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Direct imaging of exoplanet systems requires the use of coronagraphs to reach high contrast levels (10^-8 to 10^-11) at small angular separations (0.1"). However, the performance of these devices is drastically limited by aberrations (in…

Instrumentation and Methods for Astrophysics · Physics 2017-10-11 Johan Mazoyer , Raphaël Galicher , Pierre Baudoz , Patrick Lanzoni , Frédéric Zamkotsian , Gérard Rousset

Detection and characterization of exoplanets by direct imaging requires a coronagraph designed to deliver high contrast at small angular separation. To achieve this, an accurate control of low order aberrations, such as pointing and focus…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Frédéric P. A. Vogt , Frantz Martinache , Olivier Guyon , Takashi Yoshikawa , Kaito Yokochi , Vincent Garrel , Taro Matsuo

One of the challenges for every optical system is preserving the quality of the used beam, which may be significantly reduced, due to the low condition of used optical elements or their misalignment. There are plenty of methods focused on…

The estimation and compensation of quasi-static aberrations is mandatory to reach the ultimate performance of high-contrast imaging systems. COFFEE is a focal plane wave-front sensing method that consists in the extension of phase diversity…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 B. Paul , L. M. Mugnier , J. -F. Sauvage , K. Dohlen

Articular cartilage is a musculoskeletal soft tissue renowned for its unique mechanical properties. Understanding both its hierarchical structure and the interplay between its constituents could shed light on the mechanical competence of…

Medical Physics · Physics 2025-10-17 Simone Fantoni , Luca Brombal , Paolo Cardarelli , Fabio Baruffaldi

Spatial mode sorting has come to prominence as an optical processing modality capable of saturating fundamental limits to numerous sensing tasks including wavefront sensing, coronagraphy, and superresolution imaging. But despite their…

Optics · Physics 2025-10-28 Jacob Trzaska , Amit Ashok

The observation of vortices in superconductors was a major breakthrough in developing the conceptual background for superconducting applications. Each vortex carries a flux quantum, and the magnetic field radially decreases from the center.…

Superconductivity · Physics 2016-06-22 H. Suderow , I. Guillamon , J. G. Rodrigo , S. Vieira

Low fluence illumination sources can facilitate clinical transition of photoacoustic imaging because they are rugged, portable, affordable, and safe. However, these sources also decrease image quality due to their low fluence. Here, we…

Image and Video Processing · Electrical Eng. & Systems 2020-04-21 Ali Hariri , Kamran Alipour , Yash Mantri , Jurgen P. Schulze , Jesse V. Jokerst

Context. Since 1995 and the first discovery of an exoplanet orbiting a main-sequence star, 4000 exoplanets have been discovered using several techniques. However, only a few of these exoplanets were detected through direct imaging. Indeed,…

Instrumentation and Methods for Astrophysics · Physics 2020-07-01 Axel Potier , Raphaël Galicher , Pierre Baudoz , Elsa Huby , Julien Milli , Zahed Wahhaj , Anthony Boccaletti , Arthur Vigan , Mamadou N'Diaye , Jean-François Sauvage

Rather than using an adaptive optics (AO) system to correct a telescope s entire pupil, it can instead be used to more finely correct a smaller sub-aperture. Indeed, existing AO systems can be used to correct a sub-aperture 1/3 to 1/2 the…

Astrophysics · Physics 2009-11-13 E. Serabyn , K. Wallace , M. Troy , B. Mennesson , P. Haguenauer , R. Gappinger , R. Burruss

Optical stellar interferometers have demonstrated milli-arcsecond resolution with few apertures spaced hundreds of meters apart. To obtain rich direct images, many apertures will be needed, for a better sampling of the incoming wavefront.…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha , Antoine Labeyrie

High-contrast imaging will be a challenge for future ELTs, because their vibrations create low-order aberrations - mostly tip/tilt - that reduce coronagraphic performances at 1.2 lambda/D and above. A Low-Order WaveFront Sensor (LOWFS) is…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Julien Lozi , Ruslan Belikov , Glenn Schneider , Olivier Guyon , EugenePluzhnik , Sandrine J. Thomas , Frantz Martinache

The 2020 Decadal Survey on Astronomy and Astrophysics endorsed space-based high contrast imaging for the detection and characterization of habitable exoplanets as a key priority for the upcoming decade. To advance the maturity of starlight…

We propose an imaging system and methodology for mapping soft-tissue samples in three dimensions, with micron-scale and isotropic spatial resolution, with low-concentrations as well as in the absence of heavy metal staining. We used hard…

Instrumentation and Detectors · Physics 2023-12-21 Michela Esposito , Nicole Schieber , Alessandro Olivo , Yannick Schwab , Marco Endrizzi

Top sensitivity Ring Laser Gyroscopes based on a simple mechanical scheme, so called heterolithic, have shown to operate on a continuous basis; since the mirror positions are not fixed, unwanted signals can occur, and data selection is…

Coronagraphy is an efficient technique for identifying and characterizing extra-solar planets orbiting in the habitable zone of their parent star. An important family of coronagraphs is based on amplitude or phase filters placed at an…

Instrumentation and Methods for Astrophysics · Physics 2022-08-30 Francçois Henault

Although many exoplanets have been indirectly detected over the last years, direct imaging of them with ground-based telescopes remains challenging. In the presence of atmospheric fluctuations, it is ambitious to resolve the high brightness…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 Jakob Roth , Gianluca Li Causi , Vincenzo Testa , Philipp Arras , Torsten A. Enßlin

Properly apodized pupils can deliver point spread functions (PSFs) free of Airy rings, and are suitable for high dynamical range imaging of extrasolar terrestrial planets (ETPs). To reach this goal, classical pupil apodization (CPA)…

Astrophysics · Physics 2007-05-23 E. A. Pluzhnik , O. Guyon , S. T. Ridgway , F. Martinache , R. A. Woodruff , C. Blain , R. Galicher

Flux vortices in superconductors can be imaged using transmission electron microscopy because the electron beam is deflected by the magnetic flux associated with the vortices. This technique has a better spatial and temporal resolution than…

Superconductivity · Physics 2009-10-31 J. C. Loudon , P. A. Midgley

We present a study of Lyot style (i.e., classical, band-limited, and Gaussian occulter) coronagraphy on extremely large, highly-segmented telescopes. We show that while increased telescope diameter is always an advantage for high dynamic…

Astrophysics · Physics 2009-11-11 Anand Sivaramakrishnan , Natalia Yaitskova
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