Bound states in the continuum in symmetric and asymmetric photonic crystal slabs

We develop a semi-analytical model to describe bound states in the continuum (BICs) in photonic crystal slabs. We model leaky modes supported by photonic crystal slabs as a transverse Fabry-Perot resonance composed of a few propagative Bloch waves bouncing back and forth vertically inside the slab. This multimode Fabry-Perot model accurately predicts the existence of BICs and their positions in the parameter space. We show that, regardless of the slab thickness, BICs cannot exist below a cut-off frequency, which is related to the existence of the second-order Bloch wave in the photonic crystal. Thanks to the semi-analyticity of the model, we investigate the dynamics of BICs with the slab thickness in symmetric and asymmetric photonic crystal slabs. We evidence that the symmetry-protected BICs that exist in symmetric structures at the {\Gamma}-point of the dispersion diagram can still exist when the horizontal mirror symmetry is broken, but only for particular values of the slab thickness

Etude morphologique et métrologique des sinus de Valsalva par traitement d'images tomographiques

L'objectif de cette thèse est l'élaboration et l'application de traitements d'images pour permettre une étude objective et fiable des sinus de Valsalva, importantes cavités de la base de l'aorte. Les méthodes proposées s'appliquent aux séquences ciné-IRM et aux examens de scanner sans qu'il n'y ait à modifier le paramétrage entre deux examens. Pour cela, nous avons d'abord étudié la morphologie de cette zone anatomique puis détaillé les différentes propriétés communes à toutes les images de sinus. Ceux-ci font en l'occurrence partie des principaux organes clairs et peu mobiles. Nous avons donc développé un algorithme qui détecte ces éléments et caractérise chacun d'entre eux par une trajectoire unique. Divers outils de morphologie mathématique ont été utilisés à cette occasion, tout comme pour l'extraction du contour des sinus dans chaque image. L'étape de segmentation repose elle sur la reconstruction géodésique, qui s'avère plus efficace et surtout plus robuste que l'usage de contours actifs usuels. L'intérieur des sinus forme un domaine simplement connexe et étoilé. Grâce à ce postulat, nous avons conçu une nouvelle reconstruction, nommée transformée en aurore, qui limite la propagation des intensités aux supports radiaux et présente les résultats dans un repère polaire pour une meilleure lecture des contours.Les points caractéristiques des sinus ont également été détectés, par étude de rayons et détermination de points dominants. Ces points fournissent les éléments nécessaires à une mesure automatique des sinus, mesure cohérente avec les mesures actuellement réalisées manuellement et les variations intra et inter-observateurs de celles-ci. D'autres outils sont enfin esquissés pour modéliser le contour par coniques, classer les images d'examens cinétiques en fonction du moment du cycle et suivre le mouvement des valves dans ces mêmes examens.L'ensemble de ces travaux ont amené à la réalisation d'un logiciel d'aide au diagnostic qui intègre nos méthodes et dont l'interface est également présentée dans le présent mémoire.This Phd thesis deals with the design and the use of image processing tools in order to allow a reliable and objective study of the sinuses of Valsalva which are important cavities of the aortic root. The proposed methods can be applied on cine-MR sequences and CT examinations without any change in the settings between two examinations.Firstly, we studied the morphology of this anatomical area and its constant properties in all images of the dataset. Sinuses are one of the main bright organs with limited movements. Hence a new algorithm has been designed. It detects and characterizes each bright organ by a single trajectory. Various tools of mathematical morphology are used for this step, as for the extraction of the contour of the sinuses in each image.The segmentation step is based on the geodesic reconstruction, which is more effective and more robust than the usual active contours. The shape depicting the sinuses is simply connected and a star domain. With this assumption, a new reconstruction is proposed, called the Aurora transform. This transform limits the spread of intensities only on the radial lines and shows its results in a polar space for a better reading of edges.The relevant points of the sinuses are also detected by a study of radii and the determination of dominant points along edges. An automatic measurement of the sinuses is deduced from these points. The values are very close to the manual measures currently done according to the intra-and inter-observer variations.Some other tools are finally outlined. They includes the modeling of edges by conics, the image classification depending on the time of the cycle in sequences and the tracking of the aortic valves in these examinations.This work led to the devlopement of a diagnostic aid software based on our methods. Its interface is also presented herein.DIJON-BU Doc.électronique (212319901) / SudocSudocFranceF

Zero-velocity atom interferometry using a retroreflected frequency chirped laser

International audienceAtom interferometry using stimulated Raman transitions in a retroreflected configuration is the first choice in high-precision measurements because it provides low phase noise, a high-quality Raman wave front, and a simple experimental setup. However, it cannot be used for atoms at zero velocity because two pairs of Raman lasers are simultaneously resonant. Here we report a method which allows this degeneracy to be lifted by using a frequency chirp on the Raman lasers. Using this technique, we realize a Mach-Zehnder atom interferometer hybridized with a force balanced accelerometer which provides horizontal acceleration measurements with a short-term sensitivity of 3.2×10−5ms−2/Hz. This technique could be used for multiaxis inertial sensors, tiltmeters, or atom interferometry in a microgravity environment

Optical electron transfer through 2,7-diethynylfluorene spacers in mixed-valent complexes containing electron-rich "(η2-dppe)(η5-C5Me5)Fe" endgroups.

International audienceWe report in this communication the study of the intramolecular electron transfer through a 2,7-diethynylfluorenyl spacer in the Fe(II)/Fe(III) mixed-valent (MV) complex [(η(2)-dppe)(η(5)-C(5)Me(5))FeC≡C(2,7-C(21)H(24))C≡CFe(η(5)-C(5)Me(5))(η(2)-dppe)][PF(6)] (1[PF(6)]). The complex is generated in situ by comproportionation from its homovalent dinuclear Fe(II) and Fe(III) parents (1 and 1[PF(6)](2)). It is shown that electronic delocalization is much more effective through a 2,7-fluorenyl than through a 4,4'-biphenyl bridging unit

Absolute airborne gravimetry with a cold atom sensor

Measuring gravity from an aircraft is essential in geodesy, geophysics and exploration. Today, only relative sensors are available for airborne gravimetry. This is a major drawback because of the calibration and drift estimation procedures which lead to important operational constraints and measurement errors. Here, we report an absolute airborne gravimeter based on atom interferometry. This instrument has been first tested on a motion simulator leading to gravity measurements noise of 0.3 mGal for 75 s filtering time constant. Then, we realized an airborne campaign across Iceland in April 2017. From a repeated line and crossing points, we obtain gravity measurements with an estimated error between 1.7 and 3.9 mGal. The airborne measurements have also been compared to upward continued ground gravity data and show differences with a standard deviation ranging from 3.3 to 6.2 mGal and a mean value ranging from-0.7 mGal to-1.9 mGal

Time domain simulation of electromagnetic cloaking structures with TLM method

This paper was published in Optic Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OE.16.006461The increasing interest in invisible cloaks has been prompted in part by the availability of powerful computational resources which permit numerical studies of such a phenomenon. These are usually carried out with commercial software. We report here a full time domain simulation of cloaking structures with the Transmission Line Modeling (TLM) method. We first develop a new condensed TLM node to model metamaterials in two dimensional situations; various results are then presented, with special emphasis on what is not easily achievable using commercial software.This work has been supported in part by the “Ministerio de Educación y Ciencia” of Spain under research projects No. FIS2004-03273 and FIS2007-63293 cofinanced with FEDER funds of the European Union

The NAOMI GAZL multispecies differential absorption lidar: realization and testing on the TADI gas leak simulation facility

International audienceWe report on a differential absorption lidar, designed for remote detection of CH 4 and CO 2 , based on a single-frequency 1.57-1.65 µm parametric oscillator/amplifier system. The lidar is tested on a controlled gas release facility

Present eternity : quests of temporality in the literary production of the "extrême contemporain" in France (The Writings of Dominique Fourcade and Emmanuel Hocquard)

The term \uab extr\ueame contemporain \ubb is an expression currently used by scholars to indicate the French literary production of the last 20 years. This term was used in a work of literature for the first time by the French poet Dominique Fourcade in 1986 (\uc9l\ue9gie L apostrophe E.C.) in reference to an epoch, but also to a new sense of experiencing time and space in the so-called \uab age of digital reproducibility \ubb. The aim of this paper is to consider how the change in temporal protocols due to the triumph of Big Optics (Paul Virilio) affects the sense of teleology (destiny) and the quest for experience in French contemporary poetry (in particular, in the genre of the elegy). Including both memory and anticipation, the \uab extr\ueame contemporain \ubb production seems to prefer the \u201ctime of now\u201d, Jetz-zeit in Benjamin\u2019s words, to past or testimony, and speaks to the present, whose responsibility is to give voice to a space where everything is simply allowed to happen

Synopsis of the pelidnotine scarabs (Coleoptera, Scarabaeidae, Rutelinae, Rutelini) and annotated catalog of the species and subspecies

The pelidnotine scarabs (Scarabaeidae: Rutelinae: Rutelini) are a speciose, paraphyletic assemblage of beetles that includes spectacular metallic species (“jewel scarabs”) as well as species that are ecologically important as herbivores, pollinators, and bioindicators. These beetles suffer from a complicated nomenclatural history, due primarily to 20th century taxonomic and nomenclatural errors. We review the taxonomic history of the pelidnotine scarabs, present a provisional key to genera with overviews of all genera, and synthesize a catalog of all taxa with synonyms, distributional data, type specimen information, and 107 images of exemplar species. As a result of our research, the pelidnotine leaf chafers (a paraphyletic group) include 27 (26 extant and 1 extinct) genera and 420 valid species and subspecies (419 extant and 1 extinct). Our research makes biodiversity research on this group tractable and accessible, thus setting the stage for future studies that address evolutionary and ecological trends. Based on our research, 1 new species is described, 1 new generic synonym and 12 new species synonyms are proposed, 11 new lectotypes and 1 new neotype are designated, many new or revised nomenclatural combinations, and many unavailable names are presented. The following taxonomic changes are made: New generic synonym: The genus Heteropelidnota Ohaus, 1912 is a new junior synonym of Pelidnota MacLeay, 1819. New species synonyms: Plusiotis adelaida pavonacea Casey, 1915 is a syn. n. of Chrysina adelaida (Hope, 1841); Odontognathus gounellei Ohaus, 1908 is a revised synonym of Pelidnota ebenina (Blanchard, 1842); Pelidnota francoisgenieri Moore & Jameson, 2013 is a syn. n. of Pelidnota punctata (Linnaeus, 1758); Pelidnota genieri Soula, 2009 is a syn. n. of Pelidnota punctata (Linnaeus, 1758); Pelidnota lutea (Olivier, 1758) is a revised synonym of Pelidnota punctata (Linnaeus, 1758); Pelidnota (Pelidnota) texensis Casey, 1915 is a revised synonym of Pelidnota punctata (Linnaeus, 1758); Pelidnota (Strigidia) zikani (Ohaus, 1922) is a revised synonym of Pelidnota tibialis tibialis Burmeister, 1844; Pelidnota ludovici Ohaus, 1905 is a syn. n. of Pelidnota burmeisteri tricolor Nonfried, 1894; Rutela fulvipennis Germar, 1824 is syn. n. of Pelidnota cuprea (Germar, 1824); Pelidnota pulchella blanda Burmeister, 1844 is a syn. n. of Pelidnota pulchella pulchella (Kirby, 1819); Pelidnota pulchella scapularis Burmeister, 1844 is a syn. n. of Pelidnota pulchella pulchella (Kirby, 1819); Pelidnota xanthogramma Perty, 1830 is a syn. n. of Pelidnota pulchella pulchella (Kirby, 1819). New or revised statuses: Pelidnota fabricelavalettei Soula, 2009, revised status, is considered a species; Pelidnota rioensis Soula, 2009, stat. n., is considered a species; Pelidnota semiaurata semiaurata Burmeister, 1844, stat. rev., is considered a subspecies. New or comb. rev. and revised status: Plusiotis guaymi Curoe, 2001 is formally transferred to the genus Chrysina (C. guaymi (Curoe, 2001), comb. n.); Plusiotis transvolcanica Morón & Nogueira, 2016 is transferred to the genus Chrysina (C. transvolcanica (Morón & Nogueira, 2016), comb. n.). Heteropelidnota kuhnti Ohaus, 1912 is transferred to the genus Pelidnota (P. kuhnti (Ohaus, 1912), comb. n.); Odontognathus riedeli Ohaus, 1905 is considered a subspecies of Pelidnota rubripennis Burmeister, 1844 (Pelidnota rubripennis riedeli (Ohaus, 1905), revised status and comb. rev.); Pelidnota (Strigidia) acutipennis (F. Bates, 1904) is transferred to the genus Sorocha (Sorocha acutipennis (F. Bates, 1904), comb. rev.); Pelidnota (Odontognathus) nadiae Martínez, 1978 is transferred to the genus Sorocha (Sorocha nadiae (Martínez, 1978), comb. rev.); Pelidnota (Ganonota) plicipennis Ohaus, 1934 is transferred to the genus Sorocha (Sorocha plicipennis (Ohaus, 1934), comb. rev.); Pelidnota similis Ohaus, 1908 is transferred to the genus Sorocha (Sorocha similis (Ohaus, 1908), comb. rev.); Pelidnota (Ganonota) yungana Ohaus, 1934 is transferred to Sorocha (Sorocha yungana (Ohaus, 1934), comb. rev.); Pelidnota malyi Soula, 2010: 58, revised status; Xenopelidnota anomala porioni Chalumeau, 1985, revised subspecies status. To stabilize the classification of the group, a neotype is designated for the following species: Pelidnota thiliezi Soula, 2009. Lectotypes are designated for the following names (given in their original combinations): Pelidnota brevicollis Casey, 1915, Pelidnota brevis Casey, 1915, Pelidnota debiliceps Casey, 1915, Pelidnota hudsonica Casey, 1915, Pelidnota oblonga Casey, 1915, Pelidnota pallidipes Casey, 1915, Pelidnota ponderella Casey, 1915, Pelidnota strenua Casey, 1915, Pelidnota tarsalis Casey, 1915, Pelidnota texensis Casey, 1915, and Scarabaeus punctatus Linnaeus, 1758. The following published infrasubspecific names are unavailable per ICZN Article 45.6.1: Pelidnota (Odontognathus) cuprea var. coerulea Ohaus, 1913; Pelidnota (Odontognathus) cuprea var. rufoviolacea Ohaus, 1913; Pelidnota (Odontognathus) cuprea var. nigrocoerulea Ohaus, 1913; Pelidnota pulchella var. fulvopunctata Ohaus, 1913; Pelidnota pulchella var. sellata Ohaus, 1913; Pelidnota pulchella var. reducta Ohaus, 1913; Pelidnota unicolor var. infuscata Ohaus, 1913. The following published species name is unavailable per ICZN Article 11.5: Neopatatra synonyma Moore & Jameson, 2013. The following published species name is unavailable per application of ICZN Article 16.1: Parhoplognathus rubripennis Soula, 2008. Synopsis of the pelidnotine scarabs (Coleoptera, Scarabaeidae, Rutelinae, Rutelini) 3 The following published species name is unavailable per application of ICZN Article 16.4.1: Strigidia testaceovirens argentinica Soula, 2006, Pelidnota (Strigidia) testaceovirens argentinica (Soula, 2006), and Pelidnota testaceovirens argentinica (Soula, 2006). The following published species names are unavailable per application of ICZN Article 16.4.2: Homonyx digennaroi Soula, 2010; Homonyx lecourti Soula, 2010; Homonyx mulliei Soula, 2010; Homonyx simoensi Soula, 2010; Homonyx wagneri Soula, 2010; Homonyx zovii Demez & Soula, 2011; Pelidnota arnaudi Soula, 2009; Pelidnota brusteli Soula, 2010; Pelidnota chalcothorax septentrionalis Soula, 2009; Pelidnota degallieri Soula, 2010; Pelidnota lavalettei Soula, 2008; Pelidnota lavalettei Soula, 2009; Pelidnota dieteri Soula, 2011; Strigidia gracilis decaensi Soula, 2008, Pelidnota (Strigidia) gracilis decaensi (Soula, 2008), and Pelidnota gracilis decaensi (Soula, 2008); Pelidnota halleri Demez & Soula, 2011; Pelidnota injantepalominoi Demez & Soula, 2011; Pelidnota kucerai Soula, 2009; Pelidnota malyi Soula, 2010: 36-37; Pelidnota mezai Soula, 2009; Pelidnota polita darienensis Soula, 2009; Pelidnota polita orozcoi Soula, 2009; Pelidnota polita pittieri Soula, 2009; Pelidnota punctulata decolombia Soula, 2009; Pelidnota punctulata venezolana Soula, 2009; Pelidnota raingeardi Soula, 2009; Pelidnota schneideri Soula, 2010; Pelidnota simoensi Soula, 2009; Pelidnota unicolor subandina Soula, 2009; Sorocha carloti Demez & Soula, 2011; Sorocha castroi Soula, 2008; Sorocha fravali Soula, 2011; Sorocha jeanmaurettei Demez & Soula, 2011; Sorocha yelamosi Soula, 2011; Xenopelidnota bolivari Soula, 2009; Xenopelidnota pittieri pittieri Soula, 2009. Due to unavailability of the name Pseudogeniates cordobaensis Soula 2009, we describe the species as intentionally new (Pseudogeniates cordobaensis Moore, Jameson, Garner, Audibert, Smith, and Seidel, sp. n.)