Speckle Symmetry with High‐Contrast Coronagraphs
Publications of the Astronomical Society of the Pacific2002Vol. 114(792), pp. 132–136
Citations Over TimeTop 10% of 2002 papers
Abstract
We investigate the pattern of residual speckles obtained with high‐contrast coronagraphs and extreme adaptive optics systems. In particular, we provide evidence of symmetry occurring for very small phase defects depending only on the ability of the coronagraph to attenuate the pupil diffraction pattern. In such a case, a centrosymmetrical subtraction of the image significantly increases the signal‐to‐noise ratio. Detection of very faint companions around bright stars may benefit from this characteristic in some particular conditions. Numerical simulations show that speckle symmetry takes place when using a four‐quadrant phase mask coronagraph, for very high Strehl ratio (SR>0.96) and with a filled circular aperture.
Related Papers
- → Apodized Lyot coronagraph for SPHERE/VLT: II. Laboratory tests and performance(2011)100 cited
- → Exoplanet Imaging with a Phase‐induced Amplitude Apodization Coronagraph. III. Diffraction Effects and Coronagraph Design(2006)24 cited
- → Multiple-stage apodized pupil Lyot coronagraph for high-contrast imaging(2004)20 cited
- → A Study of the Possibility of Image Optimization by Apodization Filters in Optical Systems with Residual Aberrations(1979)32 cited
- → Segmented coronagraph design and analysis (SCDA): an initial design study of apodized vortex coronagraphs(2017)2 cited