Low pump power photonic crystal fibre amplifiers

Designs of low pump power optical amplifiers, based on photonic crystal fibres are presented. The potential of these fibre amplifiers is investigated, and it is demonstrated that such amplifiers may deliver gains of more than 15 dB at 1550 nm with less than 1 mW of optical pump power. We focus on the design of erbium-doped photonic crystal fibre amplifiers operated at very low pump powers. We achieve this by using PCFs with large air holes and thereby large index contrasts. With such high index contrast fibres, we may obtain very small mode field diameters.