Abstract | Wavefront sensors (WFS) are key components for Adaptive Optics (AO) systems to deliver diffraction-limited images with current ground-based telescopes and future Extremely Large Telescopes. A new WFS concept, the Flattened Pyramid WFS (FPWFS), seems very promising in theory [1], with performances exceeding the “conventional” Pyramid WFS [2, 3], which was already superior to the Shack-Hartmann WFS. This new WFS has never been tested in a lab because the fabrication of a glass pyramid with a very shallow apex angle is technologically challenging. However, there is a simple way to mimic a “Flattened” Pyramid WFS with a regular double-pyramid, originally designed for NFIRAOS [4]. A lens can be arranged in order to overlap the four pupils on the detector. This paper describes the optical setup of the Flattened Pyramid WFS test bed built in the NRC-HAA AO lab, as well as the algorithms used to reconstruct the wavefront, and compares its performance with a conventional Pyramid WFS. |
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