Amplifier/filter combination

摘要

An amplifier/filter combination including a fibre amplifier (4) and a fibre reflection/transmission filter (5) coupled to said amplifer. The fibre amplifier amplifies an input signal (1) in response to pump light (2) received from a laser. Preferably the fibre filter (5) is a chirped Bragg fibre filter which is arranged to filter out the unabsorbed portion of the pump light from the output amplified signal and which reflects the unabsorbed portion (7) of the pump light back to the amplifier (4) for re-absorption therein. The amplified signal (6) is transmitted by the filter (5) to a receiver.