Investigations on bismuth and aluminum co-doped germanium oxide glasses for ultra-broadband optical amplification

The broadband luminescence covering 1.2–1.6 μm was observed from bismuth and aluminum co-doped germanium oxide glasses pumped by 808 nm laser at room temperature. The spectroscopic properties of GeO2:Bi,Al glasses strongly depend on the glass compositions and the pumping sources. To a certain extent, the Al3+ ions play as dispersing reagent for the infrared-emission centers in the GeO2:Bi,Al glasses. The broad infrared luminescence with a full width at half maximum larger than 200 nm and a lifetime longer than 200 μs possesses these glasses with the potential applications in broadly tunable laser sources and ultra-broadband fiber amplifiers in optical communication field.