Implementation of a broadband focal plane estimator for high-contrast dark zones

TL;DR

This paper presents a broadband focal plane wavefront estimation algorithm designed for high-contrast imaging, reducing complexity and overheads by using only broadband images, with implementation details and performance comparison to narrowband methods.

Contribution

The paper introduces a detailed implementation of a broadband focal plane estimator and demonstrates its application to a testbed, comparing its performance to traditional narrowband techniques.

Findings

Broadband approach reduces observational overheads.

Algorithm successfully estimates electric field from broadband images.

Performance comparison shows advantages over narrowband methods.

Abstract

The characterization of exoplanet atmospheres using direct imaging spectroscopy requires high-contrast over a wide wavelength range. We study a recently proposed focal plane wavefront estimation algorithm that exclusively uses broadband images to estimate the electric field. This approach therefore reduces the complexity and observational overheads compared to traditional single wavelength approaches. The electric field is estimated as an incoherent sum of monochromatic intensities with the pair-wise probing technique. This paper covers the detailed implementation of the algorithm and an application to the High-contrast Imager for Complex Aperture Telescopes (HiCAT) testbed with the goal to compare the performance between the broadband and traditional narrowband filter approaches.