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

Area of Science:

• Astronomy and Astrophysics
• Optical Engineering

Background:

• Pupil motion is a critical challenge in extreme adaptive optics (AO) and high-contrast imaging systems.
• Quasi-static aberrations significantly impact the performance of instruments like the proposed Planet Finder for ESO and Gemini telescopes.
• Stabilizing the pupil is essential for achieving high contrast and minimizing unwanted optical effects.

Purpose of the Study:

• To introduce and validate a new concept for a pupil motion sensor.
• To demonstrate the effectiveness of this sensor in stabilizing the pupil for astronomical applications.
• To highlight the sensor's utility for high-contrast imaging instruments.

Main Methods:

• The proposed concept utilizes flux information from the AO system's wavefront sensor.
• A closed-loop system drives a pupil tip-tilt mirror located in the focal plane.
• Laboratory experiments were conducted for initial validation.

Main Results:

• The laboratory experiment successfully validated the proposed pupil motion sensor concept.
• The results demonstrate the sensor's capability to stabilize pupil motion.
• The study confirms the sensor's relevance and potential benefits for high-contrast imaging.

Conclusions:

• The developed pupil motion sensor concept is effective for stabilizing pupils in astronomical adaptive optics systems.
• This technology is particularly beneficial for high-contrast imaging instruments requiring minimal aberrations.
• The experimental validation supports the implementation of this sensor in future advanced astronomical instruments.