Amplifications in the S-, C- and L-bands using RE-ion doped short tellurite fibres with 980 nm and 800 nm excitation sources

Abstract

We report the results of emission and amplification in Tm³⁺- and Er³⁺-fibres for signal gain in the 1420 nm to 1600 nm wavelength range, which covers S-, C- and L-bands of silica fibre optical communication networks. The paper explains the mechanism for alleviating the pump excited state absorption (ESA) in Er-doped tellurite fibres for maximizing the pump inversion efficiency at 980 nm using the Ce-ions as a co-dopant and via the structural modification of TeO₂ glass using B₂O₃. The spectroscopic data and gain bandwidth of Er-doped fibres are reported in the C- and L-bands. Methods for enhancing gain in the S-band using the co-dopants (Tb³⁺, Yb³⁺) with 800 nm and 980 nm pumping schemes are also explained. The measured maximum relative gain in short fibres of 5 to 10 cm in length in C- and L-bands are: 30 dB and 15 dB, respectively. By comparison the internal gain in a 20 cm long Tm/Yb ion co-doped fibre pumped with a 980 nm source was 7 dB.