An optical manifold for efficiently combining a plurality of blue LED
outputs to illuminate a phosphor for a single, substantially homogeneous
output, in a small, cost-effective package. Embodiments are disclosed
that use a single or multiple LEDs and a remote phosphor, and an
intermediate wavelength-selective filter arranged so that backscattered
photoluminescence is recycled to boost the luminance and flux of the
output aperture. A further aperture mask is used to boost phosphor
luminance with only modest loss of luminosity. Alternative non-recycling
embodiments provide blue and yellow light in collimated beams, either
separately or combined into white.