Fast focal plane wavefront sensing on ground-based telescopes

TL;DR

This paper introduces FAST, a rapid wavefront sensing method using the self-coherent camera for ground-based telescopes, aiming to improve exoplanet imaging by correcting aberrations in real-time.

Contribution

It develops a framework for implementing FAST with optimized coronagraphs and control algorithms, enhancing wavefront correction capabilities for exoplanet observation.

Findings

Exploration of manufacturing limitations of the SCC FPM.

Development of a framework for FAST deformable mirror control.

Potential to reach contrast levels near photon noise limit.

Abstract

Exoplanet detection and characterization through extreme adaptive optics (ExAO) is a key science goal of future extremely large telescopes. This achievement, however, will be limited in sensitivity by both quasi-static wavefront errors and residual AO-corrected atmospheric wavefront errors. A solution to both of these problems is to use the science camera of an ExAO system as a wavefront sensor to perform a fast measurement and correction method to remove these aberrations as soon as they are detected. We have developed the framework for one such method, using the self-coherent camera (SCC), to be applied to ground-based telescopes, called Fast Atmospheric SCC Technique (FAST; Gerard et al., submitted). Our FAST solution requires an optimally designed coronagraph (the SCC FPM) and post-processing algorithm and is in principle able to reach a "raw" contrast of a few times the photon noise limit, continually improving with integration time. In this paper, we present new ongoing work in exploring the manufacturing limitations of the SCC FPM as well as a general framework to implement and optimize a FAST deformable mirror control loop.