EDP Sciences
Free Access
Issue
A&A
Volume 403, Number 1, May III 2003
Page(s) 369 - 381
Section Physical and chemical processes
DOI https://doi.org/10.1051/0004-6361:20030278


A&A 403, 369-381 (2003)
DOI: 10.1051/0004-6361:20030278

Achromatic dual-zone phase mask stellar coronagraph

R. Soummer1, K. Dohlen2 and C. Aime1

1  Laboratoire Universitaire d'Astrophysique de Nice - UMR 6525, Université de Nice Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2, France
    e-mail: Claude.Aime@unice.fr
2  Laboratoire d'Astrophysique de Marseille, 2 place Leverrier, 13248 Marseille, Cedex 4, France
    e-mail: Kjetil.Dohlen@oamp.fr

(Received 31 October 2002 / Accepted 14 February 2003)

Abstract
This paper presents a generalization of the Roddier & Roddier Phase Mask coronagraph for polychromatic observations. It is shown that using a dual-zone phase mask, combined with complex apodization, both phase and size chromatism can be compensated simultaneously to produce high extinction of a point source over large bandwidths, for example the entire K band with a residual integrated starlight of $3.2\times
10^{-4}$ and a star intensity level of  10-6 at an angular separation of  $3\lambda/D$. Other advantages of the proposed technique include the compatibility with centrally obscured telescopes, absence of blind axes and no symmetrization of the images.


Key words: instrumentation: high angular resolution -- techniques: high angular resolution -- stars: planetary systems

Offprint request: R. Soummer, Remi.Soummer@unice.fr




© ESO 2003

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.