Effect of BaF2 Variation on Spectroscopic Properties of Tm3+ Doped Gallium Tellurite Glasses for Efficient 2.0 μm Laser

Abstract

The effects of substitution of BaF2 for BaO on physical properties and 1. 8 μm emission have been systematically investigated to improve spectroscopic properties in Tm3+ doped gallium tellurite glasses for efficient 2.0 μm fiber laser. It is found that refractive index and density gradually decrease with increasing BaF2 content from 0 to 9 mol.%, due to the generation of more non-bridging oxygens. Furthermore, OH− absorption coefficient (αOH) reduces monotonically from 3.4 to 2.2 cm−1 and thus emission intensity near 1.8 μm in gallium tellurite glass with 9 mol.% BaF2 is 1.6 times as large as that without BaF2 while the lifetime becomes 1.7 times as long as the one without BaF2. Relative energy transfer mechanism is proposed. The maximum emission cross section and gain coefficient at around 1.8 μm of gallium tellurite glass containing 9 mol.% BaF2 are 8.8 × 10−21 cm2 and 3.3 cm−1, respectively. These results indicate that Tm3+ doped gallium tellurite glasses containing BaF2 appear to be an excellent host material for efficient 2.0 μm fiber laser development.

Enhanced 1.5 μm emission from Yb3+/Er3+ codoped tungsten tellurite glasses for broadband near-infrared optical fiber amplifiers and tunable fiber lasers

“…[13][14][15] In addition, the peak B, C and D at $450, 678 and 750 cm À1 are assigned to the symmetrical stretching or bending vibrations of Te-O-Te linkages at corner sharing sites, the anti-symmetric stretching vibrations of Te-O-Te linkages constructed by two un-equivalent Te-O bonds containing bridging oxygens (BO) in TeO 4 trigonal bipyramid and the symmetrical stretching vibrations of Te-O À and Te]O bonds with non-bridging oxygens (NBO) in TeO 3 trigonal pyramid and TeO 3+1 polyhedra, respectively. 15,16 Therefore, very diverse types of structural units in the present glass can provide various local ligand eld environments for Er 3+ ions in favor of inhomogeneous broadening of 1.5 mm emission band.…”