Optimized focal and pupil plane masks for vortex coronagraphs on telescopes with obstructed apertures

TL;DR

This paper introduces optimized pupil and focal plane masks for vortex coronagraphs tailored for telescopes with obstructed apertures, enhancing starlight suppression and exoplanet detection capabilities.

Contribution

It develops analytical and numerical methods for designing complex masks that improve vortex coronagraph performance on obstructed or segmented telescopes.

Findings

Improved starlight suppression and contrast.

Effective mitigation of diffraction from aperture obstructions.

Enhanced off-axis image quality for exoplanet detection.

Abstract

We present methods for optimizing pupil and focal plane optical elements that improve the performance of vortex coronagraphs on telescopes with obstructed or segmented apertures. Phase-only and complex masks are designed for the entrance pupil, focal plane, and the plane of the Lyot stop. Optimal masks are obtained using both analytical and numerical methods. The latter makes use of an iterative error reduction algorithm to calculate "correcting" optics that mitigate unwanted diffraction from aperture obstructions. We analyze the achieved performance in terms of starlight suppression, contrast, off-axis image quality, and chromatic dependence. Manufacturing considerations and sensitivity to aberrations are also discussed. This work provides a path to joint optimization of multiple coronagraph planes to maximize sensitivity to exoplanets and other faint companions.