Abstract: An apparatus for curing a coating composition disposed on a glass optical fiber. The apparatus includes a reflector, the reflector having an interior surface delineating a boundary of a cavity, the interior surface including a plurality of portions, each of the portions extending along a different curved contour. Furthermore, each of the plurality of portions is configured to reflect curing light so that the reflected curing light is concentrated to a curing zone within the cavity such that all the reflected curing light within the curing zone has an intensity of about 60% or greater relative to a maximum intensity of the reflected curing light. A fiber location for the glass optical fiber is located within the curing zone. Additionally, the plurality of portions includes at least a first portion and a second portion, the first portion having a different degree of curvature than the second portion.