title: Observation of antinormally ordered Hanbury Brown-Twiss correlations.
abstract: We have measured antinormally ordered Hanbury Brown-Twiss correlations for coherent states of the electromagnetic field by using a stimulated parametric down-conversion process. Photons were detected by stimulated emission, rather than by absorption, so that the detection responded not only to actual photons but also to zero-point fluctuations via spontaneous emission. The observed correlations were distinct from normally ordered ones as they showed excess positive correlations, i.e., photon bunching effects, which arose from the thermal nature of zero-point fluctuations.
authors.affiliation: Department of Material Science and Engineering, Tokyo Institute of Technology, Yokohama 226-0026, Japan. usami@frl.cl.nec.co.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Usami
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nambu
authors.forename: Bao-Sen
authors.initials: BS
authors.lastname: Shi
authors.forename: Akihisa
authors.initials: A
authors.lastname: Tomita
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nakamura