Abstract: A system, designed to cure an ultraviolet sensitive coating on a substrate that is moving in a direction transverse to the radiation emitted from the system, which includes a plurality of arrays of short-arc ultraviolet lamps, each array located in a suitable housing. The arc of each lamp in a given array is located at the focus of an associated paraboloidal reflector mounted within the housing so that at least half of the ultraviolet radiation emanating from the arc is reflected by the paraboloidal reflector to produce a collimated beam of ultraviolet radiation directed toward a concave spherical reflector whose center is located axially with the paraboloidal reflector. As measured between the two reflectors, the axis of the spherical reflector normally forms a (45.degree.) angle with respect to the axis of the paraboloidal reflector to reflect the collimated beam toward the substrate. Because of the concave surface of the spherical reflector, the radiant energy is focused to a small area on the substrate.