THE OPTICS OF THE OWL 100-M ADAPTIVE TELESCOPE

Abstract

The optical design of the OWL 100-m class visible and near-infrared telescope, with integrated adaptive optics, departs substantially from classical two-mirror solutions. We propose using spherical shapes for the primary and secondary mirrors due to manufacturing, performance and cost constraints. The optical prescription must balance conflicting constraints such as the design of the telescope structure, the constraints set by adaptive tomography correction, and the feasibility of the corrective optics which compensates for the spherical and field aberrations of the primary-secondary mirrors. The number of mirrors, larger than in classical 2-mirror designs, implies additional variables. Within the limits set by the feasibility of optical testing of the aspheric surfaces, we present two optical designs for the telescope and derive high level requirements on active and adaptive control. Keywords OWL, Extremely Large Telescope, Optical Design, active optics, adaptive optics, segmented optics, optical fabrication, optical testing. 1.