A 
high intensity mutli-
wavelength illumination apparatus comprising an array of LEDs each of which has a predetermined spectral output that is emitted over a predetermined 
solid angle, an array of non-imaging concentrators the individual non-imaging concentrators of which are optically coupled in one-to-one correspondence with the LEDs, each non-imaging 
concentrator in the array of non-imaging concentrators operating to collect 
radiation emitted by each of the LEDs and to re-emit substantially all the collected 
radiation as a beam having a diverging 
solid angle smaller than said predetermined 
solid angle over which 
radiation is emitted by each of the LEDs, the non-imaging concentrators each having an entrance aperture for receiving radiation emitted by a corresponding one of the LEDs and an exit aperture from which the LEDs output emerges spatially and spectrally uniform in the near field of the exit aperture, and a light 
integrator having an entrance 
facet optically coupled to each of the exit apertures of the non-imaging concentrators for receiving radiation there through and conducting it to an exit 
facet thereof from which radiation is emitted for a downstream application, the light 
integrator being structured and arranged to substantially uniformly mix the individual beams emitted by each 
concentrator so that radiation emitted from its exit 
facet is uniformly 
colored.