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@PHDTHESIS{Braun:643144,
      author       = {Braun, Cora},
      othercontributors = {Maier, Andreas and Kärtner, Franz},
      title        = {{S}tretcher and {A}mplifier design for the {LPA} {D}rive
                      {L}asers {ANGUS} and {KALDERA}},
      school       = {Universität Hamburg},
      type         = {Dissertation},
      address      = {Hamburg},
      publisher    = {Verlag Deutsches Elektronen-Synchrotron DESY},
      reportid     = {PUBDB-2026-00042, DESY-THESIS-2025-023},
      series       = {DESY-THESIS},
      pages        = {148},
      year         = {2026},
      note         = {Dissertation, Universität Hamburg, 2025},
      abstract     = {Laser-plasma accelerators (LPAs) are a promising technology
                      to build compact andcost-efficient accelerators for a
                      variety of applications. To realize this promise,
                      thereliability and long-term stability of the accelerated
                      electrons have to be improved.Much of this improvement
                      relates to the stability of the drive laser. Apart
                      fromimproving passive stability, increasing the repetition
                      rate of the laser from a few Hzto >100 Hz, enables the use
                      of active stabilizations, that can account for many
                      lowerfrequency contributions from e.g. mechanical vibrations
                      and air-fluctuations. Theoverarching goal of the thesis is
                      to develop setups for the Ti:Sa CPA TW-class lasersystems
                      ANGUS and KALDERA, that allow for a stable laser performance
                      andacceleration of high-quality electrons.To improve the
                      long-term stability of the ANGUS laser, a new, more stable
                      front-end,based on optical-parametric chirped-pulse
                      amplification (OPCPA) was built. Thisthesis reports on the
                      design, alignment and characterization of the stretcher,
                      that wasrequired to integrate the OPCPA front-end into the
                      laser system. The design goalwas to achieve a stable and
                      tunable stretcher and to minimize the angular chirp ofthe
                      output beam by alignment with a three-color-laser. The
                      characterization of thestretcher and its implementation into
                      the laser system, which led to the compressionof pulses to
                      31 fs with sub-percent pulse duration stability will be
                      presented.With KALDERA a >100Hz repetition rate LPA drive
                      laser is currently being developedon DESY campus. To
                      withstand the >100W average power in the final
                      pulsecompressor, multi-layer dielectric (MLD) gratings need
                      to be used. This thesis reportson the development, setup and
                      characterization of a two-transmission grating,
                      two-passOeffner stretcher, that matches such a MLD
                      compressor. Using this stretcher, compressionto sub-30 fs
                      pulse lengths at Ti:Sa wavelength in an out-of-plane
                      compressorwith MLD gratings could be demonstrated for the
                      first time. The characterization ofthe output pulses showed
                      the viability of the stretcher and compressor concept for
                      theKALDERA laser and other future high-average power, TW, fs
                      laser systems.To efficiently seed the final amplifiers, a
                      Booster amplifier is required for the KALDERAlaser. The
                      designed three-pass Ti:Sa amplifier provides 0.5-1mJ output
                      energy andsub-percent energy stability. The stretcher and
                      the Booster amplifier successfully seedthe KALDERA
                      multi-pass amplifiers to saturation, enabling $sub-0.5\%$
                      energy stabilityin the final amplifier stage.},
      cin          = {MPL},
      cid          = {I:(DE-H253)MPL-20120731},
      pnm          = {621 - Accelerator Research and Development (POF4-621)},
      pid          = {G:(DE-HGF)POF4-621},
      experiment   = {EXP:(DE-H253)LUX-Beamline-20221201},
      typ          = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
      urn          = {urn:nbn:de:gbv:18-ediss-133887},
      doi          = {10.3204/PUBDB-2026-00042},
      url          = {https://bib-pubdb1.desy.de/record/643144},
}