Dual effects of Nd3+ in Nd3+/Ho3+:CaLaGa3O7 crystal on 2.86 µm emission

Enhanced 2.86 µm emission corresponding to Ho3+: 5I6→5I7 was achieved in Nd3+/Ho3+ codoped CaLaGa3O7 crystal for the first time. The detailed spectroscopic properties and energy transfer mechanism of the as-grown crystal were investigated. The results show that the Nd3+ ion is not only a very good sensitizer in a Ho3+ doped CaLaGa3O7 crystal, but also an appropriate deactivated ion with efficient depopulation of the Ho3+: 5I7 level for enhancing the 2.86 µm fluorescence emission. And the energy transfer efficiency of Ho3+: 5I7→Nd3+: 4I13/2 is estimated to be 93%, which indicates that the self-termination effect for the 2.86 µm holmium laser is suppressed successfully in Nd3+/Ho3+: CaLaGa3O7 crystal. Besides, the thermal properties of Nd3+: CaLaGa3O7 crystal were also studied. In conclusion, the introduction of Nd3+ is favorable for achieving an enhanced 2.86 µm emission in Nd3+/Ho3+: CaLaGa3O7 crystal, which can act as a new promising candidate for mid-infrared lasers.