A Pyramid WFS For LBT AGW Unit S. Esposito, A. Riccardi, D. Ferruzzi, A. Tozzi, M. Accardo, M. Carbillet, C. Verinaud, L. Fini, A. Puglisi, P. Salinari
Scientific Aim Answering a first fundamental question: “ Whould you let those guys.... [J. Hill, , 16 October 2001]....project your AO system ? ”
A Moveable WFS for the AGW unit Reduce the number of optical elements Minimize NCP aberrations Minimize system flexure Easy assembly and testing of the WFS unit
The Optical Design I
The Optical Design II Telecentric lens Refocusing lens and folding mirror Pyramid unit 2 Folding mirrors ADC & Tip-Tilt mirror Reimaging lens F15 beam from LBT 117 mm 294 mm
Spot quality on the pyramid I ON Axis Spot1’ OFF Axis Spot Zenith pointing
Spot quality on the pyramid II ON Axis Spot1’ OFF Axis Spot 70 deg from Zenith pointing
The Pyramid design I Vertex 30°, SK10 Vertex 28.2°, SSK2 FOV +/- 1 arcsec Energy loss on edges < 10 % Chromatism 3.5 m (0.6 – 1.0 m)
The Pyramid design II
The board assembly
The APD-based TIP-TILT system
Work in progress…… Optical design & Pyramid design optimization Optical & echanical tolerances echanical design System performance simulations other