Investigation On The Design And Infrared Luminescence Properties Of Active Ions Doped Silicate Glass Ceramics

Infrared lasers（1-3μm）have very important scientific and application values in the fields of gas monitoring,biomedicine,military countermeasures,and optical communications.Especially in the field of optical communication,with the requirements of fast information transmission processing and increasing bandwidth requirements,the requirements of infrared lasers are increasing.High-quality optical gain materials are essential to obtain infrared lasers with excellent performance.Therefore,people have been working on the development of infrared laser materials with better structures and properties.Silicate glass-ceramics have lower raw material cost,good physical and chemical properties,good mechanical properties,large space for structural optimization and performance control,as well as the advantages of both optical crystals and glass materials:they can provide a suitable crystal field environment like crystal materials,and have the advantage of simple preparation process of glass materials,and easy to make high power and large size devices.Therefore,the research on the structure and optical properties of active ions doping infrared optical functional silicate glass-ceramics are of great significance to obtain more excellent infrared laser materials.In this dissertation,based on the silicate system,a series of activated ion-doped silicate glass and glass-ceramics have been prepared by the traditional melt cooling-heat treatment method through reasonable composition design.The phase structure and the infrared fluorescence performance of the samples were also studied,the specific contents are as follows:1.Transition metal（Cr）and rare earth（Er）elements co-doped silicate glass and glass-ceramics containingβ-Zn₂Si O₄ crystals were prepared.The test results of the absorption and emission spectra of the sample show that the valence state of Cr changed during the heat treatment and crystallization process.A part of Cr³⁺ions was transformed into Cr⁴⁺ions occupying the nanocrystalline phase,and exhibit the broadband near-infrared emission when excited by an 808 nm pump source.The Cr³⁺ions always stay in the amorphous environment and can absorb the energy of the pump source and transfer it to the adjacent rare earth(Er³⁺ions)that is also in the amorphous environment to enhance the characteristic infrared emission of Er³⁺ions at 1530 nm.Besides,because the infrared emission centers of the activated ions(Cr⁴⁺,Er³⁺)are independent of each other,ultra-wideband near-infrared emission in the range of 1100 to 1700 nm was finally obtained in the glass-ceramic sample,which shows the potential application value in the field of optical communication.2.Transition metal（Cr）and rare earth（Ho）elements co-doped silicate glass and glass-ceramics containingβ-Zn₂Si O₄ crystals were prepared.The XPS test and the absorption and emission spectra of the samples were used to further study the valence state change of Cr element.The results show that the crystallization process of silicate glass matrix heat treatment promotes the valence state conversion of Cr³⁺→Cr⁴⁺.Besides,by properly designing the sensitization process between ions,efficient and controllable near-infrared to mid-infrared luminescence conversion was obtained from 950 nm to 1550 and 2050 nm.At the same time,ultra-wideband infrared emission in the range of 1200～2200 nm was also obtained,indicating the potential application of Cr³⁺/Cr⁴⁺/Ho³⁺ions co-doped silicate glass-ceramics as laser amplification materials in the field of optical communications.3.Ho³⁺/Yb³⁺co-doped oxyfluorosilicate glass and glass-ceramic containing Sr₂YF₇ nanocrystals were prepared.The state of the glass structure before and after crystallization was analyzed using Raman,XRD,and TEM,and the optical properties of the samples were tested using absorption and emission spectrometers.It was found that due to the precipitation of the Sr₂YF₇ nanophase in the amorphous environment,the environment with lower local phonon energy was caused.Two kinds of light emission phenomena corresponding to different energy transfer processes can be observed in glass and glass-ceramic.Significantly enhanced visible and infrared emission of Ho³⁺ions were obtained in the glass-ceramics.Further calculation results of absorption and emission cross-sections and gain coefficients show that nanostructured oxyfluorosilicate glass-ceramics containing the Sr₂YF₇crystal phase is an effective infrared laser material.