Scattering of higher-order Gaussian beams by an infinite cylinder

The theory of scattering of higher-order Gaussian beams by an infinite cylinder with arbitrary location and arbitrary orientation is presented. An ingredient of the theory is the use of distributions. Gaussian beams are described by using the so-called standard description, the localized approximation and the modified localized approximation in a unified framework. Computations are explicitly carried out up to terms which are , in which s is the beam confinement parameter. L'article presente la theorie de la diffusion de faisceaux gaussiens d'ordre eleve par un cylindre infini, avec orientation et position arbitraires dans le faisceau. Cette theorie utilise la theorie mathematique des distributions. Les faisceaux gaussiens sont decrits de maniere dite standard, ou par des approximations dites localisees.