Glow reduction of ultra-low noise LmAPDs: towards photon counting infrared arrays

TL;DR

This paper reports on the development and testing of ultra-low noise infrared detectors, specifically LmAPDs, achieving extremely low glow and dark current levels, enabling single-photon detection for advanced astronomical observations.

Contribution

The paper introduces recent improvements in LmAPDs that significantly reduce glow and dark current, advancing the potential for photon counting in infrared astronomy.

Findings

ROIC glow reduced to 0.01 e-/pixel/frame

Dark current essentially zero (< 0.1 e-/pixel/kilosecond)

Devices capable of single-photon detection at high gain

Abstract

Spectroscopy and direct-imaging of ultra-faint targets such as Earth-like exoplanets and high redshift galaxies are among the primary goals of upcoming large scale astronomy projects like the Habitable World Observatory (HWO). Such objectives pose extreme instrumental challenges, in particular on detectors where dark currents lower than 1 e-/pixel/kilosecond and read noise less than 1 e-/pixel/frame will have to be achieved on large format arrays. Some technologies meet these requirements at optical wavelengths, but none do in the infrared. With this goal in mind, the University of Hawaii has partnered with Leonardo to develop linear-mode avalanche photodiodes (LmAPDs). In this paper, we report recent tests performed on LmAPDs, where we measure a ROIC glow of approximately 0.01 e-/pixel/frame, without which the intrinsic dark current is essentally zero (< 0.1 e- /pixel/kilosecond). We show that at high gain, these devices are capable of detecting single photons