1999/07/01 by Pierre-Anthony Lemieux, D. J. Durian · 6 citations
Chemistry · Physics and Astronomy · #Random lasers and scattering media #Spectroscopy and Chemometric Analyses #Spectroscopy and Quantum Chemical Studies
paper · doi:10.1364/josaa.16.001651
openalex publication_date 1999/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Dynamic light-scattering techniques provide noninvasive probes of diverse media, such as colloidal suspensions, granular materials, or foams. In homodyne photon correlation spectroscopy, the dynamical properties of the medium are extracted from the intensity autocorrelation g(2)(τ) of the scattered light by means of the Siegert relation g(2)(τ)=1+|〈E(0)E*(τ)〉|2/〈EE*〉2. This approach is unfortunately limited to systems where the electric field is a Gaussian random variable and thus breaks down when the scattering sites are few or correlated. We propose to extend the traditional analysis by introducing intensity correlation functions g(n) of higher order, which allow us both to detect non-Gaussian scattering processes and to extract information not available in g(2) alone. The g(n) are experimentally measured by a combination of a commercial correlator and a custom digital delay line. Experimental results for g(3) and g(4) are presented for both Gaussian and non-Gaussian light-scattering processes and compared with theoretical predictions.