Researchers have found new methods for optimising glass in order to increase the lifetime of fibre lasers. The trend is to produce fibre lasers with higher output powers, which places great demands on the optical fibre. This has been shown at Mid Sweden University in Sweden.
The interest in fibre lasers has increased dramatically in the last decade. The main driving force is coming from the industry, where these lasers are used for different kinds of materials processing such as cutting, drilling, and welding. The fibre laser offers many advantages compared with conventional lasers in terms of better beam quality, lower prices, and a more compact design. However, it turns out that the glass material in the optical fibre looses its transparency with time, a phenomenon called 'photodarkening.' This effect considerably shortens the operational lifetime of the fibre laser.
'This is primarily a concern at high output levels associated with applications using a pulsed laser configuration,' says Magnus Engholm, a doctoral candidate in fibre optics.
One example of such applications is marking, where part of the surface material has to be burnt off from the object to be marked.
Fortunately the glass material can be optimised to extend the lifetime of these lasers. By choosing a proper composition and optimising the synthesis conditions, scientists can now attain higher output powers and longer lifetimes. This will also open up for new areas of industrial application.
This research has been carried out collaboratively by Mid Sweden University and Acreo FiberLab.