New technology mirrors ultra-fast fibre lasers
Until recently high-power, ultra-fast radiation could only be achieved using cumbersome, solid state lasers that are both expensive and unreliable. Thanks to a new type of laser that is significantly smaller, less expensive and more reliable the market for high-energy pulsed optical systems is now growing. Nowadays short-pulse fibre lasers can offer size and cost savings of up to 10 times compared to equivalent bulk-laser systems. Physicists working under the auspices of the Uranus project have used optical fibre technology to produce more powerful ultra-short pulses at various wavelengths and increased stability. The consortium has taken ultra-fast fibre laser technology to its limits and commercially exploited the new systems that it has developed. Semiconductor saturable absorber mirrors (SESAMs) play a vital role in generating ultashort-pulses using fibre lasers. Researchers identified the principal mechanism for shaping ultra-short pulses in fibre lasers and set the SESAMS to operate at 1550, 1060 and 980 nanometres (nm) respectively. A nanometre is one billionth of a metre. Advanced fibre amplifiers were used to increase power levels and the final systems used to produce broadband radiation in photonic crystal fibres. This approach was a significant step towards the generation of ultra-fast fibre oscillators and the results have exceeded expectations with regard to average power, spectral density and emission bandwidth. The work of the Uranus project has helped to put Europe at the forefront of ultra-fast fibre laser research. This will give the EU an economic edge by enabling it to develop new cutting-edge technologies.