Les caractères dans le théâtre de Sade : la loi du genre

Pour Sade, le théâtre est surtout une activité sociale, un moyen de se situer vis-à-vis du monde. Au contraire des écrivains tels que Diderot et Beaumarchais, Sade n’est pas un innovateur dramatique, mais s’il ne met pas en question les genres traditionnels et même récents, c’est afin de les manipuler, de jouer avec. Une analyse de deux pièces — Le misanthrope par amour et Le capricieux — permet de mieux comprendre le rapport de Sade avec la tradition théâtrale, et de voir comment cet auteur profite des règles et attentes dramatiques.Theatre for Sade is above all a social activity, a means of positioning oneself in relation to the world. Unlike playwrights such as Diderot and Beaumarchais, Sade is no dramatic innovator, but if he does not question the traditional and even recent genres, he does so in order to manipulate them, to play with them. A close analysis of two plays—Le misanthrope par amour and Le capricieux—allows for a clearer understanding of Sade's relationship with his theatrical heritage, and to see how this author profits from dramatic rules and expectations

Lyot-based Ultra-Fine Pointing Control System for Phase Mask Coronagraphs

High performance coronagraphic imaging at small inner working angle requires efficient control of low order aberrations. The absence of accurate pointing control at small separation not only degrades coronagraph starlight rejection but also increases the risk of confusing planet's photons with starlight leaking next to the coronagraph focal plane mask center. Addressing this issue is essential for preventing coronagraphic leaks, and we have thus developed a new concept, the Lyot-based pointing control system (LPCS), to control pointing errors and other low order aberrations within a coronagraph. The LPCS uses residual starlight reflected by the Lyot stop at the pupil plane. Our simulation has demonstrated pointing errors measurement accuracy between 2-12 nm for tip-tilt at 1.6 micron with a four quadrant phase mask coronagraph.Comment: 7 pages, 5 figures, Proceedings of AO4ELTs3 conference, Paper 12667, Florence, Italy, May 201

Lyot-based Low Order Wavefront Sensor for Phase-mask Coronagraphs: Principle, Simulations and Laboratory Experiments

High performance coronagraphic imaging of faint structures around bright stars at small angular separations requires fine control of tip, tilt and other low order aberrations. When such errors occur upstream of a coronagraph, they results in starlight leakage which reduces the dynamic range of the instrument. This issue has been previously addressed for occulting coronagraphs by sensing the starlight before or at the coronagraphic focal plane. One such solution, the coronagraphic low order wave-front sensor (CLOWFS) uses a partially reflective focal plane mask to measure pointing errors for Lyot-type coronagraphs. To deal with pointing errors in low inner working angle phase mask coronagraphs which do not have a reflective focal plane mask, we have adapted the CLOWFS technique. This new concept relies on starlight diffracted by the focal plane phase mask being reflected by the Lyot stop towards a sensor which reliably measures low order aberrations such as tip and tilt. This reflective Lyot-based wavefront sensor is a linear reconstructor which provides high sensitivity tip-tilt error measurements with phase mask coronagraphs. Simulations show that the measurement accuracy of pointing errors with realistic post adaptive optics residuals are approx. 10^-2 lambda/D per mode at lambda = 1.6 micron for a four quadrant phase mask. In addition, we demonstrate the open loop measurement pointing accuracy of 10^-2 lambda/D at 638 nm for a four quadrant phase mask in the laboratory.Comment: 9 Pages, 11 Figures, to be published in PASP June 2014 issu

Avant-propos

Le théâtre de la Révolution française constitue, aujourd’hui encore, une énigme et un hapax. Hapax, parce que jamais dans l’histoire du théâtre on n’a vu une telle explosion de créativité: les salles se sont multipliées jusqu’à atteindre une quarantaine pour la seule ville de Paris; les pièces nouvelles sont légion, les auteurs fourmillent, le public est souvent passionné. Énigme, parce que, plus qu’à aucune époque de l’histoire du théâtre, ce qui en lui était éphémère, essentiellement théâtr..

Pour qu'on se souvienne du théâtre que faisait Jean-Luc Lagarce.

Conversation avec Bernard Bloch, un jour de novembre Propos recueillis par Pierre Frantz On se coucherait pour toujours, on dirait qu’on est malade... Bernard Bloch a joué le rôle d'Argan dans Le Malade imaginaire qu'a monté Jean-Luc Lagarce en 1993. Ce spectacle a eu 150 représentations, en France et dans l'est de l’Allemagne. Pierre Frantz : Qu'est-ce que c'était, pour toi de jouer le malade dans la mise en scène de Lagarce ? Bernard Bloch : C'est l'histoire d'une inversion permanente entre..

Le théâtre déstabilisé. Diderot et la critique de Rousseau

La question de la cohérence de l’oeuvre et de la pensée de Diderot est souvent posée dès lors qu’on aborde le champ du théâtre et de la morale. S’il est sans doute caricatural de voir en lui un auteur qui se contredit, des dissonances se font entendre distinctement entre sa théorie du théâtre, ses pièces dans les années 1757-1758 et, d’autre part, ses écrits plus tardifs, le Salon de 1767, Paradoxe sur le comédien. Est-il bon ? Est-il méchant ? Elles concernent le coeur même de la théorie morale du théâtre et interrogent les notions de pathétique ou de pitié, centrales dans le projet de Diderot et même dans celui des Lumières (chez Lessing, Mercier, Marmontel ou Beaumarchais). Sans renoncer pour autant à l’espoir d’une efficacité sensible et morale du théâtre, Diderot en rabat de moitié sur sa portée, repense son esthétique et y introduit la distance. C’est au choc provoqué par la Lettre à d’Alembert et par la critique virulente de Rousseau qu’il faut attribuer cet approfondissement décisif de la pensée du théâtre chez Diderot. Son esthétique est alors cohérente avec son art et sa pensée morale, telle que nous la lisons de La Religieuse à l’Essai sur les règnes de Claude et de NéronDestabilized Theatre. Diderot and Rousseau’s CriticismThe question of the coherence of Diderot’swork and thought is often posed in relation to his theatre and moral thought. While it would no doubt be going too far to say that he contradicts himself, there is a clear difference between his dramatic theory and 1757-58 plays on the one hand, and on the other his later writings, the 1767 Salon, the Paradoxe sur le comédien, Est-il bon ? Est-il méchant ? It concerns the very heart of his moral theory of the theatre and the notions of the pathetic and pity, which are central to Diderot’s project, as to that of the Enlightenment (Lessing, Mercier, Marmontel or Beaumarchais). Without abandoning hope of theatre’s sensitive and moral effectiveness, Diderot reduces its scope, re-thinking its æsthetics and introducing distance. This decisive development of Diderot’s dramatic theory can be attributed to the shock caused by the BLetter to d’AlembertB and Rousseau’s violent criticism. This æsthetic thinking corresponds to his art and moral thought as it is expressed in the works from La Religieuse to the Essai sur les règnes de Claude et de Néro

Lyot-based Low Order Wavefront Sensor: Implementation on the Subaru Coronagraphic Extreme Adaptive Optics System and its Laboratory Performance

High throughput, low inner working angle (IWA) phase masks coronagraphs are essential to directly image and characterize (via spectroscopy) earth-like planets. However, the performance of low-IWA coronagraphs is limited by residual pointing errors and other low-order modes. The extent to which wavefront aberrations upstream of the coronagraph are corrected and calibrated drives coronagraphic performance. Addressing this issue is essential for preventing coronagraphic leaks, thus we have developed a Lyot-based low order wave front sensor (LLOWFS) to control the wavefront aberrations in a coronagraph. The LLOWFS monitors the starlight rejected by the coronagraphic mask using a reflective Lyot stop in the downstream pupil plane. The early implementation of LLOWFS at LESIA, Observatoire de Paris demonstrated an open loop measurement accuracy of 0.01 lambda/D for tip-tilt at 638 nm when used in conjunction with a four quadrant phase mask (FQPM) in the laboratory. To further demonstrate our concept, we have installed the reflective Lyot stops on the Subaru Coronagraphic Extreme AO (SCExAO) system at the Subaru Telescope and modified the system to support small IWA phase mask coronagraphs (< 1 lambda/D) on-sky such as FQPM, eight octant phase mask, vector vortex coronagraph and the phase induced amplitude apodization complex phase mask coronagraph with a goal of obtaining milli arc-second pointing accuracy. Laboratory results have shown the measurement of tip, tilt, focus, oblique and right astigmatism at 1.55 um for the vector vortex coronagraph. Our initial on-sky result demonstrate the closed loop accuracy of < 7 x 10-3 lambda/D at 1.6 um for tip, tilt and focus aberrations with the vector vortex coronagraph.Comment: 9 pages, 9 Figures, Proc. of SPIE Astronomical Telescopes + Instrumentation 201

On-sky demonstration of low-order wavefront sensing and control with focal plane phase mask coronagraphs

The ability to characterize exoplanets by spectroscopy of their atmospheres requires direct imaging techniques to isolate planet signal from the bright stellar glare. One of the limitations with the direct detection of exoplanets, either with ground- or space-based coronagraphs, is pointing errors and other low-order wavefront aberrations. The coronagraphic detection sensitivity at the diffraction limit therefore depends on how well low-order aberrations upstream of the focal plane mask are corrected. To prevent starlight leakage at the inner working angle of a phase mask coronagraph, we have introduced a Lyot-based low-order wavefront sensor (LLOWFS), which senses aberrations using the rejected starlight diffracted at the Lyot plane. In this paper, we present the implementation, testing and results of LLOWFS on the Subaru Coronagraphic Extreme Adaptive Optics system (SCExAO) at the Subaru Telescope. We have controlled thirty-five Zernike modes of a H-band vector vortex coronagraph in the laboratory and ten Zernike modes on sky with an integrator control law. We demonstrated a closed-loop pointing residual of 0.02 mas in the laboratory and 0.15 mas on sky for data sampled using the minimal 2-second exposure time of the science camera. We have also integrated the LLOWFS in the visible high-order control loop of SCExAO, which in closed-loop operation has validated the correction of the non-common path pointing errors between the infrared science channel and the visible wavefront sensing channel with pointing residual of 0.23 mas on sky.Comment: 12 pages, 15 figures, Accepted and scheduled for publication in September 2015 issue of the PAS