Polychromatic propagation-invariant fields (localized waves) with variable spectral coherence properties are considered. A bridge is provided between coherent propagation-invariant pulses, including Bessel pulses, X-waves and focus wave modes, and stationary polychromatic propagation-invariant fields using a difference-frequency spectral-correlation model. In the space-time domain, this assumption leads to a representation of a partially coherent field as a continuum of spectrally fully coherent, mutually independent pulses originating at different instants of time. The influence of partial spectral coherence on temporal coherence and pulse shape as well as intensity distribution and transverse spatial coherence is illustrated by considering fields with propagation-invariant Bessel-mode monochromatic components.

• Received 25 June 2009

DOI:https://doi.org/10.1103/PhysRevA.80.053804