Midinfrared Emission Properties of Ho³⁺-doped Ge-Ga-S-CsI Glasses

A serial of chalcogenide glasses based on Ge-Ga-S-Csl system doped with the different Ho3+ ions were synthesized by melt-quenching technique. The properties of glasses including refractive indexes, absorption spectra, mid-infrared emission spectra and lifetimes of I-5(6) level of Ho3+ ions were measured. The Judd-Ofelt intensity parameters Omega(i)(i=2,4,6), oscillator strength f(cal), spontaneous transition probabilities A(rad) for Ho3+ ion were calculated by Judd-Ofelt theory. Multiphonon relaxation rates of the Ho3+ : I-5(5)-> I-5(6) and I-5(6)-> I-5(7) in Ge-Ga-S-Csl glasses were evaluated. Effect of Ho3+ ion concentration on the fluorescence spectra was investigated. The results indicate that the fluorescence under 900 nm excitation with peak wavelength at 2. 81 mu m and 3. 86 mu m are due to the Ho3+ : I-5(6)-> I-5(6) and I-5(6)-> I-5(7) transition, respectively. The intensity of the mid-infrared fluorescence are enhanced with the Ho3+ ion concentration increasing from 0. 5wt% to 1. 0wt%. Multiphonon relaxation rates are 29s(-1) and 34s(-1) for the Ho3+ : I-5(5)-> I-5(6) and I-5(6)-> I-5(7) transition, respectively.