Spectroscopic properties of Er3+ doped TeO2–BaO (Li2O, Na2O)–La2O3 glasses for 1.5-μm optical amplifiers

This paper reports on the optical spectroscopic properties and thermal stability of Er3+-doped TeO2-BaO (Li2O, Na2O)–La2O3 glasses for developing 1.5-μm fiber amplifiers. Upon excitation at 977 nm laser diode, an intense 1.53-μm infrared fluorescence has been observed with a broad full width at half maximum (FWHM) of about 60 nm for the Er3+-doped TeO2–BaO (Li2O, Na2O)–La2O3 glass with 10 mol% of BaO. The calculated fluorescence lifetime and the emission cross-sections of the 1.53-μm transition are 2.91 ms and ∼9.97 × 10−21cm2, respectively. It is noted that the gain bandwidth, σe × FWHM, of the TeO2–BaO–La2O3–Er2O3 glass is about 600, which is significantly higher than that in silicate and phosphate glasses. Meanwhile, it is interesting to note that the TeO2–BaO–La2O3–Er2O3 glass has shown a high glass thermal stability and good infrared transmittance. As a result, TeO2–BaO (Li2O, Na2O)–La2O3 glass with 10 mol% of BaO has been considered to be more useful as a host for broadband optical fiber amplifier.