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.