Pupil stabilization for SPHERE's extreme AO and high performance coronagraph system

TL;DR

This paper introduces a novel pupil motion sensor for extreme adaptive optics systems, validated through laboratory experiments, to enhance high contrast imaging by stabilizing the pupil and reducing aberrations.

Contribution

A new pupil stabilization concept using wave-front sensor flux data and a focal plane mirror, validated experimentally for high contrast astronomical imaging.

Findings

Successful laboratory validation of the pupil stabilization concept.

Demonstrated reduction of quasi-static aberrations in high contrast imaging.

Potential application for future planet finder instruments.

Abstract

We propose a new concept of pupil motion sensor for astronomical adaptive optics systems and present experimental results obtained during the first laboratory validation of this concept. Pupil motion is an important issue in the case of extreme adaptive optics, high contrast systems, such as the proposed Planet Finder instruments for the ESO and Gemini 8-meter telescopes. Such high contrast imaging instruments will definitively require pupil stabilization to minimize the effect of quasi-static aberrations. The concept for pupil stabilization we propose uses the flux information from the AO system wave-front sensor to drive in closed loop a pupil tip-tilt mirror located in a focal plane. A laboratory experiment validates this concept and demonstrates its interest for high contrast imaging instrument.