% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@PHDTHESIS{Ritzkowsky:597811,
      author       = {Ritzkowsky, Felix},
      othercontributors = {Kärtner, Franz and Küpper, Jochen},
      title        = {{E}lectronics at {O}ptical {F}requencies},
      school       = {Universität Hamburg},
      type         = {Dissertation},
      address      = {Hamburg},
      publisher    = {Verlag Deutsches-Elektronen Synchrotron},
      reportid     = {PUBDB-2023-06679, DESY-THESIS-2023-018},
      series       = {DESY-THESIS},
      pages        = {146},
      year         = {2023},
      note         = {Dissertation, Universität Hamburg, 2023},
      abstract     = {With the advent of ultrafast optics and controllable
                      waveforms consisting of only a few oscillations of the
                      electric field, the idea of controlling electrons at the
                      frequency of light was born. This established the potential
                      of using a controlled optical waveform to switch electronic
                      circuit elements at the frequency of an optical wave,
                      typically on the order of 0.1 to 1 petahertz(1015 Hz). This
                      exceeds the frequency of the fastest electronic devices by
                      two to three orders of magnitude and the clock rates of
                      modern computers by up to six orders of magnitude. Tothis
                      end, many pioneering experiments have shown that optical
                      waveforms can be used to drive attosecond electron currents
                      at metal-vacuum interfaces, in dielectric large bandgap
                      materials or in air. This thesis shows how integrated
                      metallic nanoantennas are utilized to enhance the electric
                      field of optical few-cycle pulses in nanometer-sized
                      hotspots, generating sub-cycle field emission with only
                      picojoule-level pulse energies. Exploiting the
                      attosecond-fast currents on the nanoscale, petahertz
                      bandwidth field sampling with 5 femtojoule sensitivity is
                      experimentally demonstrated [20]. The influence of antenna
                      symmetry and device design on the sampling frequency
                      response is investigated theoretically to guide application
                      specific design strategies [21]. To further test the
                      integrated nanoantenna platform, we have developed a
                      passively CEP-stable sub-2-cycle laser source that produces
                      16 fs duration pulsesat a central wavelength of 2.7 µm with
                      > 84 nJ energy at a repetition rate of 50 kHz. The system is
                      based on adiabatic difference generation [22], and
                      significantly simplifies previous implementations by relying
                      solely on material-based compression. Furthermore, the CEP
                      stability of adiabatic difference generation is measured for
                      the first time and shows excellent passive stability of 190
                      mrad rms. We show that by using the newly developed
                      mid-infrared sub-2-cycle source, the CEP dependent yield of
                      a single nanoantenna is significantly improved by a factor
                      of 30 from a previous 0.1 electrons per laser shot to > 3
                      electrons [10, 23]. Thanks to this significant improvement,
                      and by illuminating up to 1000 antennas, we produce fully
                      carrier-envelope phase (CEP) dependent currents of up to
                      3000 electrons per shot, improving previous results by three
                      orders of magnitude [23]. The results of this work will open
                      many interesting avenues for the exploration of optical
                      frequency electronics based on integrated nanoantennas, such
                      as ultra-broadband time spectroscopy in the infrared
                      continuously covering the terahertz to visible spectrum, or
                      petahertz bandwidth logic circuits.},
      cin          = {FS-CFEL-2},
      cid          = {I:(DE-H253)FS-CFEL-2-20120731},
      pnm          = {631 - Matter – Dynamics, Mechanisms and Control
                      (POF4-631) / DFG project 453615464 - Dielektrischer
                      Laserbeschleuniger im mittleren Infrarotbereich (453615464)
                      / DFG project 390715994 - EXC 2056: CUI: Advanced Imaging of
                      Matter (390715994)},
      pid          = {G:(DE-HGF)POF4-631 / G:(GEPRIS)453615464 /
                      G:(GEPRIS)390715994},
      experiment   = {EXP:(DE-H253)AXSIS-20200101},
      typ          = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
      doi          = {10.3204/PUBDB-2023-06679},
      url          = {https://bib-pubdb1.desy.de/record/597811},
}