Infrared vector-apodizing phase plates: prototyping for ELT/METIS/MICADO

The vector-Apodizing Phase Plate (vAPP) coronagraph is a single-element pupil-plane coronagraph that achromatically modifies phase to null star light in regions close to the star. The vAPP phase design can be optimized for any pupil shape to have small inner working angles and has been installed on multiple 8-m class telescopes. In this paper, we describe the manufacturing and performance testing of ELT/METIS and ELT/MICADO prototype vAPPs. We show the new vAPP designs and describe the manufacturing by Colorlink Japan, ltd. First, we demonstrate the performance of scaled vAPP prototypes manufactured in Nov 2023. We review the development and manufacturing of the liquid-crystal film, the alignment and performance of the chromium amplitude mask, and component level tests.