A lighting apparatus for providing area illumination of high uniformity and power density, said lighting apparatus comprising: a high thermal conductivity printed circuit board; at least one bare LED die comprising one or more LED emitting areas for generating radiation of one or more spectral bands over a predetermined solid angle, said at least one bare LED die being attached to said high thermal conductivity printed circuit board with a thermally conductive bonding layer; an electronic control module attached to said high thermal conductivity printed circuit board for controlling the output of said LED emitting areas; at least one non-imaging concentrator fixedly attached to and in registration with said high thermal conductivity printed circuit board, said non-imaging concentrator having entrance and exit apertures, said non-imaging concentrator entrance aperture being optically aligned with said LED emitting areas for collecting radiation from said LED emitting areas and re-emitting it through said non-imaging concentrator exit aperture with an etendue substantially the same as that of said LED emitting areas, said non-imaging concentrator operating to homogenize the LED output to provide at the non-imaging concentrator exit aperture a high degree of near field intensity uniformity and a reduced far field extent substantially preserving the etendue of the LED output; and a relay lens for imaging the near field of said non-imaging concentrator to an illumination plane a predetermined distance away from said non-imaging concentrator exit aperture, wherein: said exit aperture of said non-imaging concentrator comprises transparent apertures and reflective surfaces interspersed between said transparent apertures such that radiation impinging on the reflective surfaces and not in the apertures is directed back towards said LED emitting area. a high thermal conductivity printed circuit board; at least one bare LED die comprising one or more LED emitting areas for generating radiation of one or more spectral bands over a predetermined solid angle, said at least one bare LED die being attached to said high thermal conductivity printed circuit board with a thermally conductive bonding layer; an electronic control module attached to said high thermal conductivity printed circuit board for controlling the output of said LED emitting areas; at least one non-imaging concentrator fixedly attached to and in registration with said high thermal conductivity printed circuit board, said non-imaging concentrator having entrance and exit apertures, said non-imaging concentrator entrance aperture being optically aligned with said LED emitting areas for collecting radiation from said LED emitting areas and re-emitting it through said non-imaging concentrator exit aperture with an etendue substantially the same as that of said LED emitting areas, said non-imaging concentrator operating to homogenize the LED output to provide at the non-imaging concentrator exit aperture a high degree of near field intensity uniformity and a reduced far field extent substantially preserving the etendue of the LED output; and a relay lens for imaging the near field of said non-imaging concentrator to an illumination plane a predetermined distance away from said non-imaging concentrator exit aperture, wherein: said exit aperture of said non-imaging concentrator comprises transparent apertures and reflective surfaces interspersed between said transparent apertures such that radiation impinging on the reflective surfaces and not in the apertures is directed back towards said LED emitting area.