We report the behavior of two Yb(3+) doped ceramics (i.e. 10% at. and 20% at.) under quasi-continuous wave laser pumping. Two different behaviors are found depending on the density of Yb(3+) in the excited level. Experimental results show that at low population inversion density, the maximum output power and the efficiency are almost independent on the doping concentration. In particular, an output power as high as 8.9 W with a corresponding slope efficiency of 52% with respect to the injected pump power was reached with the 20% at. sample. Conversely, at high population inversion densities, the 20% doped sample shows a sudden decrease of the laser output for increasing pump power, due to the onset of a nonlinear loss mechanism. Finally, we report a comparison of the experimental results with numerical simulations for the evaluation of the inversion density and of the temperature distribution.
我们报道了两种掺Yb(3+)陶瓷（即原子分数为10%和20%）在准连续波激光泵浦下的行为。根据激发态Yb(3+)的密度发现了两种不同的行为。实验结果表明，在低粒子数反转密度下，最大输出功率和效率几乎与掺杂浓度无关。特别是，原子分数为20%的样品达到了高达8.9 W的输出功率，相对于注入泵浦功率的相应斜率效率为52%。相反，在高粒子数反转密度下，由于非线性损耗机制的出现，20%掺杂的样品随着泵浦功率的增加激光输出突然下降。最后，我们报道了实验结果与数值模拟的比较，以评估反转密度和温度分布。
