A low-noise erbium-doped fibre amplifier operating at 1.54 μm has been demonstrated, achieving a maximum gain of 28 dB over a 3 m long fibre. The amplifier has a spectral bandwidth of over 300 GHz around 1.536 μm and a measured sensitivity of -42 dBm at 140 Mbit/s. The amplifier uses an optically pumped rare-earth-doped fibre, offering a third approach to optical amplification, which eliminates the need for electronic signal conversion and provides a projected bandwidth of over 100 GHz. The amplifier was tested with a 3 m long erbium-doped fibre (NA = 0.2, λcutoff = 1.4 μm, dopant concentration ≈ 10¹⁹ cm⁻³) reverse-pumped with light from a CW DCM-dye laser. The signal was provided by a 1.54 μm GaInAsP DCPBH laser, with the wavelength tunable from 1.532 to 1.540 μm. The amplifier's gain was measured against pump power and wavelength, showing a threshold power of over 10 mW and a gain of 20 dB for approximately 20 mW absorbed in the fibre. The amplifier's gain saturates at a high degree of inversion in the three-level Er³+ system. The amplifier's power transfer characteristic shows that it can handle considerably more power than semiconductor laser amplifiers, making it suitable for multichannel communication systems. The amplifier's spectral dependence is similar to the fluorescence spectrum, with the highest gains available in a 300 GHz bandwidth centred on 1.536 μm. The amplifier's noise performance was measured to be 200 pA/√Hz, corresponding to a sensitivity of -42 dBm at 140 Mbit/s for a 10⁻⁹ bit error rate. The amplifier's excellent power handling characteristics and potential for high sensitivity make it suitable for both long-distance telecommunications and local networks. The amplifier is expected to make an important impact in optical communication systems.A low-noise erbium-doped fibre amplifier operating at 1.54 μm has been demonstrated, achieving a maximum gain of 28 dB over a 3 m long fibre. The amplifier has a spectral bandwidth of over 300 GHz around 1.536 μm and a measured sensitivity of -42 dBm at 140 Mbit/s. The amplifier uses an optically pumped rare-earth-doped fibre, offering a third approach to optical amplification, which eliminates the need for electronic signal conversion and provides a projected bandwidth of over 100 GHz. The amplifier was tested with a 3 m long erbium-doped fibre (NA = 0.2, λcutoff = 1.4 μm, dopant concentration ≈ 10¹⁹ cm⁻³) reverse-pumped with light from a CW DCM-dye laser. The signal was provided by a 1.54 μm GaInAsP DCPBH laser, with the wavelength tunable from 1.532 to 1.540 μm. The amplifier's gain was measured against pump power and wavelength, showing a threshold power of over 10 mW and a gain of 20 dB for approximately 20 mW absorbed in the fibre. The amplifier's gain saturates at a high degree of inversion in the three-level Er³+ system. The amplifier's power transfer characteristic shows that it can handle considerably more power than semiconductor laser amplifiers, making it suitable for multichannel communication systems. The amplifier's spectral dependence is similar to the fluorescence spectrum, with the highest gains available in a 300 GHz bandwidth centred on 1.536 μm. The amplifier's noise performance was measured to be 200 pA/√Hz, corresponding to a sensitivity of -42 dBm at 140 Mbit/s for a 10⁻⁹ bit error rate. The amplifier's excellent power handling characteristics and potential for high sensitivity make it suitable for both long-distance telecommunications and local networks. The amplifier is expected to make an important impact in optical communication systems.