Near-infrared emission properties and energy transfer of Tm3+-doped and Tm3+/Dy3+-codoped chalcohalide glasses

Near-infrared emission properties of Tm3+ in GeSe2-Ga2Se3-CsI glasses were investigated. The increase in emission intensity ratio I-1.47 mu m/I-1.22 mu m and the large increase in the lifetime of the Tm3+:H-3(4) level from 189 to 2480 mu s can be obtained as CsI concentration changes from 20% to 40%. These improved emission properties result from the appearance of I-containing structural units, which have low phonon energy and are located near the Tm3+ ions, dominating the multiphonon relaxation and cross relaxation. Radiative parameters of Tm3+ were calculated based on the Judd-Ofelt analysis. The potential use of Tm3+-doped GeSe2-Ga2Se3-CsI glasses for S-band fiber amplifiers was discussed. Additionally, the intensity and lifetime of 1.2, 1.3, and 1.47 mu m infrared fluorescence on Tm3+/Dy3+-codoped GeSe2-Ga2Se3-CsI glasses were studied, and the energy transfer mechanisms were discussed. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3040030]