JUDD–OFELT THEORY ANALYSIS AND SPECTROSCOPIC PROPERTIES OF Ho:LiNbO3

A series of Ho : LiNbO 3 crystals with various concentration of Ho 2 O 3 were grown by Czochralski technique. Transmittance spectrum, absorption spectrum and modified Judd–Ofelt approach have been used to investigate its spectroscopic properties. Ho concentrations in crystals were analyzed by an inductively-coupled plasma optical emission spectrometry (ICP-OE/MS). The results of the spectroscopic analysis of transition strengths for Ho ion in a series of Ho : LiNbO 3 crystals with various Ho content are reported. It is concluded that all the Ωλ values of the Ho ion decrease with increasing Ho content. For Ho (4 mol%): LiNbO 3, the obtained intensity parameters and radiative lifetime of the 5 I 5 level are: Ω2=5.75×10-20 cm2, Ω4=22.69×10-20 cm2, Ω6=14.10×10-20 cm2, and τ=4.08 ms respectively. The results showed that the Ho 2 O 3-codoped LiNbO 3 crystal increases the Ho ion radiative lifetimes, but has less influence on the fluorescence branching ratio.