Crystal structure and thermal and mid-infrared broadband luminescence characteristics of a novel Er,Dy:YAP crystal

Abstract

An Er,Dy:YAP laser crystal was grown successfully by the Czochralski method. The crystal structure and thermal and mid-infrared broadband luminescence characteristics are studied. The FWHM of XRC is 0.021°, indicating a high crystalline quality. The thermal conductivity of the as-grown crystal is 6.25 W m⁻¹ K⁻¹ at room temperature. The crystal exhibits broad absorption bands around 972 nm and 1550 nm due to the co-doping of Er³⁺. The emission band covers the 2.6–3.5 μm range with a width of nearly 900 nm, much wider than that of the Er:YAP crystal. The energy level lifetimes of Er:⁴I_11/2 and Er:⁴I_13/2 are fitted to be 20.06 and 50.49 μs, and the energy transfer efficiencies are calculated to be 97.68% and 98.69%, respectively. The results suggest that the Er³⁺ can be used as an effective sensitizer for Dy³⁺ in the YAP crystal, and the Er,Dy:YAP crystal is a novel ideal candidate material to realize wideband tunable laser emission around 3 μm.