Preparation Of Rare Earth Doped Germanium-based Heavy Metal Oxide Glass And The 2-3?m Emission Properties

The 2-3?m mid-infrared laser has extensive applications in laser radar,environmental detection,medical operation and optical communication et al,the laser materials with 2-3?m high efficient emission is the core and foundation of the mid-infrared laser.Now the research of the mid-infrared emission materials is mainly concentrated in crystal,silicate,fluoride and heavy metal oxide glass.Among those glasses,the germanate glass is suitable laser glass material because of it's good physicochemical properties,good mechanical properties,excellent thermal stability and broad transmission window,having favorable development prospect in ultra-short pulse laser.In this paper,the main purpose is studying the mid-infrared emission properties of rare-earth ions doped germanium-based heavy metal oxide glass,to provide theoretical basis and experimental basis for obtaining excellent mid-infrared laser glass medium.The dissertation includes the following six chapters.The chapter 1 is literature review.It introduces the principle of mid-infrared laser generation and relative rare-earth ions,then introduces the several kinds of glass matrix applied in mid-infrared band.At last,we put forward the main research contents in this paper.The chapter 2 is the experiment methods and the theory calculations,including the preparation procedures of germanate glass,the measurements of the relative properties and the theory analysis.The chapter 3 is the prepared and investigated of the two components of germanate glasses.The physicochemical properties and thermal stability of two kinds of glass were analyzed.The results show that both the two glass systems have good thermal properties.The chapter 4 is the mid-infrared emission properties of the rare-earth ions doped germanate glass?64GeO₂-9Ga₂O₃-10BaF₂-10LiF-7Y₂O₃?.Firstly,investigate the².9?m emission properties of the Dy³⁺/Yb³⁺co-doped germanate glass.Based on the measured absorption spectra,the J-O parameters were calculated and discusses.The radiative transition probability of Dy³⁺the is 63.94s^-1.the fluorescence intensity was not increased with the increase of Dy³⁺ion concentration,indicating that fluorescence quenching occurred in the Dy³⁺/Yb³⁺co-doped glass.An intense emission around³?m with the FWHM reaching to 322 nm was obtained in present glasses.The peak value of the Dy³⁺emission cross section reaches6.0×10^-21cm².and the good gain performances is proved by the gain coefficient.The energy transfer is verified by the overlap of the Yb³⁺emission cross section and the Dy³⁺absorption cross section.Finally,the energy transfer process is described by energy level diagram.Then we research the².7?m emission properties of the Er³⁺/Yb³⁺co-doped germanate glass.the J-O parameters were calculated and discusses.The radiative transition probability of Er³⁺is 34.84s^-1.Compared with the Er³⁺single doped glass,the fluorescence intensity is significantly increased in the Er³⁺/Yb³⁺co-doped germanate glass,and the fluorescence intensity is proportional to the Yb³⁺doping concentration,which indicated the fluorescence quenching did not occur in the glass.The peak value of the Er³⁺emission cross section reaches6.0×10^-21cm².The result shows that the prepared glasses has good gain performance.Finally,the energy transfer process among the Er-Yb is described by the Er³⁺and Yb³⁺ions energy level diagram.The chapter 5 is the mid-infrared emission properties of the rare-earth ions doped germanate-tellurite glass?70GeO₂-10TeO₂-10K₂O-5Nb₂O₅-5La₂O₃?.Firstly,investigatethe²?memissionpropertiesoftheTm³⁺/Ho³⁺co-doped germanate-tellurite glass.The J-O parameters were calculated and discusses.The radiative transition probability of Tm³⁺and Ho³⁺is 333.13s^-11 and 70.81s^-1,respectively.The co-doped glass with 1mol%Tm³⁺and 0.1mol%Ho³⁺has the maximum FWHM?373nm?,and the emission spectral is relatively flat,which is the result of the balance of the Tm³⁺:¹.85?m emission and Ho³⁺:²?m emission.It meet the requirement of broadband emission.The maximum emission cross section corresponding to Tm³⁺:³F₄?³H₆ and Ho³⁺:⁵I₇?⁵I₈ is 7.1×10^-21cm² and 1.4×10^-21cm²,respectively.The energy transfer mechanism is described by energy level diagram.The energy transfer among the Tm-Ho is quantitatively analyzed by the energy transfer microscopic parameters.Then we research the²?m emission properties of the Er³⁺/Ho³⁺co-doped germanate-tellurite glass.the J-O parameters were calculated and discusses.The radiative transition probability of Ho³⁺is 88.84s^-1.There is no emission in the Ho³⁺single doped glass.The²?m fluorescence intensity is proportional to the Er³⁺doping concentration,but the¹.55?m fluorescence intensity decreased gradually.Which indicated the efficient energy transfer from Er³⁺ion to Ho³⁺ions.The peak value of the Ho³⁺emission cross section reaches 3.9×10^-21cm².Finally,the energy transfer process in the co-doped glasses is described by the Er³⁺and Ho³⁺ions energy level diagram.The chapter 6 is the conclusion of this dissertation.Which summarizes the experimental results and points out the shortcomings of this paper.