We study the effect of strong single scattering on the $C_0$ correlation of intensity fluctuations in a disordered ensemble of discrete scatterers. Diagrammatic calculations of the $C_0$ contribution to the spatial correlation function are carried out for both scalar and electromagnetic waves beyond the standard Born approximation. For a system of Mie particles, the dependence of $C_0$ on the size and refractive index of the scatterers is examined. It is found that for highly refracting particles, the $C_0$ correlation acquires a pronounced resonant character. Close to the resonances, due to correlations between more than two wave fields, the magnitude of $C_0$ grows drastically, greatly exceeding the value for Born scatterers.

• Received 17 May 2021
• Accepted 30 July 2021

DOI:https://doi.org/10.1103/PhysRevA.104.023517