An enhanced light fixture containing a volumetric, anisotropic diffuser to
control the spatial luminance uniformity and angular spread of light from
the light fixture is disclosed. The anisotropic diffuser provides
increased spatial luminance uniformity and efficient control over the
illuminance such that power reductions, reduced cost or reduced size may
be achieved. The anisotropic diffuser contains one or more regions of
asymmetrically shaped light scattering particles. The spread of
illumination of light from a light emitting source can be efficiently
controlled by using a thin, low cost, volumetric, asymmetric diffuser to
direct the light in the desired direction. This allows the reduction in
number of light sources, a reduction in power requirements, or a more
tailored illumination. When the anisotropic diffuser is used in
combination with a waveguide to extract light, the light is efficiently
coupled out of the waveguide in a thin, planar surface. This transmissive
diffuser can be coupled to a reflecting element such that the resulting
combination is a light reflecting element with a desired asymmetric light
scattering profile.