Investigation Of The New Band Optical Properties Of Rare Earth Ions Doped Tellurite Glasses And Fiber

Fiber lasers operating in visible wavelength region (380-780nm) and mid-infraredwavelength region (~3μm) have attracted great attention due to their potential applications invarious fields, including communications, medical treatment, national defense and so on.However, up to now, these lasers have been achieved only by using fluoride glass fiber as gainmedium, and some practical application problems still have not been solved. Therefore it is ofgreat significance to develop tellurite glass with stable chemical properties instead of fluorideglass to realize the laser output in these wavelengths.This research has a guiding role for the development of fiber laser gain material in newwavelength region by optimizing the visible and mid-infrared spectroscopic properties of rareearth doped tellurite glasses and optical fiber performance through exploring the fiberpreparation technology. The results can be summarized as follows:For mid-infrared laser, the influence of OH-content on emssions at1.5μm and2.7μmwas investigated in different phonon energy glass matrixes. The results show that both theemission at2.7μm and quenching effect of OH-content in low phonon energy glasses arehigher than those in high phonon energy glasses. In addition, we also discussed theenhancement of2.7μm emission intensity of Er3+ions through codoping with Pr3+or Tm3+.For visible laser, visible spectral properties of various rare earth ions(Tb3+、Sm3+、Pr3+)doped tellurite glasses were investigated. The results show that the different cross relaxationprocesses of three rare earth ions lead to their different concentration quenching, and theoptimum concentration is1.5mol%for Pr3+,0.5mol%for Sm3+,3mol%for Tb3+. In addition,the stimulated absorption and stimulated emission were compared for rare earth dopedtungsten tellurium lanthanum glasses. The stimulated absorption cross section at bluewavelength of Pr3+is the largest, and the stimulated emission cross section is one order ofmagnitude larger than that of Sm3+in tellurium tungsten lanthanum glasses, therefore Pr3+ions is the best choice to achieve red laser. For Tb3+ions, although the absorption crosssection is small, but it can be highly doped, which makes it more suitable for the green laseroutput. For tellurite glass fiber preparation technology, we explored the preform fabricationprocess by using suction casting method, and further investigated fiber drawing technologyand fiber properties. Finally, step multimode tellurite glass fiber with standard size, stablephysical and chemical properties, good mechanical properties was prepared. The backgroundloss of the fiber at1310nm was measured to be4.44dB/m using the cutback method, andcould be further reduced by improving the purity of raw material. Therefore, this glass fiber isa suitable gain material for optical fiber amplifier and lasers.