Observatory deployment and characterization of SAPHIRA HgCdTe APD arrays

Abstract

We report the performance of Selex ES' SAPHIRA APD arrays from both laboratory characterization and telescope deployment.The arrays are produced using the MOVPE production method, allowing for solid state engineering and thus produce superior performance to similar liquid phase epitaxy efforts.With an avalanche gain slightly over 50 and read noise of ∼9e -, the detectors are easily capable of single-frame sub-electron read noise, and the 32 output readout and flexible windowing allow an excellent readout speed.Gain-corrected dark current/glow is found to be 10-20 e -/s at low bias, and drops below basline at high avalanche gains.The detectors were also tested on-sky at both IRTF on Maunakea and the 1.5-m telescope at Palomar Observatory, demonstrating that the SAPHIRA is an ideal device for both tip-tilt NGS guiding and infrared lucky imaging, in the latter providing diffraction-limited resolution for the 3-meter IRTF without the benefit of adaptive optics correction.