Femtosecond laser reaches kilowatt range

An amplification concept developed for femtosecond lasers has enabled researchers to achieve mean power in the kilowatt range for the first time.

The scientists, from Fraunhofer Institute for Laser Technology, have taken a step that could expand the laser’s use into industrial production, resulting in greater throughput, lower maintenance costs and easier usability.

Resonator of the Yb:YAG Innoslab femtosecond amplifier. Courtesy of Fraunhofer Institute for Laser Technology.

The laser’s short pulses enable ultraprecise materials processing and greater precision during ablation. Its amplifier design is based on Fraunhofer’s Innoslab technology, a development characterized by a simple, robust and compact construction. The researchers extended the amplifier design to enable ultrashort pulse amplification through the large bandwidth from an yttrium-doped YAG as the active medium. The oscillator-amplifier system also enables greater flexibility in pulse duration and repetition rate.

By cascading two Innoslab amplifiers, the chain generated a mean power of 1.1 kW at a peak pulse power of 80 MW and pulse duration of 600 fs.

With the new power output levels, femtosecond lasers can be used in fields where their throughput did not suffice in the past. Applications for the new beam source in the microsector include nozzle drilling, tool and solar cell engineering, and printing technology.