Adaptive optics for high-contrast imaging: Pyramid sensor versus spatially filtered Shack-Hartmann sensor

Abstract

A comparison between pyramid-based and spatially filtered Shack-Hartmann-based highorder adaptive optics (AO) is presented in the framework of 8-m-class and extremely large telescopes (ELTs).We first show, with end-to-end simulations of an 8-mAOassisted telescope, how each sensor deals with the aliasing error, which may be the dominant error source at high flux. Then, focusing on photon noise error propagation, we study the field dependence of the sensitivity gain provided by the pyramid sensor with respect to the Shack-Hartmann sensor. From this analysis, we investigate, with an analytical model, visible correction on ELTs for detection of Earth-like exoplanets. © 2005 RAS.