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Directly imaging and characterizing Earth-like exoplanets is a tremendously difficult instrumental challenge. Present coronagraphic systems have yet to achieve the required $10^{-10}$ broadband contrast in a laboratory environment, but…

Instrumentation and Methods for Astrophysics · Physics 2019-07-10 Carl T. Coker , Stuart B. Shaklan , A J E. Riggs , Garreth Ruane

Phase masks coronagraphs can be seen as linear systems that spatially redistribute, in the pupil plane, the energy collected by the telescope. Most of the on-axis light must ideally be rejected outside the aperture to be blocked with a Lyot…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Alexis Carlotti

Vortex coronagraphs have been shown to be a promising avenue for high-contrast imaging in the close-in environment of stars at thermal infrared (IR) wavelengths. They are included in the baseline design of METIS. To ensure good performance…

Recent adaptive optics systems in astronomy achieve high-angular resolution. With the extreme stability of the images, detection at very low fluxes can be reached using a coronograph at the diffraction limit of the telescopes. This paper is…

Astrophysics · Physics 2007-05-23 Fabien Malbet

Imaging exo-Earths is an exciting but challenging task because of the 10^-10 contrast ratio between these planets and their host star at separations narrower than 100 mas. Large segmented aperture space telescopes enable the sensitivity…

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

We present designs for fully achromatic vector Apodizing Phase Plate (vAPP) coronagraphs, that implement low polarization leakage solutions and achromatic beam-splitting, enabling observations in broadband filters. The vAPP is a pupil plane…

Instrumentation and Methods for Astrophysics · Physics 2018-11-27 Steven P. Bos , David S. Doelman , Jos de Boer , Emiel H. Por , Barnaby Norris , Michael J. Escuti , Frans Snik

State-of-the-art coronagraphs employed on extreme adaptive optics enabled instruments, are constantly improving the contrast detection limit for companions at ever closer separations to the host star. In order to constrain their properties…

Instrumentation and Methods for Astrophysics · Physics 2015-11-11 Nemanja Jovanovic , Olivier Guyon , Frantz Martinache , Prashant Pathak , Janis Hagelberg , Tomoyuki Kudo

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…

Ptychographic Coherent Diffractive Imaging enables diffraction-limited imaging of nanoscale structures at extreme ultraviolet and x-ray wavelengths, where high-quality image-forming optics are not available. However, its reliance on a set…

Using an l = 1 blazed fork-hologram at the focal plane of the Asiago 122 cm telescope, we obtained optical vortices from the stellar system Rasalgethi (alpha Herculis) and from the single star Arcturus (alpha Bootis). We have analyzed the…

Optics · Physics 2010-07-21 F. Tamburini , G. Anzolin , G. Umbriaco , A. Bianchini , C. Barbieri

Stellar coronagraph performance is highly sensitive to optical aberrations. In order to effectively suppress starlight for exoplanet imaging applications, low-order wavefront aberrations entering a coronagraph such as tip-tilt, defocus and…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Hari Subedi , Neil T. Zimmerman , N. Jeremy Kasdin , Kathleen Cavanagh , A J Eldorado Riggs

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…

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 present here new experimental results on high contrast imaging of 10^{-7} at 4.5Lambda/D (Lambda = 0.820 microns) by combining a circular focal plane mask (coronagraph) of 2.5Lambda/D diameter and a multi-Gaussian pupil plane mask. Both…

Astrophysics · Physics 2009-11-10 Abhijit Chakraborty , Laird A. Thompson , Mike Rogosky

Deformable mirrors (DMs) are a critical technology to enable coronagraphic direct imaging of exoplanets with current and planned ground - and space-based telescopes as well as future mission concepts that aim to image exoplanet types…

Instrumentation and Methods for Astrophysics · Physics 2020-11-05 Eduardo Bendek , Garreth Ruane , Camilo Mejia Prada , Christopher B. Mendillo , A. J. Eldorado Riggs , Eugene Serabyn

We describe a coronagraphic optic for use with CONICA at the VLT that provides suppression of diffraction from 1.8 to 7 lambda/D at 4.05 microns, an optimal wavelength for direct imaging of cool extrasolar planets. The optic is designed to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Matthew A. Kenworthy , Sascha P. Quanz , Michael R. Meyer , Markus E. Kasper , Rainer Lenzen , Johanan L. Codona , Julien H. V. Girard , Philip M. Hinz

To reach and maintain high contrast levels, coronagraph instruments will require a combination of low-order and high-order wavefront control techniques to correct for dynamic wavefront error. Efficient low-order wavefront sensing and…

Future space telescopes with coronagraph instruments will use a wavefront sensor (WFS) to measure and correct for phase errors and stabilize the stellar intensity in high-contrast images. The HabEx and LUVOIR mission concepts baseline a…

Segmented telescopes are a possibility to enable large-aperture space telescopes for the direct imaging and spectroscopy of habitable worlds. However, the complexity of their aperture geometry, due to the central obstruction, support…

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