Refractive optical element having a convex helical surface for athermalizing an infrared imaging system

摘要

Refractive optical element for athermalizing an infrared imaging system, said element being detachably mounted to the latter and having a circular base and a convex surface with an helical profile, the radial jog of which ascending helically from the lower edge (1) to the upper edge (2) of the jog.