Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

The scattering properties of an anisotropic solid for polarized light allow the observation and the measurement of linear, circular and elliptic birefringence. A general analysis of the phenomenon for any kind of birefringence and any state of polarization of the incident light vibration is given. Scattering by particles with size a [formula omitted] λ (Rayleigh limit) or a ≈ λ is considered. It follows from the theory that the scattering-center distribution is equivalent to a quasi-continuous array of analyzers providing a simultaneous analyzation of the transmitted beam along its whole path in the (in general elliptically) biréfringent medium. A new technique based on surface scattering is described. It allows visual observations to be made on very perfect (hence weakly scattering) crystals with low-power light sources and without being forced to achieve complete darkness in the surroundings of the sample. The method of surface scattering is especially adequate for precision measurements; it is thoroughly tested with the elliptic birefringence of quartz. Both methods of surface and bulk scattering are applied to various kinds of birefringence in single crystals of Eu2SiO4 and EuTe.