@article{MenzelHeuerPuhlmannetal.2013,
  author    = {Menzel, Ralf and Heuer, Axel and Puhlmann, Dirk and Dechoum, K. and Hillery, M. and Spaehn, M. J. A. and Schleich, W. P.},
  title     = {A two-photon double-slit experiment},
  series = {Journal of modern optics},
  volume    = {60},
  journal   = {Journal of modern optics},
  number    = {1},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {0950-0340},
  doi       = {10.1080/09500340.2012.746400},
  pages     = {86 -- 94},
  year      = {2013},
  abstract  = {We employ a photon pair created by spontaneous parametric down conversion (SPDC) where the pump laser is in the TEM01 mode to perform a Young's double-slit experiment. The signal photon illuminates the two slits and displays interference fringes in the far-field while the idler photon measured in the near-field in coincidence with the signal photon provides us with which-slit' information. We explain the results of these experiments with the help of an analytical expression for the second-order correlation function derived from an elementary model of SPDC. Our experiment emphasizes the crucial role of the mode function in the quantum theory of radiation.},
  language  = {en}
}
@article{HeuerSagahtiJechowetal.2012,
  author    = {Heuer, Axel and Sagahti, A. and Jechow, Andreas and Skoczowsky, D. and Menzel, Ralf},
  title     = {Multi-wavelength, high spatial brightness operation of a phase-locked stripe-array diode laser},
  series = {Laser physics},
  volume    = {22},
  journal   = {Laser physics},
  number    = {1},
  publisher = {Pleiades Publ.},
  address   = {New York},
  issn      = {1054-660X},
  doi       = {10.1134/S1054660X12010057},
  pages     = {160 -- 164},
  year      = {2012},
  abstract  = {Stable continuous wave multi-wavelength operation of a stripe-array diode laser with an externalcavity spectral beam combining geometry is presented. In this setup each emitter of the stripe-array is forced to operate at a different wavelength, which leads to a decoupling between the usually phase-locked emitters. With a reflective diffraction grating with a period of 300 lines per mm, 33 equidistant laser lines around a center wavelength of 978 nm were realized, spanning a spectral range of 26 nm. With this novel approach near-diffraction limited emission with a beam quality of M (2) < 1.2 and an output power of 450 mW was achieved. This laser light source can be used for applications requiring low temporal but high spatial coherence.},
  language  = {en}
}
@article{HeuerMenzelMilonni2015,
  author    = {Heuer, A. and Menzel, R. and Milonni, P. W.},
  title     = {Induced Coherence, Vacuum Fields, and Complementarity in Biphoton Generation},
  series = {Physical review letters},
  volume    = {114},
  journal   = {Physical review letters},
  number    = {5},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {0031-9007},
  doi       = {10.1103/PhysRevLett.114.053601},
  pages     = {5},
  year      = {2015},
  abstract  = {It is well established that spontaneous parametric down-conversion with induced coherence across two coupled interferometers results in high-visibility single-photon interference. We describe experiments in which additional photon channels are introduced such that "which-path" information is made possible and the fringe visibility in single-photon interference is reduced in accordance with basic notions of complementarity. However, these additional pathways result in nearly perfect visibility when photons are counted in coincidence. A simplified theoretical model accounts for these observations and attributes them directly to the vacuum fields at the different crystals.},
  language  = {en}
}