COMPACT TELESCOPE HAVING A PLURALITY OF FOCAL DISTANCES COMPENSATED BY NON-SPHERICAL OPTICAL COMPONENTS

摘要

The invention relates to an anastigmat telescope with three aspherical mirrors comprising: means (5) for linear displacement of the third mirror (M3) on the optical axis of the telescope (O) so as to vary the focal length of the telescope according to a plurality of focal lengths (fi) between at least a minimum focal length (fmin ) and a maximum focal length (fmax), a plurality of aspheric optical components (CAi) associated respectively with the plurality of focal lengths (fi), the third mirror having a new taper (c'3) determined from an initial taper (c3), the new conicity (c'3) being determined so that the telescope has aberrations that can be compensated by said aspherical components, without the presence of said aspheric components and for the minimum and maximum focal lengths, the position (PCAi) and the shape of the surface (Si) of each aspherical component being determined so as to correct said compensable aberrations of said telescope for the associated focal point (fi) and to optimize the image quality in the first focal plane of the telescope according to a predetermined criterion.