A lighting system and device for providing indirect light using free-cavity,
double-diffusing
configurations are disclosed. In accordance with the embodiments of the invention,
a lighting fixture comprises a cover structure with a diffusion layer and a reflective
plate that form the free-cavity. The free-cavity is preferably configured to provide
an output of light from a light source positioned within the free-cavity with an
efficiency rating of 70% or more and provide better than an 8:1 ceiling lighting
contrast between the rows of fixtures with rows on 16 feet spacing. Further, in
accordance with a preferred embodiment of the invention, a device is configured
to couple to a ceiling structure and provide the indirect lighting from a fluorescent
light source.