High-contrast Demonstration of an Apodized Vortex Coronagraph

Abstract

High contrast imaging is the primary path to the direct detection and characterization of Earth-like planets around solar-type stars; a cleverly designed internal coronagraph suppresses the light from the star, revealing the elusive circumstellar companions. However, future large-aperture telescopes ($>$4~m in diameter) will likely have segmented primary mirrors, which causes additional diffraction of unwanted stellar light. Here we present the first high contrast laboratory demonstration of an apodized vortex coronagraph (AVC), in which an apodizer is placed upstream of a vortex focal plane mask to improve its performance with a segmented aperture. The gray-scale apodization is numerically optimized to yield a better sensitivity to faint companions assuming an aperture shape similar to the LUVOIR-B concept. Using wavefront sensing and control over a one-sided dark hole, we achieve a raw contrast of $2\times 10^{-8}$ in monochromatic light at 775~nm, and a raw contrast of $4\times 10^{-8}$ in a 10\% bandwidth. These results open the path to a new family of coronagraph designs, optimally suited for next-generation segmented space telescopes.

References in corpus (7)

• Combining high-dispersion spectroscopy (HDS) with high contrast imaging (HCI): Probing rocky planets around our nearest neighbors
• The W. M. Keck Observatory infrared vortex coronagraph and a first image of HIP79124 B
• Apodized phase mask coronagraphs for arbitrary apertures. II. Comprehensive review of solutions for the vortex coronagraph
• Spectroscopic Coronagraphy for Planetary Radial Velocimetry of Exoplanets
• Apodized vortex coronagraph designs for segmented aperture telescopes
• Active correction of aperture discontinuities (ACAD) for space telescope pupils: a parametic analysis
• Space Technology for Directly Imaging and Characterizing Exo-Earths

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