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Adam Ciarkowski

Publications and source records attributed to Adam Ciarkowski.

2 recordsLinked to original sources
arXiv2004

On Sommerfeld precursor in a Lorentz medium

A one-dimensional electromagnetic problem of Sommerfeld precursor evolution, resulting from a finite rise-time signal excitation in a dispersive Lorentz medium is considered. The effect of the initial signal rate of growth as well as of the medium dumping on the precursor shape and its magnitude is discussed. The analysis applied is based on an approach employing uniform asymptotic expansions. In addition, new approximate formulas are given for the location of the distant saddle points which affect local frequency and dumping of the precursor. The results obtained are illustrated numerically and compared with the results known from the literature.

physics.optics↗
arXiv2004

Dependence of the Brillouin precursor form on the initial signal rise time

Propagation of a Brillouin precursor in a Lorentz dispersive medium is considered. The precursor is excited by a sine modulated initial signal, with its envelope described by a hyperbolic tangent function. The purpose of the paper is to show how the rate of growth of the initial signal affects the form of the Brillouin precursor. Uniform asymptotic approach, pertinent to coalescing saddle points, is applied in the analysis. The results are illustrated with numerical examples.

physics.optics↗