SLM-based Digital Adaptive Coronagraphy: Current Status and Capabilities

TL;DR

This paper reviews the current status and capabilities of digital adaptive coronagraphy using liquid-crystal SLMs, highlighting recent laboratory performance, potential improvements, and unique functionalities like wavefront sensing and nulling of multiple stars.

Contribution

It introduces a new framework called digital adaptive coronagraphy with liquid-crystal SLMs, demonstrating its current performance and potential for advanced high-contrast imaging applications.

Findings

Laboratory contrast performance achieved with monochromatic visible light.

Potential pathways identified for improving SLM coronagraphic nulling.

Demonstrated capabilities include wavefront sensing, adaptive phase masks, and nulling of multiple star systems.

Abstract

Active coronagraphy is deemed to play a key role for the next generation of high-contrast instruments, notably in order to deal with large segmented mirrors that might exhibit time-dependent pupil merit function, caused by missing or defective segments. To this purpose, we recently introduced a new technological framework called digital adaptive coronagraphy (DAC), making use of liquid-crystal spatial light modulators (SLMs) display panels operating as active focal-plane phase mask coronagraphs. Here, we first review the latest contrast performance, measured in laboratory conditions with monochromatic visible light, and describe a few potential pathways to improve SLM coronagraphic nulling in the future. We then unveil a few unique capabilities of SLM-based DAC that were recently, or are currently in the process of being, demonstrated in our laboratory, including NCPA wavefront sensing, aperture-matched adaptive phase masks, coronagraphic nulling of multiple star systems, and coherent differential imaging (CDI).