This classic all-reflective configuration has no central obstruction and locates the focal plane to the side of the telescope structure. The parabolic primary segment collimates light reflected by a flat turning mirror from a light source or transilluminated target. These systems are packaged in self-supporting, ruggedized enclosures designed to provide thermal stability. Each mirror is removable for cleaning. Mirrors are made from low expansion Schott Optical Glass Company Zerodur.
Coatings are hard and cleanable.
A mounting plate with bolt circle concentric to the optical axis is provided just ahead of the focal plane. A centering target is aligned to the mounting plate. This target diameter subtends 1 milliradian at the primary mirror and may be inserted into the aperture in the mounting plate to locate the focal plane and optical axis of the telescope. Target wheels, light sources, filters or detectors may be located and aligned relative to the centering target. These high quality, prealigned telescopes are readily adapted to user systems.