English
Related papers

Related papers: Phase-induced amplitude apodization complex mask c…

200 papers

Analyser-Based Phase-Contrast imaging (ABPCI) is a phase-contrast imaging method that produces high contrast images of weakly absorbing materials. However, it is only sensitive to phase variations lying in the diffraction plane of the…

Medical Physics · Physics 2021-02-11 M. C. Chalmers , M. J. Kitchen , K. Uesugi , G. Falzon , P. Quin , K. M. Pavlov

Context. In the context of direct imaging of exoplanets, coronagraphs are commonly proposed to reach the required very high contrast levels. However, wavefront aberrations induce speckles in their focal plane and limit their performance.…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Johan Mazoyer , Pierre Baudoz , Raphaël Galicher , Gérard Rousset

We introduce MOSAIC (Masked Objective with Selective Adaptation for In-domain Contrastive learning), a multi-stage framework for domain adaptation of text embedding models that incorporates joint domain-specific masked supervision. Our…

Computation and Language · Computer Science 2026-01-30 Vera Pavlova , Mohammed Makhlouf

We present a publicly available software package developed for exploring apodized pupil Lyot coronagraph (APLC) solutions for various telescope architectures. In particular, the package optimizes the apodizer component of the APLC for a…

In astronomy or biological imaging, refractive index inhomogeneities of e.g. atmosphere or tissues induce optical aberrations which degrade the desired information hidden behind the medium. A standard approach consists in measuring these…

Optics · Physics 2023-06-01 Tengfei Wu , Marc Guillon , Gilles Tessier , Pascal Berto

The realization that direct imaging of extrasolar planets could be technologically feasible within the next decade or so has inspired a great deal of recent research into high-contrast imaging. We ourselves have contributed several design…

Astrophysics · Physics 2009-11-10 N. Jeremy Kasdin , Robert J. Vanderbei , Michael G. Littman , David N. Spergel

Exoplanet imaging and spectroscopy are now routinely achieved by dedicated instruments on large ground-based observatories (e.g. Gemini/GPI, VLT/SPHERE, or Subaru/SCExAO). In addition to extreme adaptive optics (ExAO) and post-processing…

Instrumentation and Methods for Astrophysics · Physics 2019-03-19 Mamadou N'Diaye , Kevin Fogarty , Rémi Soummer , Alexis Carlotti , Kjetil Dohlen , Johan Mazoyer , Laurent Pueyo , Kathryn St. Laurent , Neil Zimmerman

Combining tunable metasurfaces with chaotic cavities opens new avenues for finely tailored dynamic control of microwaves with programmable coding metacavities (PCMs). There is currently a strong interest in utilizing PCMs to overcome the…

Applied Physics · Physics 2020-04-28 Philipp del Hougne , Matthieu Davy , Ulrich Kuhl

We describe the coronagraphic upgrade underway for the Mid-Infrared Array Camera-5 (MIRAC-5) to be used with the 6.5-m MMT telescope utilizing the new MMT Adaptive optics exoPlanet characterization System (MAPS). Mid-IR ground-based…

The new frontier in the quest for the highest contrast levels in the focal plane of a coronagraph is now the correction of the large diffractive artifacts effects introduced at the science camera by apertures of increasing complexity. The…

Instrumentation and Methods for Astrophysics · Physics 2016-01-18 Johan Mazoyer , Laurent Pueyo , Colin Norman , Mamadou N'Diaye , Roeland P. van der Marel , Rémi Soummer

Future high-contrast imaging spectroscopy with a large segmented telescope will be able to detect atmospheric molecules of Earth-like planets around G- or K-type main-sequence stars. Increasing the number of target planets will require a…

Instrumentation and Methods for Astrophysics · Physics 2022-05-25 Satoshi Itoh , Taro Matsuo

Context: The detection and characterization of Earth-like exoplanets (exoEarths) from space requires exquisite wavefront stability at contrast levels of $10^{-10}$. On segmented telescopes in particular, aberrations induced by cophasing…

Direct imaging of Earth-like planets from space requires dedicated observatories, combining large segmented apertures with instruments and techniques such as coronagraphs, wavefront sensors, and wavefront control in order to reach the high…

A large number of coronagraphs have been proposed to overcome the ratio that exists between the star and its planet. The planet finder of the Extremely Large Telescope, which is called EPICS, will certainly need a more efficient coronagraph…

Astrophysics · Physics 2009-11-13 P. Baudoz , R. Galicher , J. Baudrand , A. Boccaletti

Gaussian aperture pupil masks (GAPMs) can in theory achieve the contrast requisite for directly imaging an extrasolar planet around a nearby solar type star. We outline the process of designing, fabricating, and testing a GAPM for use on…

Astrophysics · Physics 2009-11-10 J. H. Debes , J. Ge

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

The future Habitable Worlds Observatory aims to characterize the atmospheres of rocky exoplanets around solar-type stars. The vector vortex coronagraph (VVC) is a main candidate to reach the required contrast of $10^{-10}$. However, the VVC…

Instrumentation and Methods for Astrophysics · Physics 2023-09-06 David S. Doelman , Mireille Ouellet , Axel Potier , Garreth Ruane , Kyle van Gorkom , Sebastiaan Y. Haffert , Ewan S. Douglas , Frans Snik

Direct imaging of Earth-like planets is one of the main science cases for the next generation of extremely large telescopes. This is very challenging due to the star-planet contrast that must be overcome. Most current high-contrast imaging…

Instrumentation and Methods for Astrophysics · Physics 2023-05-03 S. Y. Haffert , J. R. Males , K. Ahn , K. Van Gorkom , O. Guyon , L. M. Close , J. D. Long , A. D. Hedglen , L. Schatz , M. Kautz , J. Lumbres , A. Rodack , J. M. Knight , K. Miller

CONTEXT: The four-quadrant phase mask stellar coronagraph, introduced by D. Rouan et al., is capable of achieving very high dynamical range imaging and was studied in the context of the direct detection of extra-solar planets. Achromatic…

We present the final results of the Apodized Pupil Lyot Coronagraph (APLC) on the High-contrast imager for Complex Aperture Telescopes (HiCAT) testbed, under NASA's Strategic Astrophysics Technology program. The HiCAT testbed was developed…

‹ Prev 1 3 4 5 6 7 10 Next ›