Electric Field Conjugation for Ground Based High-Contrast Imaging: Robustness Study and Tests with the Project 1640 Coronagraph

TL;DR

This study evaluates the robustness of the electric field conjugation (EFC) algorithm for ground-based high-contrast imaging, identifying key sensitivities and informing its deployment with the Project 1640 coronagraph.

Contribution

It provides a detailed analysis of EFC's response to optical model deviations, guiding practical implementation for ground-based telescopes.

Findings

EFC is sensitive to unresponsive DM actuators and misalignments.

Vibrations and DM registration are less impactful than expected.

Accurate modeling of core components is crucial for successful EFC corrections.

Abstract

The electric field conjugation (EFC) algorithm has shown promise for removing scattered starlight from high-contrast imaging measurements, both in numerical simulations and laboratory experiments. To prepare for the deployment of EFC using ground-based telescopes we investigate the response of EFC to unaccounted for deviations from an ideal optical model. We explore the linear nature of the algorithm by assessing its response to a range of inaccuracies in the optical model generally present in real systems. We find that the algorithm is particularly sensitive to unresponsive deformable mirror (DM) actuators, misalignment of the Lyot stop, and misalignment of the focal plane mask. Vibrations and DM registration appear to be less of a concern compared to values expected at the telescope. We quantify how accurately one must model these core coronagraph components to ensure successful EFC corrections. We conclude that while the condition of the DM can limit contrast, EFC may still be used to improve the sensitivity of high-contrast imaging observations. Our results have informed the development of a full EFC implementation using the Project 1640 coronagraph at Palomar observatory. While focused on a specific instrument our results are applicable to the many coronagraphs that may be interested in employing EFC.