Efficient Fibre Amplifiers Based on a Highly Er 3+ /Yb 3+ Codoped Phosphate Glass-Fibre

Highly Er 3+ /Yb 3+ -codoped single-mode phosphate glass fibre is fabricated by the rod-in-tube technique. The performances of high-concentration Er 3+ /Yb 3+ -codoped phosphate glass fibre amplifiers are investigated and discussed. An efficient optical fibre amplifier with a gain of 12.6 dB based on a 3.0 cm long Er 3+ /Yb 3+ -codoped phosphate glass fibre is demonstrated under a dual-pump configuration with two 976 nm fibre-pigtail laser diodes, which make it attractive for compact Er 3+ -doped fibre amplifiers. The obtained noise figures of signal wavelength from 1525 to 1565 nm are less than 6.0 dB. Gain saturation behaviour at 1535 nm is also investigated, and the obtained saturation output power is larger than 10 dBm.