Review of rare earth doped fibre lasers and amplifiers

Recent developments in rare earth doped fibre lasers and amplifiers are reviewed. Fibre lasers have been made to operate at a variety of wavelengths, including the important 1.3 μm, 1.55 μm and the 2 to 3 μm regions in the infrared. The spectra of the rare earth ions and the nature of the host materials that make such lasing wavelengths possible are discussed. Methods for the manufacture of rare earth doped fibres are reviewed. A number of cavity designs for fibre lasers have been demonstrated, which have facilitated low loss coupling to transmission fibres, single longitudinal mode operation, Q-switching and mode locking. The performance of these systems is described. The operation of rare earth doped fibre amplifiers is also discussed