Coherent multiple light scattering in Faraday active materials

Wave propagation in multiple scattering media shows various kinds of coherent phenomena such as coherent backscattering [1, 2] or Anderson localization [3], both of which are intimately connected to the concept of reciprocity. Manipulating reciprocity in such media is a powerful tool to study these phenomena in experiments [4]. Here we discuss the manipulation of reciprocity in reflection and transmission geometry for the case of light propagation in magneto-optical media. We show new experiments on coherent backscattering and speckle correlations in strongly scattering samples containing Faraday active materials (CeF3) with transport mean free path in the μm range, at low temperatures (T < 10 K) and high fields (B = 18 T). Under such conditions we observe the effect of a Faraday rotation saturation in multiple scattering measurements.publishe

Un exemple de propagation non-linéaire dans les fibres optiques : la rétro-diffusion Brillouin stimulée

On passe en revue les principaux comportements possibles lors de la propagation d'impulsions optiques en présence de diffusion Brillouin stimulée (DBS), y compris une situation expérimentale de propagation supraluminique.This paper reviews the main behaviors of optical pulses in presence of stimulated Brillouin scattering (DBS), including experimental evidence of superluminous propagation

MAGNETO-OPTICAL AND MAGNETIC PROPERTIES NEODYNIUM SUBSTITUTED GARNETS

La rotation Faraday (ϕF) et l'aimantation (M) de ferrites grenats substitués NdxY3-xFe5O12 sont étudiés et ce pour x variant de 0,46 à 1,06. ϕF est mesuré à 1.15 micron entre 77 et 300 K en champ de 20 kOe parallèle à la direction [111]. ϕF est fortement influencé par la présence de l'ion Nd3+. Les mesures magnétiques effectuées entre 4,2 et 300 K en champ de 50 kOe montrent que l'ion Nd3+ a un moment bien supérieur à celui obtenu dans les échantillons polycristallins. Pour interpréter la forte rotation Faraday, un modèle de paire Nd3+, Fe3+ (octa) est proposé.The magnetization (M) and 1.15 µm wavelength Faraday rotation (ϕF) of NdxY3-xFe5O12 (x varies from 0.46 to 1.06) single crystals have been measured. On one hand ϕF has been studied from 77 to 300 K in a field up to 20 kOe applied along the [111] direction, it is strongly enhanced by the Nd3+ presence. The magnetic study reveals a magnetic moment per Nd3+ ion higher than the value previously observed in polycrystalline samples. From the ϕF dispersion study, a pair transition including Nd3+ and Fe3+ (octa) ions is proposed to explain the high specific Faraday rotation of these substituted garnets