InfraRed On-Detector Guide-Windows in the era of Extremely Large Telescopes

TL;DR

This paper discusses the development and testing of On-Detector Guide Windows (ODGWs) in infrared detectors for future Extremely Large Telescopes, enabling improved wavefront sensing and detector management within the science focal plane.

Contribution

It introduces a prototype ODGW system using a Teledyne HAWAII-2RG detector and describes its implementation and observed artifacts, advancing adaptive optics capabilities for ELTs.

Findings

Prototype ODGW system demonstrated with infrared detector.

Identified artifacts in science images due to ODGW operation.

Potential for improved wavefront correction and detector control.

Abstract

Future Extremely Large Telescopes (ELTs) will require advances in Adaptive Optics (AO) systems to fully realize their potential. In addition to separate, dedicated wavefront sensors, it is recognized that wavefront sensing within the science focal plane itself will also be needed for many new instruments. One approach is to use On-Detector Guide Windows (ODGWs), whereby a small sub-window of a science detector is read-out continuously (~10s-100s of Hz) in parallel with slower reads of the full chip (>10 s). Guide star centroids from these windows can be used to correct for vibrations and flexure. Another potential use for these windows is to perform localized resets at high cadence to prevent saturation and to minimize persistence from bright sources. We have prototyped an ODGW system using a 5-um cutoff Teledyne HAWAII-2RG infrared detector, and the new Astronomical Research Cameras Gen-4 controller. We describe our implementation of an ODGW mode, and science image artifacts that were observed.