AO4ELT5 Proceedings
On-sky performance demonstration of the near infrared SAPHIRA e-APD array and new developments of e-APD technology
Finger, Gert (European Southern Observatory), Baker, Ian (Leonardo), Alvarez, Domingo (European Southern Observatory), Dupuy, Christophe (European Southern Observatory), Ives, Derek (European Southern Observatory), Mehrgan, Leander (European Southern Observatory), Meyer, Manfred (European Southern Observatory), Stegmeier, Joerg (European Southern Observatory), Weller, Harald (Leonardo)
A total of five near infrared SAPHIRA 320x256 pixel e-APD arrays have been deployed in the wavefront sensors and in the fringe tracker of the VLTI instrument GRAVITY. First results obtained by coherently combining the light of the four 8 meter telescopes of the VLTI have demonstrated diffraction limited performance with the CIAO adaptive optics system and a sensitivity improvement by a factor of 10 to 100 for interferometric observations. New APD developments since GRAVITY include the extension of the spectral sensitivity to the wavelength range from 0.8 um to 2.5 um. A larger format of 512x512 pixels is in development. At moderate APD gains the eAPD arrays have dark currents of <2E-3 e/s/pixel and outperform conventional state-of-the-art large format NIR science focal planes for integration times as long as 100s.
DOI: 10.26698/AO4ELT5.0041- Proceeding PDF
