Highly sensitive frequency metrology for optical anisotropy measurements

In this paper we present a novel apparatus aimed at measuring very small birefringences and anisotropies, based on frequency metrology and not on polarimetry as usual. In our experiment, a very high finesse resonant cavity is used to convert the phase difference into a resonance frequency difference, which can then be measured with very high accuracy. We describe the set-up and present the results of experimental tests which exhibited a sensitivity dn ~ 2 x 10?18, allowing for the measurement of long-predicted magneto-electro-optical effects in gases. Since the shotnoise limited sensitivity of our apparatus lies well below the state-of-the-art sensitivity, frequency metrology appears as a promising technique for small birefringence measurements.Comment: Accepted for publication in Review of Scientific Instrument

CtrlMouse et TouchCtrl : Dupliquer les Délimiteurs de Mode sur la Souris

National audienceModifier keys of the keyboard such as Ctrl or Cmd are used to delimit text entry and command selection (keyboard shortcuts). In this paper we study the impact of the position of these modifier keys on performance and muscular load by duplicating them on the mouse. We derive two interaction techniques: CtrlMouse duplicates the Ctrl and Shift keys by associating them to the mouse buttons under the thumb; TouchCtrl automatically triggers the Ctrl key when the hand lays on the mouse. Two laboratory experiments reveal that 1) as the task requires more pointing, participants use more these techniques, 2) the temporal cost of the use of modifier keys on command selection is 0.21s, which represents 11.9% of pointing time, and 3) selection time with CtrlMouse with one or two modifiers is similar. We also deployed these techniques to ecologically validate the results we obtained in the laboratory. Finally we present several application scenarios based on CtrlMouse and TouchCtrl.Les touches modifieur du clavier comme Ctrl ou Cmd sont utilisées pour délimiter l'entrée de texte de la sélection de commandes (raccourcis claviers). \ \ Dans cet article nous étudions l'impact de la localisation de ces délimiteurs sur la performance et la charge musculaire en les dupliquant sur la souris. À cet effet, nous dérivons deux techniques d'interaction : CtrlMouse duplique les touches Ctrl et Shift en les associant aux boutons de la souris sous le pouce; TouchCtrl déclenche automatiquement la touche Ctrl lorsque la main est posée sur la souris. Deux expériences en laboratoire révèlent 1) que ces techniques sont d'autant plus adoptées par les utilisateurs que la tâche demande du pointage, 2) le coût temporel des modifieurs sur la sélection de commandes est de 0,21s, ce qui correspond à 11,9% du temps de pointage et 3) le temps de sélection avec CtrlMouse avec un ou deux modifieurs est similaire. Nous avons également déployé ces techniques pour valider de manière écologique les résultats obtenus lors des évaluations en laboratoire. Enfin, nous présentons différents scénarios applicatifs élaborés à partir de CtrlMouse et TouchCtrl

Wavelet Menus: A Stacking Metaphor for Adapting Marking Menus to Mobile Devices

4 pagesInternational audienceExploration and navigation in multimedia data hierarchies (e.g., photos, music) are frequent tasks on mobile devices. However, visualization and interaction are impoverished due to the limited size of the screen and the lack of precise input devices. As a result, menus on mobile devices do not provide efficient navigation as compared to many innovative menu techniques proposed for Desktop platforms. In this paper, we present Wavelet, the adaptation of the Wave menu for the navigation in multimedia data on iPhone. Its layout, based on an inverted representation of the hierarchy, is particularly well adapted to mobile devices. Indeed, it guarantees that submenus are always displayed on the screen and it supports efficient navigation by providing previsualization of the submenus

Wavelet Menu : Adaptation des Marking Menus pour les Dispositifs Mobiles

National audienceL'exploration et la navigation dans les hiérarchies de données multimédia (photos, musiques, etc.) sont des tâches fréquentes sur dispositifs mobiles. Cependant, l'interaction peut s'en trouver dégradée du fait de la petite taille de l'écran et de l'absence de dispositifs d'entrée précis. Par conséquent, les techniques de menus innovantes conçues pour PC ne sont plus adaptées aux dispositifs mobiles pour naviguer efficacement. Dans cet article, nous présentons le Wavelet menu, l'adaptation du Wave menu pour la navigation dans des données multimédia sur iPhone. Grâce à une représentation inversée de la hiérarchie, il est particulièrement adapté aux dispositifs mobiles. En effet, il garantit que les sous-menus sont toujours affichés à l'écran et la prévisualisation des sous-menus permet une navigation efficace

Leaf Menus: Linear Menus with Stroke Shortcuts for Small Handheld Devices

International audienceThis paper presents Leaf menu, a new type of contextual linear menu that supports curved gesture shortcuts. By providing an alternative to keyboard shortcuts, the Leaf menus can be used for the selection of commands on tabletops, but its key benefit is its adequacy to small handheld touchscreen devices (PDA, Smartphone). Indeed Leaf menus define a compact and known layout inherited from linear menus, they support precise finger interaction, they manage occlusion and they can be used in close proximity to the screen borders. Moreover, by providing stroke shortcuts, they favour the selection of frequent commands in expert mode and make eye-free selection possible

Vegetation patch effects on flow resistance at channel scale

International audienceThanks to a specific experimental design in a controlled channel, this paper aimed at quantifying how patches of four different ditches plant species affect integrated flow resistance parameters, the Manning coefficient. These plants, frequently encountered in the farmland ditches and irrigation channels of the south of France, were selected according to a large range of hydrophilic requirements, flexibility and branching complexity related to the plant blockage factor. Eight different spatial patches (regular, random, lateral or central patches) of each plant with crescent or similar plant densities were implanted at the bottom of a controlled channel where the water levels and water velocities were measured for three different discharges in steady and unsteady flow conditions. Resistance parameters (Manning parameters) were then estimated from the total head-loss, or from flow propagation velocity in the channel thanks to inversion of an hydrodynamic model. These experiments allow us to test the significance effect of channel vegetation patches and densities on flow resistance parameters at the reach scale