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@MASTERSTHESIS{Ravi:207668,
      author       = {Ravi, Koustuban},
      title        = {{T}heory of terahertz generation by optical rectification},
      school       = {Massachusetts Institute of Technology},
      type         = {MS},
      address      = {Cambridge, MA, USA},
      reportid     = {PUBDB-2015-01424},
      year         = {2014},
      note         = {Copyright 2014, Massachusetts Institute of Technology. All
                      rights reserved.; Massachusetts Institute of Technology,
                      Masterarbeit, 2014},
      abstract     = {Intense pulses of light with wavelengths, approximately ten
                      times smaller than microwave sources and a hundred times
                      larger than optical/near infra-red sources may be
                      categorized as high-field Terahertz (THz) sources. By virtue
                      of their large electromagnetic field amplitudes and
                      relatively long wavelengths, they are uniquely amenable for
                      electron acceleration, coherent X-ray generation and
                      non-linear spectroscopy. Intra-pulse difference frequency
                      generation or optical rectification of ultrafast optical
                      pump pulses in non-linear crystals has emerged as the most
                      efficient approach for high-field THz generation. Earlier
                      theoretical treatment of these systems had predicted
                      conversion efficiencies as high as $10\%,$ which opened up
                      the possibility of generating THz pulses with energies on
                      the order of 10 milli-joules. However, experimental
                      demonstrations have achieved conversion efficiencies of only
                      a few-percent which motivates a re-examination of the
                      existing theory. In this thesis, we present a formulation
                      which for the first time simultaneously considers effects
                      of: (i) the spatio-temporal distortions of ultrafast pulses,
                      (ii) the non-linear coupled interaction of optical and THz
                      radiation in two spatial dimensions (2-D), (iii) self-phase
                      modulation and (iv) stimulated Raman scattering. The key
                      finding is that THz generation necessarily leads to
                      broadening of the optical pump spectrum, which ultimately
                      limits further generation of THz radiation. Due to this
                      self-limiting mechanism, it is shown that the predicted
                      conversion efficiencies reduce significantly in relation to
                      earlier predictions, which is in line with experimental
                      trends. Guidelines to optimize conversion efficiency and
                      their ramifications on other THz properties are discussed.
                      The predictions and analyses are supported by experiments.
                      These findings direct future work towards careful
                      engineering of such systems to achieve optimal THz pulse
                      properties and the conception of approaches to circumvent
                      the aforementioned self-limiting effects.},
      keywords     = {Unveröffentlichte Hochschulschrift (GND)},
      cin          = {FS-CFEL-2},
      cid          = {I:(DE-H253)FS-CFEL-2-20120731},
      pnm          = {Experiments at CFEL (POF2-544)},
      pid          = {G:(DE-H253)POF2-CFEL-Exp.-20130405},
      experiment   = {EXP:(DE-H253)CFEL-Exp-20150101},
      typ          = {PUB:(DE-HGF)19},
      url          = {https://bib-pubdb1.desy.de/record/207668},
}