On the relation between Brillouin precursors in dispersive dielectric and viscoacoustic media

Dielectric media that exhibit dipole relaxation under an externally applied electromagnetic field are commonly described by the causal Debye model. Such media support the formation and propagation of the Brillouin precursor, which propagates with the phase velocity at dc and has an algebraic attenuation rate of its peak amplitude. This interesting property points to several applications of Brillouin precursors for communications and imaging through lossy dispersive media. This paper explores the possibility of pursuing such applications with acoustic pulses. To that end, a recently proposed causal model for viscoacoustic media, which can be interpreted as an extension of the Debye model, is employed to illuminate the analogies and discrepancies between acoustic and electromagnetic precursor fields.