Abstract

High power fibre laser technology has come of age over the past five years or so, due primarily to developments in fibre design and fabrication and semiconductor pump lasers. Fibre is now emerging as the technology of choice for a wide range of laser applications. Nowhere has the progress been more striking than in terms of the maximum continuous wave output power achievable from a single-mode fibre laser. Up until the start of 2001 the maximum reported output power from such a laser was ~110W. However, since then the reported power levels have risen rapidly and steadily such that by late 2006 values as high as 2.5kW were achieved with great prospects for further extension to the l0kW regime. Far higher power levels than this should be achievable in due course using beam combination technology. Fibre lasers are thus consequently now strong competitors to KW-class ‘bulk’ and thin-disk solid state lasers (for example, Nd:YAG and Yb:YAG) and CO₂ lasers for a wide range of industrial applications including materials processing, aerospace and defense. Relative to these competing technologies fibre lasers benefit from the advantages of compactness, efficiency, beam quality and arguably most importantly ready thermal management due to the large surface-area to volume ratio of the fibre geometry. The fibre laser is thus seen to have the potential to revolutionize both the range of uses and economics of high power laser systems.

© 2007 IEEE