Spectroscopic Porperties Analysis Of Yb³⁺-Doped Graded Index Glass

Rare earth elements doped graded-index fiber is a kind of new structure gain fiber. Compared with other step index fiber which used generally at present, it has high quality of out beam, big mode field diameter, high efficiency of mode coupling and low bending loss.According to the theory of light propagation in graded-index fiber and technology of making graded-index fiber, this paper prepare graded-index fiber with Yb³⁺-doped laser glasses and ion exchanging technique. First of all, the paper choice proper components of glass, design formula of glass and prepare Yb³⁺-doped graded-index glass materials(SiO₂, B₂O₃, Al₂O₃, MgO, ZnO, Li₂O, Yb₂O₃) with melt quenching technology and ion exchanging technology. Then the paper got the index difference value, it is 0.01645, after ion exchanging technology by measuring index profile of graded-index glasses.Physical, thermal and optical properties of Yb³⁺-doped laser glasses were measured at room temperature in this paper. Spontaneous emission transition probabilities(742.5s^-1), absorption cross section( 975nm, 0.89pm²) and emission cross section(1001nm, 0.466pm²) were calculated by means of Judd-Ofelt and McCumber theory.The results showed that silicate glasses have a high doping ratio for Yb³⁺ ion, good chemical stability, good thermal stability, good optical properties and excellent Li⁺-Na⁺ ion-exchanging properties, so it is an attractive optical fiber materials.