Preparation And Research On Mid-infrared Optical Properties Of Pr³⁺ Doped Chalcogenide Glasses

Chalcogenide glasses possess the low phonon energy, the wide transmissionwindow, the high refractive index, the relatively good chemical and thermal stabilities,therefore are believed to be one of the candidate materials for IR field applications.Praseodymium has a very wide mid-infrared（MIR） spontaneous emission bandwhich covers from3.5to5.5μm, the large number of bands in the3⁵μm offers thepromise of lasers, amplifiers, and high brightness sources for remote sensing,countermeasures, and spectroscopic applications. However, the MIR property of Pr³⁺has tight relationship with the host material. In the past several years, fluorescenceemission at room temperature from Pr³⁺in the Ge-Ga-based selenide glass have beenreported, however in the Ge-Ga-based sulfide glass, most mid-infrared emissionsbeyond2.5μm from Pr³⁺wereobserved at cryogenic temperature（20K）.In the present work, several serial Pr³⁺-doped chalcohalide glasses （includingGGS-CdI₂series, GGS-PbI₂series and GGS-CdS series） were prepared. Theirabsorption spectra and emission spectra excited by2.02μm have been measured.⁴.6μm mid-infrared fluorescence emission from Pr³⁺in the sulfide glass issuccessfully observed at room temperature.Based on the absorption spectra, the Judd-Ofelt strength parameters Ωt（t=2,4,6）, transition probabilities （A）, radiative lifetimes（τrad）, fluorescence branching ratios （β） and emission cross-sections （σemi） have beencalculated. GGS-CdI₂glasses have relatively large rare-earth solubility, good thermalstability. therefore are the appropriate host glasses of mid-infrared laser.