Abstract: A fibre-optic module incorporating a semiconductor optical amplifier is compatible with a standard specification for a fibre-optic transceiver module, which is typically pluggable. The module comprises optical connectors capable of connection to first and second optical fibres and being in accordance with said standard specification and the input optical signal received from the first optical fibre is amplified by the semiconductor optical amplifier and supplied to the second optical connector for transmission along the second optical fibre. The module further comprises an electrical parallel connector having a physical configuration in accordance with said standard specification and a control circuit which receives control signals from the electrical parallel connector and to control the operation of the optical amplifier. Thus the module maybe connected to a standard electrical backplane alongside fibre-optic transceiver modules to augment the optical performance of the transceiver modules.