Dual function of Nd3+ in Nd,Er:LuYSGG crystal for LD pumped ~3.0 μm mid-infrared laser.

Enhanced ~3.0 μm emission corresponding to Er3+:4I11/2→4I13/2 was achieved in Nd3+/Er3+ co-doped Lu0.15Y2.85Sc2Ga3O12 (abbr. as Nd,Er:LuYSGG) crystal under 808 nm pumping. As compared with Er:YSGG crystal, the absorption pump efficiency of Nd,Er:LuYSGG crystal is greatly improved and thus ~3.0 μm emission is enhanced by 2.2 times owing to the sensitization of Nd3+, at the same time, Nd3+ as deactivator quenches ~1.5 μm emission from Er3+:4I13/2 level and thus inhibit the self-termination effect successfully. The energy transfer efficiencies of Nd: 4F3/2→Er: 4I11/2 and Er: 4I13/2→Nd:4I15/2 are estimated to be 91.6% and nearly 100%, respectively. These results indicate that the introduction of Nd3+ is very helpful for achieving ~3.0 μm laser in Nd,Er:LuYSGG crystal.