Short for Cassegrain reflector.

plural of Cassegrain

plural of Cassegrain reflector

A combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas, the main characteristic being that the optical path folds back onto itself, relative to the optical system's primary mirror entrance aperture.

Of or relating to Laurent Cassegrain (ca. 1629—1693), Catholic priest remembered as the probable inventor of the Cassegrain reflector, a folded two-mirror reflecting telescope.