Preparation And Performance Of New Mid-infrared Tellurite Glasses

In recent years,the mid-infrared laser in 2?5 ?m wave band has received widespread attention.Mid-infrared optical communication transmission has great potential for application in the communications industry,national defense,satellite remote sensing and other fields.At present,the research of mid-infrared laser materials mostly focus on the traditional rare-earth ions doped glass,glass ceramics,and single crystal,as well as nanocrystal-glass composite which is a new kind of matrix material.However,these materials all have their own defects which limit their application and development to a certain extent.This dissertation illustrates how to design two systems of tellurite glass based on simple preparation,low melting point,good mechanical properties and low phonon energy of tellurite glass,as well as reducing the effect of hydroxyl groups in glass.One is to prepare an environmentally friendly tellurite glass system with low melting point that improves the controllable range of the glass temperature of the nanocrystal-glass mid-infrared composite material.The other is to prepare a new rare-earth ions doped and mid-infrared fluorescent glass system which has simple process and can effectively reduce the hydroxyl group concentration in tellurite glass.The dissertation illustrates that a low-melting glass system with the matrix of TeO2-ZnO-Na2O-Li2O-B2O3 has been developed.The glass can be completely melted into aliquid at 450?,which greatly reduces the doping temperature of nanocrystal and widens controllable doping temperature range.Through the test and analysis of the glass structure and physical properties(density,refractive index,and thermal properties)as well as the transmittance performance of the glass in the mid-infrared under different composition ratios,effects of changes in the content of various components on the various properties of the glass are clarified to provide reference for the optimization of glass components and the selection of best composition ratio.Finally,the glass system provides a basic material reference for the development of new mid-infrared nanocrystalline-glass composite material.Cl-is added to the tellurite glass system which is co-doped with Yb3+/Er3+,to prepare a new chlorotellurite glass system.Through the chemical reaction of Cl-with the hydroxyl group in the glass,the gas is generated to reduce the concentration of the hydroxyl group in the glass and enhance the fluorescence output.Structural and thermal performance tests are conducted on glass samples to understand the effect of YCl3 content on glass structure and thermal performance.The effect of the concentration of Cl-in the glass on the removal of hydroxyl group and on the fluorescence output strength and fluorescence lifetime are analyzed,through calculating the concentration of hydroxyl groups in the glass based on the transmission spectrum and comparing the fluorescence spectra with fluorescence attenuation curves.By changing the type of chloride,the same tests are performed to analyze whether the cations in the chloride will affect the structure and thermal properties,as well as luminescence properties of the glass.According to the results of tests and analyses,the feasibility and problems of the glass system are clarified,providing ideas for the optimization of the glass and a new reference for the direction of design on the mid-infrared fluorescent glass system.