Effects of Ho~(3+)-doping concentration on the performances of resonantly pumped Ho:YAG ceramic lasers

摘要

In this paper we report on efficient lasing of a polycrystalline Ho:YAG ceramics at ～2.1 μm in-band pumped (~5I_8→ ~5I_7) by a Tm:fiber laser and discuss the effects of Ho~(3+)-doping concentration on laser performances. Lasing characteristics of 0.8 at.%, 1.0 at.%, 1.5 at.%, 2.0 at.% and 4.0 at.% Ho~(3+)-doped ceramic samples were evaluated and compared. Using an output coupler of 6% transmission, 9.4 W of output power at 2097 nm was generated with the 0.8 at.% doped Ho:YAG ceramic under 15.1 W of pump power, corresponding to a slope efficiency with respect to incident pump power of 64.0%. The prospects for improvement in output power and lasing efficiency via further optimization in Ho~(3+)-doping concentration are considered.