High bismuth-doped germanosilicate fiber for efficient E plus S-band amplification

Bismuth-doped germanosilicate fiber (BGSF), the active media of fiber amplifiers, has attracted widespread atten-tion. Here, we report a BGSF with a high bismuth concen-tration of 0.075 wt. % and achieve high-efficiency E + S-band amplification, which was prepared by the modified chemical vapor deposition (MCVD) process. The small signal absorp-tion (SSA) and unsaturated loss (UL) of BGSF at 1310 nm are 1.32 and 0.11 dB/m, respectively. The results show a record with only 45 m BGSF was created, to the best of our knowl-edge, which provides a maximum gain of 39.24 dB with an NF of 6.2 dB at 1430 nm under -20 dBm input signal power. (c) 2024 Optica Publishing Group