Faculté des Sciences, 40, avenue du Recteur-Pineau, 86022 Poitiers, France (Reçu le 22 novembre 1972) Résumé. 2014 Nous avons préparé par une méthode de Piper et Polich modifiée des mono cristaux cubiques de ZnSe de bonne qualité optique et qui présentent un effet électro-optique linéaire. L'étude expérimentale de cet effet a permis de constater que le coefficient électro-optique r41 du ZnSe varie avec la longueur d'onde (0,5 03BC 03BB 0,6 03BC), mais que par contre l'intensité de la modulation optique semble indépendante de 03BB et ne dépend que du champ électrique appliqué au cristal. Abstract. 2014 Cubic ZnSe crystals were grown by a modified Piper and Polich method. These crystals of good optical quality present a linear electro-optic effect. An experimental study of this effect shows that the electro-optic coefficient r41 for ZnSe varies with the wavelength (0.5 03BC 03BB 0.6 03BC), but the intensity of the optical modulation seems independent of 03BB and only depends on the electric field applied to the crystal.
ZnSe single crystals grown in vapour phase technique with sphalerite structure are cut according to faces (110), (110), (001) in order to study the coefficient γ41 of the electrooptic tensor. These samples exhibit, without any electric field applied, a parasitic birefringence linked to the plane crystal defects. This ZnSe is biaxial and presents a great dispersion of index as well as a variation of the position of the optic axes between the absorption threshold and 6000 Å, but the axis [110] remains always a principal axis for the dielectric tensor.
Nous avons préparé par pulvérisation cathodique réactive des couches minces de SnO2, conductrices et transparentes. Ces couches très adhérentes présentent un coefficient de transmission moyen de 90 % dans le spectre visible, et ont une résistance constante entre — 180 °C et + 200 °C
An anomalous but weak photovoltaic effect has been observed in cubic crystals of zinc selenide in the spectral range of the absorption tail. Parallelepiped samples exhibit twinned and birefringent strips, and a photovoltage of about 100 mV with reversal of sign appears when the electrodes are parallel to the twinning planes. A study of the optical absorption tail shows that the absorption coefficient is different from a twinned area and an untwinned area. It is attempted to explained qualitatively the experimental results with a model derived from that of Cutter and Woods (1975) when the wavelength is greater than the optical absorption threshold.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.