Jena team sets ultrashort pulse power record

Laser technology set to feature at Extreme Light Infrastructure attosecond pulse facility in Hungary.

Fingers on the pulse: the Jena team's ultrafast laser system

Researchers in Germany say that their new laser source being developed for the Extreme Light Infrastructure (ELI) project in eastern Europe has set a world record for power output with a “few cycle” pulse duration.

The Jena-based team, comprising the Friedrich Schiller University, the nearby Fraunhofer Institute for Applied Optics and Precision Engineering (IOF), and local start-up company Active Fiber Systems, have built a system delivering 216 W average power from a train of 6 fs pulses.

1 mJ target

That compares with the previous best of 53 W from 8 fs pulses, and represents a significant step towards the targeted energy output of 1 mJ at a repetition rate of 100 kHz (equivalent to an average power of 100 W) needed for ELI, said to be "well beyond the current state-of-the-art".

Jens Limpert from the Jena team told optics.org that further progress towards that performance goal has already been made. Limpert and colleagues are now working to tweak the system before its scheduled shipment to ELI-ALPS in Szeged, Hungary, early next year.

Described in a recent Optics Letters journal paper, the system is based around a femtosecond fiber laser and features two non-linear compression stages. That pump source incorporates a fiber chirped-pulse amplification (FCPA) system with a coherent combination of up to eight main amplifier channels. For some of the first tests, the system was run at 1.27 MHz, delivering 660 W.

The two non-linear compression stages are based on noble-gas-filled capillaries. The first stage produced a 408 W output with a laser pulse length of about 30 fs (equivalent to 320