Investigation of Er3+-Doped Phosphate Glass for L+ Band Optical Amplification

In this work, Er3+-doped phosphate glass with good flatness of the emission spectrum of the L+ band was prepared by optimizing the content of BaO. The absorption and emission spectra were measured. Increase of BaO content is conducive to the broadening of the emission spectrum in the L+ band. The dependence of flatness with Raman intensity has been shown by linear fitting. The results show that B31 sample has best flatness of the emission spectrum in the L+ band. It is showed that the largest emission cross-section at 1630 nm is 0.0529 × 10-20 cm2 and higher than other Er3+-doped phosphate glass. Decay curves of the 4I13/2 level were measured and the longest fluorescent lifetime is 10.18 ms and longer than other glass except germinate glass. The broadening of the Er3+-doped phosphate glass spectrum of the L+ band has been achieved successfully, which provides a reference for the material of optical amplifiers.