Estimation precision of degree of polarization in the presence of signal-dependent and additive Poisson noises

We address precision of estimation of the degree of polarization (DOP) from the orthogonal state contrast image (OSCI) in the presence of both signal-dependent Poisson noise due to useful signal, and additive Poisson noise due to dark current and / or background light. We determine the Cramer Rao Lower Bound and deduce from it figures of merit for DOP estimation. In particular, we show that the additive Poisson noise has larger influence on DOP estimation than on intensity estimation when light is highly polarized

Information and resolution in electromagnetic optical systems

Published versio

Comparative study of the best achievable contrast in scalar, Stokes and Mueller images

We compare the relative performance of different active polarimetric imaging architectures for target detection applications. We show that if the noise that affects the measurements is additive and if the only relevant parameter is the contrast between an object of interest and a background with different Mueller matrices, the most efficient imaging architecture consists in acquiring a single intensity image while optimizing the illumination and analysis states of polarization

SOLID STATE BATTERIES WITH CONDUCTING POLYMERS

Les polymères conducteurs comme (CH)x sont très intéressants comme matériaux d'électrodes dans des cellules électrochimiques. Nous avons combiné de telles électrodes avec des électrolytes solides pour fabriquer des piles "tout solide". Les premiers prototypes utilisant une anode d'argent et un électrolyte solide à conduction Ag+ fonctionnent de façon satisfaisante depuis deux ans. Les performances ont été testées sur de nombreuses cellules pour étudier les propriétés électriques ainsi que les paramètres thermodynamiques. Un grand nombre de cycles charge-décharge ont été enregistrés à diverses valeurs de courant maintenu constant. Ceci a permis de déterminer les propriétés essentielles : tension, courant, densité de courant, fiabilité, rendement faradique, rendement énergétique, etc. Les performances ont été également étudiées en fonction de la température, permettant d'obtenir l'enthalpie et l'entropie de la réaction électrochimique. La cinétique de la décharge a été soigneusement mesurée et comparée aux données de diffusion récemment obtenues dans notre laboratoire à l'aide d'isotopes radioactifs. Ceci a donné une explication claire du mécanisme de transport atomique dans le polymère.The conducting polymers like (CH)x are very interesting materials for electrodes in electrochemical cells. We have combined such electrodes with solid electrolytes to build "all solid-state" batteries. The first prototypes using a silver anode and a silver conducting electrolyte have been working satisfactorily since two years. The performances have been tested with many batteries to study the electrical properties as well as the thermodynamical parameters. A number of cycles of charge-discharge have been recorded at various values of the current kept constant. This has allowed to determine the essential properties : voltage, current, current density, reliability, Faradaic and energetic efficiency ... The performances have also been investigated as a function of temperature, allowing to derive the enthalpy and the entropy of the electrochemical reaction. The kinetics of the discharge has been thorough-fully measured and compared to the mass transport data recently obtained in our laboratory by using radiotracers. This has given a clear explanation of the mechanism of mass transport inside the polymer