Physical Review
Measurement of Fourth-Order Coherence Functions
Mark J. Beran, John B. DeVelis, George B. Parrent
Abstract
In this paper we outline a method which allows one, in principle, to measure $〈{E}_{i}({\mathrm{x}}_{1}, t){E}_{j}({\mathrm{x}}_{2}, t){{E}_{k}}^{*}({\mathrm{x}}_{3}, t)\ifmmode\times\else\texttimes\fi{}{{E}_{l}}^{*}({\mathrm{x}}_{4}, t)〉$ (in general, ${\mathbf{x}}_{1}$\ensuremath{\ne}${\mathbf{x}}_{2}$\ensuremath{\ne}${\mathbf{x}}_{3}$\ensuremath{\ne}${\mathbf{x}}_{4}$), for stationary quasimonochromatic light propagating principally in the forward direction. The procedure makes use of the properties of nonlinear dielectrics in a sequence of interference experiments. No correlation of photoelectron currents is used, and as a special case the contracted moment $〈{|{E}_{i}({\mathrm{x}}_{1}, t)|}^{2}{|{E}_{j}({\mathrm{x}}_{2}, t)|}^{2}〉$ measured by Hanbury Brown and Twiss could be obtained in this manner. It is shown that it should be possible to measure the full fourth-order coherence function in the laboratory for laser light, using presently obtainable intensity levels.