@article{JechowSeefeldtKurzkeetal.2013,
  author    = {Jechow, Andreas and Seefeldt, Michael and Kurzke, Henning and Heuer, Axel and Menzel, Ralf},
  title     = {Enhanced two-photon excited fluorescence from imaging agents using true thermal light},
  series = {Nature photonics},
  volume    = {7},
  journal   = {Nature photonics},
  number    = {12},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {1749-4885},
  doi       = {10.1038/NPHOTON.2013.271},
  pages     = {973 -- 976},
  year      = {2013},
  abstract  = {Two-photon excited fluorescence (TPEF) is a standard technique in modern microscopy(1), but is still affected by photodamage to the probe. It has been proposed that TPEF can be enhanced using entangled photons(2,3), but this has proven challenging. Recently, it was shown that some features of entangled photons can be mimicked with thermal light, which finds application in ghost imaging(4), subwavelength lithography(5) and metrology(6). Here, we use true thermal light from a superluminescent diode to demonstrate TPEF that is enhanced compared to coherent light, using two common fluorophores and luminescent quantum dots, which suit applications in imaging and microscopy. We find that the TPEF rate is directly proportional to the measured(7) degree of second-order coherence, as predicted by theory. Our results show that photon bunching in thermal light can be exploited in two-photon microscopy, with the photon statistic providing a new degree of freedom.},
  language  = {en}
}
@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}
}