Analyzing Misalignment Tolerances for Implicit Electric Field Conjugation

TL;DR

This paper evaluates the robustness of implicit Electric Field Conjugation (iEFC) wavefront control against misalignments in optical systems, using simulations based on the MagAO-X instrument to inform tolerancing requirements for future telescopes.

Contribution

It provides a detailed analysis of how pupil and focal plane misalignments affect iEFC performance, establishing alignment tolerance guidelines for ground- and space-based high contrast imaging systems.

Findings

iEFC performance degrades with pupil and focal plane misalignments.

Simulations demonstrate specific alignment tolerances for effective iEFC operation.

Results inform design and calibration procedures for future high-contrast imaging instruments.

Abstract

High contrast imaging of extrasolar planets and circumstellar disks requires extreme wavefront stability. Such stability can be achieved with active wavefront control (WFC). The next generation of ground- and space-based telescopes will require a robust form of WFC in order to image planets at small inner working angles and extreme flux ratios with respect to the host star. WFC algorithms such as implicit Electric Field Conjugation (iEFC) reduce stellar leakage by minimizing the electric field within a given region of an image, creating a dark hole. iEFC utilizes an empirical approach to sense and remove speckles in the focal plane. While iEFC is empirically calibrated and can handle optical model errors, there are still model assumptions made during the calibration. The performance of iEFC will degrade if the system changes due to slow, optomechanical drifts. In this work, we assess the iEFC performance impacts of pupil misalignments on the deformable mirror and focal plane misalignments on the detector. We base our analysis on the MagAO-X instrument, an extreme AO system installed on the Magellan-Clay telescope, to develop iEFC misalignment tolerancing requirements for both ground- and space-based missions. We present end-to-end physical optics simulations of the MagAO-X instrument, demonstrating iEFC alignment tolerance.