Optimal Dark Hole Generation via Two Deformable Mirrors with Stroke Minimization

TL;DR

This paper presents an algorithm for high-contrast imaging using two deformable mirrors to generate symmetric dark holes with minimal stroke, advancing space-based exoplanet observation capabilities.

Contribution

It introduces a novel stroke minimization algorithm for dual deformable mirrors to effectively create symmetric dark holes in high-contrast imaging.

Findings

Successful demonstration of symmetric dark hole in monochromatic light

Effective correction of amplitude aberrations and wavefront flattening

Reduced stroke requirements for deformable mirrors

Abstract

The past decade has seen a significant growth in research targeted at space based observatories for imaging exo-solar planets. The challenge is in designing an imaging system for high-contrast. Even with a perfect coronagraph that modifies the point spread function to achieve high-contrast, wavefront sensing and control is needed to correct the errors in the optics and generate a "dark hole". The high-contrast imaging laboratory at Princeton University is equipped with two Boston Micromachines Kilo-DMs. We review here an algorithm designed to achieve high-contrast on both sides of the image plane while minimizing the stroke necessary from each deformable mirror (DM). This algorithm uses the first DM to correct for amplitude aberrations and the second DM to create a flat wavefront in the pupil plane. We then show the first results obtained at Princeton with this correction algorithm, and we demonstrate a symmetric dark hole in monochromatic light.