LIFT on Keck: analysis of performance and first experimental results

摘要

Wavefront sensing in the near infrared has become an attractive option with the advent of new low-noise infrared detectors, such as the SAPHIRA (Selex) and RAPID (CEA/Sofradir) APD arrays. The performance improvements obtained with the H2RG-based Keck I near-infrared tip-tilt sensor is motivating the implementation of a near-infrared low-order sensor for Keck II. The recently proposed focal plane sensor algorithm LIFT could fulfill this role. We show here an analysis of performance, demonstrating that LIFT would provide a significant gain (～ 1 magnitude) over the current tip/tilt sensor at low flux, as well as the first experimental validation of LIFT on Keck with a calibration source.