Characterizing the performance of two C-RED ONE cameras for implementation in RISTRETTO and SAXO+ projects

• Main Authors: Shinde, Muskan, Baron, Jana Anouk, Blind, Nicolas, Hagelberg, Janis, Lovis, Christophe, Wildi, François, Ségransan, Damien
• Format: Journal Article
• Language: English
• Published: 06-09-2024
• Subjects: Physics - Instrumentation and Methods for Astrophysics
• DOI: 10.48550/arxiv.2409.04247

Proc. SPIE 13097, Adaptive Optics Systems IX, 1309744 (29 August
2024) In the near-infrared wavelength regime, atmospheric turbulence fluctuates at
a scale of a few milliseconds, and its precise control requires the use of
extreme adaptive optics (XAO) systems equipped with fast and sensitive
detectors operating at kHz speeds. The C-RED One cameras developed by First
Light Imaging (FLI), based on SAPHIRA detectors made of HgCdTe e-APD array
sensitive to 0.8-2.5 $\mu$m light, featuring a 320x256 pixels with 24 $\mu$m
pitch, offering sub-electron readout noise and the ability to read subarrays,
at frame-rates of up to few 10-kHz, are state-of-the-art for XAO wavefront
sensing. The Observatory of Geneva purchased two C-RED One cameras identified
as necessary for RISTRETTO (a proposed high-contrast high-resolution
spectrograph for the VLT) and SAXO+ (an upgrade of the VLT/SPHERE XAO system)
projects. We present a comprehensive characterization and comparative analysis
of both the cameras. We present test results examining key noise contributors,
including readout noise, detector bias, etc. And we also study their temporal
variability. Additionally, we assess the conversion gain and the avalanche gain
calibration of the detector. We also study the evolution some of these
parameters over time.