Électrodynamique des continus rigides de type différentiel

Abstract

In this paper, we consider a rigid polarizable continuum submitted to electromagnetic actions. Its constitutive equations depend on the polarization vector P and the time derivatives of this vector up to an arbitrary order n. A particular case of such a medium has been studied by Voigt [6] to explain selective absorption of electromagnetic waves and various electromagnetooptical effects. In order to study the propagation of plane waves in such continuum, we linearize the constitutive equations about an equilibrium state characterized by the static polarization vector 0P. Coleman's thermodynamical restrictions imply that these waves are absorbed but also that for n > 2 some causality requirements are generally not fulfilled. From Meixner's thermodynamical restrictions, it follows that the coefficients of the time derivatives of P greater than 2 must vanish, that the waves are absorbed, and that causality holds. With these restrictions, the continuum model considered exhibits various electrooptical effects such as optical resonance, Kerr effect, Pockels effect (in hemitropic media). When birefringence occurs, the two waves propagating in a direction have different resonance frequencies