A lighting apparatus for providing illumination, comprising: a) an array
of surface-emitting light sources, wherein each surface-emitting light
source directs a source illumination beam, over a beam angle .theta.,
toward an illumination plane; b) an array of beam spreading optical
elements corresponding with the array of surface-emitting light sources,
wherein refraction of the source illumination beam by each beam spreading
optical element substantially satisfies a distribution function:
.times..times..theta..function..theta. ##EQU00001## wherein y is a
radial distance along the illumination plane from the optical axis of the
beam-spreading optical element, dy is an arbitrarily small increment of
the radial distance, d.theta. is the angular increment of the beam angle
corresponding to dy, and f(.theta.) is the distribution function for the
angular distribution of the light source, such that each beam spreading
optical element adjusts the luminous intensity of the source illumination
beam from the corresponding surface-emitting light source to provide a
uniformized illumination beam directed toward the illumination plane;
and, c) an array of beam-divergence reducing lens elements, wherein
each beam-divergence reducing lens element reduces the angular divergence
of a corresponding uniformized illumination beam, providing illumination
having improved uniformity and reduced beam divergence thereby.