The Shack-Hartmann Phasing Sensor (SHAPS) has been integrated in the Active Phasing Experiment (APE) at ESO.
It is currently under test in the laboratory. The tests on sky are foreseen for the end of 2008, when APE will be mounted
at the Nasmyth focus of one of the VLT unit telescopes. SHAPS is based on the Shack-Hartmann principle: the lenslet
array is located in a plane which is optically conjugated to the Active Segmented Mirror (ASM) of APE and is composed
of two types of microlenses, circular and cylindrical, which give information about the wavefront slope and the piston
steps, respectively. This proceeding contains a description of SHAPS and of the algorithms implemented for the
wavefront reconstruction and for the phasing. The preliminary results obtained during the laboratory tests are discussed
and compared with the theoretical predictions. The performances of SHAPS at the VLT and at the European Extremely
Large Telescope (E-ELT) are estimated.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.