Recent advances in ultrafast semiconductor disk lasers

As small, ultrashort-pulse lasers with high peak powers, semiconductor thin-disk lasers hold promise for spectroscopy, metrology and imaging. Bauke Tilma and co-workers from ETH Zurich review recent progress in developing such lasers for these applications. They report how the latest designs of external-cavity disk lasers that are passively mode locked using a saturable absorber now offer repetition rates of up to 100 gigahertz, pulse durations of shorter than 200 femtoseconds and peak powers in the kilowatt range. The compact design, excellent noise performance and customizable emission wavelength of such sources make them highly attractive for a variety of applications. Future research into the materials providing the optical gain and saturable absorption in such lasers is likely to further improve their efficiency, reliability and thermal stability.