AO3000 at Subaru: Combining for the first time a NIR WFS using First Light's C-RED ONE and ALPAO's 64x64 DM

TL;DR

This paper describes the first integration of a near-infrared wavefront sensor using First Light's C-RED ONE camera with ALPAO's 64x64 deformable mirror on Subaru's AO3000 system, enhancing high-contrast imaging capabilities.

Contribution

It introduces the novel combination of a NIR wavefront sensor with a high-actuator-count deformable mirror and the first on-sky results of this upgraded adaptive optics system.

Findings

Successful integration of C-RED ONE camera with AO3000 system.

First on-sky demonstration of NIR wavefront sensing with high-actuator DM.

Enhanced high-contrast imaging potential for Subaru Telescope.

Abstract

After 16 years of on-sky operation, Subaru Telescope's facility adaptive optics AO188 is getting several major upgrades to become the extreme-AO AO3000 (3000 actuators in the pupil compared to 188 previously). AO3000 will provide high-Strehl images for several instruments from visible to mid-infrared, notably the Infrared Camera and Spectrograph (IRCS), and the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO). For this upgrade, the original 188-element deformable mirror (DM) will be replaced with ALPAO's $64\times64$ DM. The visible wavefront sensor will also be upgraded at a later date, but in the meantime we are adding a near-infrared Wavefront Sensor (NIR WFS), using either a double roof prism pyramid mode or a focal plane WFS mode. This new wavefront sensor will use for the first time First Light's C-RED ONE camera, allowing for a full control of the $64\times64$ DM at up to 1.6 kHz. One of the challenges is the use of non-destructive reads and a rolling shutter with the modulated pyramid. This upgrade will be particularly exciting for SCExAO, since the extreme-AO loop will focus more on creating high-contrast dark zones instead of correcting large atmospheric residuals. It will be the first time two extreme-AO loops will be combined on the same telescope. Finally, the setup AO3000+SCExAO+IRCS will serve as a perfect demonstrator for the Thirty Meter Telescope's Planetary Systems Imager (TMT-PSI). We will present here the design, integration and testing of AO3000, and show the first on-sky results.