Three years of harvest with the vector vortex coronagraph in the thermal infrared

TL;DR

This paper reviews three years of development, deployment, and scientific results of vortex coronagraphs in the thermal infrared, highlighting their performance and future potential in astronomical observations.

Contribution

It presents the development, on-sky performance, and scientific outcomes of AGPM vortex phase masks used in thermal infrared astronomy over three years.

Findings

Successful deployment on multiple telescopes since 2012

Enhanced imaging capabilities in the thermal infrared range

Insights into lessons learned and future improvements

Abstract

For several years, we have been developing vortex phase masks based on sub-wavelength gratings, known as Annular Groove Phase Masks. Etched onto diamond substrates, these AGPMs are currently designed to be used in the thermal infrared (ranging from 3 to 13 {\mu}m). Our AGPMs were first installed on VLT/NACO and VLT/VISIR in 2012, followed by LBT/LMIRCam in 2013 and Keck/NIRC2 in 2015. In this paper, we review the development, commissioning, on-sky performance, and early scientific results of these new coronagraphic modes and report on the lessons learned. We conclude with perspectives for future developments and applications.