Patent ID: 8270070

Claim:
An amplifying optical device to provide optical amplification, comprising: at least one pump adapted to supply pump radiation; at least one pump optical fibre section; at least one amplifying optical fibre section comprising a core and a cladding; and wherein: the pump optical fibre section and the amplifying optical fibre section are made substantially from glass; a portion of the pump optical fibre section is separated from the amplifying optical fibre section, and is connected to the pump; the pump optical fibre section and the amplifying optical fibre section are coated with a common coating and are in optical contact with each other along at least a portion of their length; the common coating has a refractive index which is lower than a refractive index of a cladding material of the pump optical fibre section; the optical amplification is provided substantially by the said portion of the length in which the pump optical fibre section and the amplifying optical fibre section are coated and are in optical contact with each other, and the pump optical fibre section and the amplifying optical fibre section are in the form of an optical fibre cable.