Research On Yb-Doped Silicate Glass And Photonic Crystal Fiber

Fiber laser which has advantages of small size, high efficiency etc has aroused our great interest. Photonic crystal fiber, as a new kind of special fiber, possesses more novel optical properties than the traditional fiber. Special photonic crystal fiber that doped with a little mount of rare earth oxides is the best choice for the ultrahigh power laser.Because the structure of Yb³⁺ ions is very simple without fluorescence quenching and excited state absorption in the theory, it is very suitable to be used as activate particle in the laser materials for high-power laser. Recently, Yb³⁺-doped silicate laser glass has been hot topic because of its advantages such as simple preparation technology, easy to change composition of glass.In this thesis, Yb³⁺-doped glass is prepared by high-temperature melting method, and Yb³⁺-doped glass can meet the need of the Yb³⁺-doped fiber laser through theoretical and experimental study. The main context includes:Firstly, Yb³⁺-doped silicate laser glass that has heterogeneity is prepared by high-temperature melting method, the refractive index, density and other physical performance parameters of silicate glass were tested, and the spectra properties of absorption and fluorescence were tested,too.Secondly, The physical properties of Yb³⁺-doped glass is researched. The impact of silicate glass composition on glass density, refractive index, spectrum properties is analyzed.Thirdly, The performance parameters of Yb³⁺-doped silicate glass such as absorption cross section, integral absorption cross-section, stimulated emission cross section spectra are calculated by F-L theory and MC theory. The impact of Yb³⁺ ions doping concentration and glass composition changes on the glass spectrum are analyzed. Finally, Yb³⁺-doped photonic crystal fiber is realized using the prepared silicate laser material, and its geometry parameters, numerical aperture, mode field diameter and absorption spectra is tested.