High-speed imaging and wavefront sensing with an infrared avalanche photodiode array

TL;DR

This paper demonstrates the use of an infrared avalanche photodiode array for high-speed imaging and wavefront sensing, improving image quality and enabling new astronomical surveys and adaptive optics applications.

Contribution

It reports on the improved performance of an infrared avalanche photodiode array in high-speed imaging and wavefront sensing, with applications in adaptive optics and astronomical surveys.

Findings

Achieved low read noise of 0.73 e- in lab and 2.52 e- on sky

Improved image quality at visible and infrared wavelengths

Enabled survey of late M-dwarf multiplicity

Abstract

Infrared avalanche photodiode arrays represent a panacea for many branches of astronomy by enabling extremely low-noise, high-speed and even photon-counting measurements at near-infrared wavelengths. We recently demonstrated the use of an early engineering-grade infrared avalanche photodiode array that achieves a correlated double sampling read noise of 0.73 e- in the lab, and a total noise of 2.52 e- on sky, and supports simultaneous high-speed imaging and tip-tilt wavefront sensing with the Robo-AO visible-light laser adaptive optics system at the Palomar Observatory 1.5-m telescope. We report here on the improved image quality achieved simultaneously at visible and infrared wavelengths by using the array as part of an image stabilization control-loop with adaptive-optics sharpened guide stars. We also discuss a newly enabled survey of nearby late M-dwarf multiplicity as well as future uses of this technology in other adaptive optics and high-contrast imaging applications.