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.

Detectors and cooling technology for direct spectroscopic biosignature characterization

“…19 More recently, they have been used at the telescope to provide diffractionlimited imagine via the "lucky imaging" technique. 20 Although HgCdTe APD arrays have been made by DRS, Raytheon, and Teledyne; those made by Selex in the UK are the focus of most attention in astronomy now.…”

“…A group at the University of Hawaii has been evaluationg Selex SAPHIRA for applications including low background astronomy. 20 With appropriately optimized process, the HgCdTe itself is potentially capable of the same QE performance as the JWST arrays. 6 Moreover, because gain is built into the pixels before the first amplifier, they promise photon counting and potentially even single photon detection if "dark current" can be reduced to acceptable levels.…”

ATLAST detector needs for direct spectroscopic biosignature characterization in the visible and near-IR

“…16 More recently, they have been used at the telescope to provide diffraction-limited imaging via the "lucky imaging" technique. 17 Although HgCdTe APD arrays have been made by DRS, Raytheon, and Teledyne; those made by Selex are the focus of most attention in astronomy now.…”

High-Speed Imaging and Wavefront Sensing With an Infrared Avalanche Photodiode Array

“…Prior laboratory testing of the detector in a dark cryostat at this bias voltage (Atkinson et al 2014) showed an effective rms read noise of 0.73 e − after avalanche gain for a single correlated double sampling (CDS) read and 72 e − s −1 of dark current. When deployed on sky, we measured the total amount of noise to be 2.52 ± 0.18 e − per CDS read.…”

“…In this experiment, we used an engineering-grade non-antireflection-coated Mark 3 Selex ES Infrared SAPHIRA detector (Atkinson et al 2014;Finger et al 2014). The detector was a metal organic phase epitaxy (MOVPE) HgCdTe APD array comprising 24 μm square pixels in a 320 × 256 format.…”