Of Tm <sup> 3 + </ Sup> Ion-doped Transparent Glass Ceramic Spectroscopy Study

Luminescent materials based on lanthanide ions has been widely used as phosphors in lamps and display,components in optical communication,and active materials in laser devices. Crystalline and amorphous materials are frequently used as matrixes for lanthanide ions.As a mixture of crystal and glass,transparent oxyfluoride glass ceramics doped with lanthanide ions have attracted great attention since it was reported.The excellent combination of optical advantages of crystal host with chemical advantages of oxide glass matrix enhances the application of lanthanide doped optical materials significantly.Because the doped ions distribute both in nanocrystals and in glass matrix,two distinct local environments,crystal phase and glass phase,coexist in glass ceramics.This provides us a unique system for investigating spectral properties of doped ions in different local symmetry under identical conditions.In current paper,fluorescence from the ions in crystal phase and glass phase were investigated with selective excitation for Tm³⁺ doped transparent oxyfluoride glass ceramics containing LaF₃ nanocrytsals,it was found that the glass phase favors the blue up-conversion of Tm³⁺ when a single pulsed red light is applied.It is discussed that the dependency on temperature of fluorescence spectra and spectroscopic study of local thermal effect in transparent glass ceramicses containing nanoparticles.The paper is mostly divided into three parts:Part One:Spectroscopic properties of the ions sited in different local environments have been studied.It was found that the glass phase favors the blue up-conversion of Tm³⁺ when a single pulsed red light is applied.The most efficient up-conversion was obtained when the excited stated absorption is in resonant with excitation light.Ions in crystal phase and in glass phase were excited separately by tuning the excitation wavelength.Part Two:The selective excited spectra of Tm³⁺ doped transparent oxyfluoride glass ceramics at different temperatures were investigated,which shows that the line width,intensity of fluorescence and the spectra position all change with the temperature increasing in the range of 20K to 450K.The dependency on temperature of fluorescence spectra is influenced directly by the local environment. The fluorescence lifetime of active ions in glass phase ambient is less affected,while is largely affected in crystal phase ambient.The rule reliance upon the temperature of ³H₄ lifetime is studied under selective excitation as well as the behavior on the quadric exponential in the process of fluorescence decay.Part Three:Fluorescence dynamics processes depends on the local temperature of optical active ions,which is affected by the excitation laser,sample bath temperature and thermal conductivity of the sample. In this paper,local thermal effect for the fluorescence of triply ioned rare earth ions doped in nanocrystals is studied with laser spectroscopy and thermal conduction theory for transpartent oxyfluoride glass ceramics.