Operation of the L3-HAPLS laser system (ELI Beamlines Research Centre) at 0.5 PW level was demons­trated through compression of the full energy output pulses currently generated by the laser chain, in the Petawatt vacuum compressor. The L3-HAPLS is a system designed for sustained operation with repe­tition rate 10 Hz. In the demons­tration run, the L3-HAPLS pump laser was operated at 101 J energy, driving the high-power Ti:sapphire short-pulse amplifier and resulting in 17.7 J of pulse energy at the output of the chain, before entering the vacuum pulse compressor.

The energy of the generated output pulses was highly stable with only 0.4 % fluctuations. The long-term sustained performance of the laser at high-repe­tition rate was verified previously without the Petawatt vacuum compressor, demons­trating that the laser is stable during conti­nuous operation of longer than one hour. By accounting for reflec­tivity of the compressor gratings, compressed pulses with 13.3 J of energy were generated, with duration of 27.3 fs. This corresponds to peak power of about 490 TW, or 0.49 PW.  Together with a 3.3 Hz repetition rate and pulse duration of <30 fs, this is the highest laser peak power ever demons­trated.

“The L3-HAPLS laser team worked hard during the last year to overcome several operational challenges and to get ready for commissioning experimental campaigns planned for the second half of this year. Finishing these campaigns success­fully will be a key step towards opening the high power experi­mental stations to the user community,” says Josef Cupal, the leader of L3-HAPLS. The ramping of energy of the full system through the compressor to the 0.5 PW level was done gra­dually in about 30 steps. After the run, a thorough visual inspection of the diffrac­tion gratings and other optical components inside the compressor was made. No problems were found and the L3-HAPLS system is now ready to start sending the short-pulse high-power beam to the experi­mental halls.

The L3-HAPLS laser system represents a new genera­tion of diode-pumped, high-energy and high-peak-power laser systems. The laser will serve in many areas of basic and applied research. Its most signi­ficant appli­cations include compact laser particle accelerator for new medical methods and short-wave X-ray generation for high resolution spatial and temporal reso­lution micro­scopy for material and medical research. The initial experi­ments will be focused on plasma physics and ion acce­leration. L3-HAPLS was designed, developed and constructed by Lawrence Liver­more National Labora­tory and delivered to ELI Beamlines in June 2017. (Source: ELI)

Link: Laser L3 HAPLS – The High-Repetition-Rate Advanced Petawatt Laser System, ELI-Beamlines, Dolní Břežany, Czech Republic