Infrared Spectral Properties Of NaYF₄?Na₅Lu₉F₃₂ Single Crystals Co-doped Rare-earth Ions

The mid-infrared solid-state lasers have attracted much attention because of their many potential applications,such as remote sensing,communications and military and many other fields.The market demand for mid-infrared laser crystals becomes more and more huge.The key point of this stage is mainly for large-size,high quality and high optical performance laser materials.Ho³⁺/Pr³⁺ co-doped NaYF₄ crystals,Er³⁺ single doped and Er³⁺/Yb³⁺ co-doped Na₅Lu₉F₃₂ crystals were grown by an improved Bridgman method.The main research for the luminescence properties of Ho³⁺ ions at ².85?m wavelength and the luminescence properties of Er³⁺ ions at ¹.5?m and ².7?m wavelength.Combined with the energy level structure and ionic interaction for Ho³⁺ and Er³⁺ ions,we analyzed the optical properties of materials from the XRD crystals structure,infrared transmission performances,infrared fluorescence emission characteristics,fluorescence decay lifetimes and other aspects.In chapter one,we introduced the application and development of laser crystals,and analyzed research situation and the related performances for infrared laser crystals.We also described the properties and advantages of fluoride crystals,including ?-NaYF₄ and Na₅Lu₉F₃₂ single crystals.The second chapter introduced the preparation process of fluoride crystals,and its properties and basic theory.In the third and chapters,we respectively analyzed the optical performances of Ho³⁺/Pr³⁺: ?-NaYF₄ crystal.According to Judd-Ofelt theory,we calculate the value of effective J-O parameters ?eff??₂,?₄,?₆?,radiative transition probability A,the radiative lifetime ?rad and fluorescence branch ratio ?.Research on the relationship between doping concentration and fluorescence intensity for ?-NaYF₄ single crystals with various Pr³⁺ concentrations.The optimum doping concentration of Pr³⁺ was 1.0 mol%.The results indicate that prepared fluoride single crystal has potential application value in the ².85?m mid-infrared solid-state lasers.The mid-infrared optical performance,fluorescence decay lifetimes and energy transfer for Er³⁺ ions which as the luminescence centers doped with NaYF₄ and Na₅Lu₉F₃₂ laser crystals were investigated in the chapter 4,chapter 5 and chapter 6 of this article.The ¹.5?m and ².7?m emission intensity of Er³⁺ ion reached the maximum as the doping concentration of Er³⁺ ion increased to 3.0mol%,and the ¹.5?m emission intensity of Er³⁺ ion reached the maximum as the doping concentration of Yb³⁺ ion increased to 6.0mol%.The results show that NaYF₄ and Na₅Lu₉F₃₂ fluoride single crystal have an extensive prospect in the ¹.5?m and ².7?m infrared solid-state lasers.Finally,the last chapter is the conclusion and prospect.In this paper,we summaries the experimental results,and describes the outlook for future research.