Research Article

Propagation of partially coherent fields radiated by sources with univariable cross-spectral density

¹ DIIEM, Università Roma Tre, via V. Volterra 62, Rome 00146, Italy
² Departamento de Óptica, Fac. CC. Físicas, U.C.M., Ciudad Universitaria s/n, 28040 Madrid, Spain
³ Universidad Politécnica de Madrid, ETSIS de Telecomunicación, Campus Sur, 28031 Madrid, Spain
⁴ Department of Physics, University of Miami, 1320 Campo Sano Drive, Coral Gables, FL, 33146, USA

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 18 December 2025
Accepted: 4 February 2026

Abstract

A new class of partially coherent light sources, the sources with uni-variable cross-spectral density (CSD), has been recently introduced. Their CSD is obtained starting from any function of a single complex argument having non-negative Taylor coefficients. This allows the conception of a virtually infinite number of physically realizable partially coherent sources. Here, the main characteristics of sources of this class are investigated through examples, with particular reference to the irradiance and coherence properties across the source plane and upon propagation, both in the near and in the far field. Furthermore, since the coherent modes of such sources present optical vortices, parameters quantifying the vortex structure of the field across the source plane are also evaluated for the presented cases.