Dopant occupancy and optical properties of Ho3+ in Hf: Ho: LiNbO3 crystal

A series of Hf: Ho: LiNbO3 crystals with a fixed concentration of Ho2O3(0.5 mol%) and varied HfO2 were grown. The effect of Hf4+ ion on the dopant occupancy and optical properties of Ho3+ ion in Hf: Ho: LiNbO3 crystals were investigated. To detect the optical properties of the crystals, X-ray diffraction (XRD) patterns and UV-vis spectra were registered. Furthermore, the Judd-Ofelt spectroscopic analysis was employed for the Hf: Ho: LiNbO3 crystals. The results showed that the Ω2 and Ω6 parameters increased with the increase of Hf4+ concentration. Notably, HfO2 incorporation exhibited an intensive effect on the radiative lifetime, but less influence on fluorescence branching ratios.