2Technische Universität Dresden, Zellescher Weg 19, 01069 Dresden, Germany
We report on the energetic and beam quality performance of the second to the last main amplifier section HEPA I of the PEnELOPE laser project. A polarization coupled double-12-pass scheme to verify the full amplification capacity of the last two amplifiers HEPA I and II was used. The small signal gain for a narrow-band continuous wave laser was 900 and 527 for a broadband nanosecond pulse, demonstrating 12.6 J of output pulse energy. Those pulses, being spectrally wide enough to support equivalent 150 fs long ultrashort pulses, are shown with an excellent spatial beam quality. A first active correction of the wavefront using a deformable mirror resulted in a Strehl ratio of 76% in the single-12-pass configuration for HEPA I.
D. Albach, M. Loeser, M. Siebold, U. Schramm. Performance demonstration of the PEnELOPE main amplifier HEPA I using broadband nanosecond pulses[J]. High Power Laser Science and Engineering, 2019, 7(1): 010000e1