Abstract

Solid-state sources with high output power in the ‘eyesafe’ 2µm spectral region have applications in medicine and LIDAR, and also provide an ideal starting wavelength for nonlinear frequency conversion to the mid-infrared (3-5µm) spectral region. For many of these applications high efficiency and good beam quality are also required. This combination of operating characteristics is often difficult to achieve in conventional ‘bulk’ solid-state lasers due to thermal effects, which degrade beam quality and reduce overall efficiency. Double-clad fibre lasers offers an alternative means for scaling to high power [1],[2] with the advantage that thermal loading is distributed over a long length of fibre minimising the risk of damage, and the beam quality is determined by the waveguiding properties of the core, which can easily be tailored to produce a single-mode output.

© 2000 IEEE