Preparation And Investigation On Mid-infrared Luminescence Properties Of Pr³⁺-doped Chalcogenide Glass Fiber

3?5 ?m mid-infrared?MIR?wavelength located in the transmission window in the air,covers molecule characteristic absorption or vibrational energy band of most gases,liquids and solids,are of great interest in military,biological detection and medical,such as infrared radiation simulation of tactical missile tail flame,laser radar for human eye safety,fine operation in surgery and so on.To date the main way to obtain the mid-infrared bright sources is through the rare earth ion doped chalcogenide glasses and fiber,on the basis of the previous researches,with Pr³⁺-doped chalcogenide glass and fiber as the research object,the optical parameters of different concentration Pr³⁺ doped chalcogenide glass were calculated according to the Judd-Ofelt theory,the effect of Pr³⁺ concentration on the intensity of mid-infrared luminescence was discussed.Improved purification process was applied in the fabrication of fiber preform,the spectrum feature test and fiber drawing were investigated,which provides theoretical and experimental foundation for the realization of 3?5 ?m chalcogenide glass fiber laser.In chapter one,the main generating methods and application of 3?5 ?m mid-infrared bright sources were introduced,The author mainly illustrated the research on Pr³⁺-doped chalcogenide glass fiber,the present problems and development trend of rare-earth ion doped fiber were analyzed,and the research contents,purpose and significance of this thesis are put forward.In chapter two,mainly introduced the theoretical foundation of spectrum parameter calculation,including Judd-Ofelt theory,Futchbauer-Ladenburg theory,Mc-Cumber theory and energy transfer theory,etc.In chapter three,the testing equipments and methods were elaborated specifically,mainly consist of the preparation process of chalcogenide glass and the measurement methods of optical properties.In chapter four,the optical properties of Pr³⁺ doped Ge-As-Ga-Se chalcogenide glass were studied,mainly including the physical properties,absorption and mid-infrared luminescence spectrum.Judd-Ofelt theory theory was utilized to calculate the relevant spectrum parameters,the effects on local structure of Pr³⁺ ions were investigated with the increase of Pr³⁺ concentration.In chapter five,multistage distillation purification process and fabrication of 0.1 mol% Pr³⁺-doped Ge-As-Ga-Se glass fiber were illustrated.The author mainly investigated the optical properties of Pr³⁺-doped Ge-As-Ga-Se glass fiber and tested the infrared near-field distribution and fiber loss,the florescence output at 3.7⁵.5 ?m was obtained,and the influence of fiber loss on the transmission efficiency was analyzed.In the end,the achievements of this work and improvements should be done in the future work are outlined.