Exoplanet imaging with a phase-induced amplitude apodization coronagraph. III. Diffraction effects and coronagraph design

Eugene A. Pluzhnik, Olivier Guyon, Stephen T. Ridgway, Frantz Martinache, Robert A. Woodruff, Celia Blain, Raphael Galicher

Research output: Contribution to journalArticle

42 Scopus citations

Abstract

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) unfortunately requires most of the light gathered by the telescope to be absorbed, resulting in poor throughput and low angular resolution. Phase-induced amplitude apodization (PIAA) of the telescope pupil combines the advantages of classical pupil apodization (particularly low sensitivity to low-order aberrations) with full throughput, no loss of angular resolution and little chromaticity, which makes it, theoretically, an extremely attractive coronagraph for direct imaging of ETPs. The two most challenging aspects of this technique are (1) the difficulty of polishing the required optics shapes and (2) diffraction propagation effects, which, because of their chromaticity, can decrease the spectral bandwidth of the coronagraph. We show that a properly designed hybrid system combining classical apodization with the PIAA technique can solve both problems simultaneously. For such a system, the optics shapes can be well within today's optics manufacturing capabilities, and the 10 -10 PSF contrast at ≈ 1.5Λ/D required for efficient imaging of ETPs can be maintained over the whole visible spectrum. This updated design of the PIAA coronagraph maintains the high performance of the earlier design, since only a small part of the light is lost in the classical apodizer(s).

Original languageEnglish (US)
Pages (from-to)1246-1257
Number of pages12
JournalAstrophysical Journal
Volume644
Issue number2 II
DOIs
Publication statusPublished - Jun 10 2006
Externally publishedYes

    Fingerprint

Keywords

  • High angular resolution
  • Instrumentation

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Pluzhnik, E. A., Guyon, O., Ridgway, S. T., Martinache, F., Woodruff, R. A., Blain, C., & Galicher, R. (2006). Exoplanet imaging with a phase-induced amplitude apodization coronagraph. III. Diffraction effects and coronagraph design. Astrophysical Journal, 644(2 II), 1246-1257. https://doi.org/10.1086/503829