An illuminator for irradiating targets to change their properties
comprises at least one LED having spectral properties that are capable of
interacting with a target to effect changes in its properties, a
non-imaging concentrator for collecting radiation from the LED and
emitting it as a spatially and spectrally uniform beam over a
predetermined solid angle, and a light guide coupled to the exit aperture
of the non-imaging concentrator to direct radiation to the target.