Effect Of Aluminum And Borate Glass Structure On The Luminescence Properties Of Pr³⁺ And Er³⁺

Rare Earth doped laser glass is widely used in solid-state and fiber lasers due to its advantages of low cost and easy fabrication.Due to its excellent infrared transmittance,excellent mechanical properties and low phonon energy,aluminate glass is an ideal matrix material for rare earth doped laser glass.However,the development of aluminate glass has been hindered for a long time by the inherent disadvantages such as relatively poor thermal stability,narrow glass forming area and high melting temperature.In this paper,the influence of network-forming body and network-external body on aluminate glass and the influence of Matrix glass composition on the luminescence properties and concentration quenching of rare earth ions are studied,in order to improve the glass-forming property of aluminate glass,increase the concentration of rare earth ion doping and avoid the concentration quenching effect through the composition and structure design of aluminate glass.The main contents and conclusions of this thesis are as follows:（1）the properties of aluminates glass were improved by introducing boric oxide,Germanium oxide and gallium oxide into the traditional network form.The results of synchronous thermal analysis of the glass show that after adding the three network forms,compared with the pure aluminates glass,the thermal stability of glass,ΔT,was increased to 119°C,124°C and 142°C respectively.Compared with pure aluminate glass,the maximum phonon energy of aluminate glass will change when the network is added.Due to the vibration of the B-O bond in the borooxygen triangle and Borooxygen Tetrahedron,the maximum phonon energy of the borosilicate glass is increased to 918cm^-1.The maximum phonon energy of aluminogermanate glasses with Germanium oxide was increased to 780cm^-1due to the Q²group vibration of[Ge O₄]Tetrahedron.Due to the vibration of Ga-NBOs structure,the maximum phonon energy is about 660cm^-1.By studying the effect of Barium oxide,zinc oxide and sodium oxide on the thermal stability of aluminogallium glass,it is found that the addition of barium oxide and sodium oxide to the aluminogallium glass is beneficial to decrease the melting temperature and improve the thermal stability of the glass,when 8 mol%sodium oxide and 6 mol%barium oxide are introduced,the thermal stabilityΔT of glass reaches 138°C.The introduction of network oxide has no effect on the Raman Spectra of alumino-gallium glasses,which indicates that the basic structure of the glass network has not changed obviously.（2）The photoluminescence properties of Pr³⁺are greatly changed due to the difference of the maximum phonon energy of glass.By studying the luminescence properties of Pr³⁺in aluminate glasses with different network structures,it is found that the multi-phonon relaxation rate from ³P₀level to ¹D₂level is higher in the aluminoborate glasses with the highest phonon energy,the Pr³⁺visible photoluminescence mainly comes from the downward radiation transition of ¹D₂energy level.In the alumino-gallium glasses and alumino-germanate glasses with low phonon energy,the Pr³⁺visible light emission mainly comes from the ³P₀level downward radiation transition.The low phonon energy can reduce the non-radiative transition probability of Pr³⁺,and the radiation transition from ³P₀level down can form a four-level laser system,which is helpful to reduce the laser threshold and improve the laser efficiency.By studying the concentration quenching effect of Pr³⁺in different network structures,it is found that the concentration quenching process of Pr³⁺is related not only to the phonon energy of glass,but also to the basic structure of Matrix glass network,the doping concentration threshold of concentration quenching in aluminoborate and aluminogermanate glasses with intact glass network structure is higher than that in aluminogallium glasses.（3）B₂O₃-Na₂O binary borate glasses,which are the simplest and have abnormal phenomenon of Boron,are used as matrix materials to further discuss the influence of glass network structure on the concentration quenching of rare earth ions,the relationship between the structure of the glass network and the concentration quenching of Erbium ion was studied by adjusting the ratio of two components.The results show that when o/b is 0.16,[BO₃]will be completely transformed into[BO₄]unit in the glass network.By further adding o/b,the[BO₃]unit can not be continuously converted to the[BO₄]unit because[BO₄]can not be directly joined and should be separated by neutral or neutral ion groups.When O/B is 0.16,the structure of the glass network is the most complete,and the critical doping concentration of rare earth is the highest,which is 2 times and 1.5 times of that of other glass,respectively.