The Preparation And Properties Of Yb³⁺-doped Fluorophosphate Glasses With High Gain Coefifcient

The glass system doped with trivalent ytterbium ions （Yb3+） is considered to be the best gainmedium candidate for the fber lasers owing to the longer fuorescence lifetime, higher emissionefficiency and stronger emission intensity. Among Yb3+-doped laser medium glasses,fluorophosphate glasses show great promising future due to their excellent properties, includinglow phonon energy, low nonlinear refractive index, wide transmission range from UV to NIR,high solubility for rare earth ions as well as good physical and chemical stability.With the aiming to get practical Yb³⁺-doped fluorophosphate laser glasses which have highgain coeffcient and good chemical physical properties, two systems FPZ（P2O5-ZrF4-RF2） andPAC（P₂O₅-AlF₃-RF₂） were studied. The emission cross-section and thermal processing stabilityof the FPZ were improved by the introduction of HMO. The long fluorescence lifetime of thePAC were obtained by changing the kind and ratio of the alkali metal and alkaline earth metalfluoride. The water-free of the FP were obtained by improving the melting process. Thevaluebale results of this thesis are as follows:1. Summarize and put forward the theory of the impact of the gain performance factors. Theexperiments demonstrated the feasibility and correctness of the theory. The parameters of theglass with high gain coeffcient were obtained by simulation.2. A new kind of FPZ glass, with excellent gain performance and high thermal stability, isprepared by introducing HMO. The result shows that emission cross-sections of the sampleFPZ-6are1.29pm², and has a lifetime of1.51ms and theΔT （T_x-T_g） of179oC.3. The influence of the alkali metal fluoride and alkaline earth metal fluoride to spectroscopicproperties of PAC glass were studied. The result shows that emission cross-sections of the PAC-5are0.80pm², and has a lifetime of2.25ms and the gain coeffcient of1.8ms×pm².4. The influence of the melting process to hydroxyl concentration of FP glass was studied byEDX and Raman spectrum. The water-free FP glass were obtained with emission cross-sectionsof0.82pm²and lifetime of2.25ms.