Abstract

Bismuth doped fiber amplifiers (BDFA) have been pumped with single mode 1190–1260 nm lasers to amplify signals over the O-band. We report here a BDFA using 915 nm multimode laser via an ytterbium fiber conversation stage. The conversion stage transforms 915 nm pump to single mode 1150 nm light used to pump BDF. This pump provides up to 3W of 1150 nm power over 20–70 °C with 0.25–0.2 electrical to optical conversion (wall-plug) efficiency. Compared to directly pumped BDFAs with 1195 nm single mode semiconductor laser(s) the 915/1150 nm pumping has superior optical performance and lower power consumption. The resultant BDFA provides >20 dB gain over 1255 to 1355 nm (17.6 THz) with a maximum gain of 29.3 dB and corresponding noise figure (NF) of 4.6 dB (λ = 1300 nm, Pin = −20 dBm). The BDFA has electrical power consumption of 8.1–9.6 W over 20–70 °C respectively. We also show the amplifier is suitable for high-speed data transmission by amplification of 50 Gbaud/s PAM-4 WDM signals over 30 km of G.652 fiber.