The Development Of New Yb-doped Laser Glass

In order to get practical Yb3+-doped laser glasses with longer fluorescence lifetime, higher emission cross section, lower non-linear refractive index, good chem-physical property, the formation ranges, stability, absorption spectra and fluorescenct spectra.ect were investigated based on phosphate and borophosphae glasses system.This dissertation is composed of the Introduction, Review, Theory Analysis, Experiment Methods, Result & Discussion, and Conclusion Sections. Firstly, the background and the recent progress of the ytterbium and neodium- doped laser glasses were briefly introduced. Secondly, the advantages, the spectroscopic properties and the laser performance of the laser glasses, especially the ytterbium doped laser glasses were summarized .Finally, according to the investigation for the phosphate and the borophosphate laser glasses, some valuable results have been obtained.(1) The emission cross section, integrated absorption cross section and fluorescenct lifetime of laser glasses are defined as the key parameters of spectroscopic property. These properties depend strongly on the covalent bonding between rare-earth ions and oxygen ions in oxide glasses and the asymmetry in local structures surrounding rare-earth ions. The large difference of spectroscopic properties between silicate laser glasses and phosphate laser glasses mainly due to their structure differences. The long chain structure formed in phosphate glasses lead to a more asymmetry local field surrounding rare-earth ions and cause a larger o s.(2) Compared with the public information, 2 abs and o s of the laser glasses are good enough except that the lifetime is a little bit short.(3) In order to increase the thermal properties and mechanical properties of phosphate laser glasses, new series of glasses contain two network formers are preprared by introducing borate into phosphate glasses . IR Absorption and Raman spectra show that the borophosphate glasses have great differences of structure with phosphate glasses.(4) The amount of added borate is carefully measured to ensure transparent and chemical stable laser glasses are reached, besides, the amount of other compositions are also modified to avoid the shorten of lifetime. The result shows that the borophosphate glasses are superior to the phosphate glasses as Nd,Yb-doped laser glass materials.