An efficient downlight system for directing light includes a light source
and a generally tubular, hollow coupling device with an interior
light-reflective surface for receiving light from the source at an inlet
and transmitting it as a generally diverging light beam through an outlet.
The coupling device is shaped in accordance with non-imaging optics and
increases in cross sectional area from inlet to outlet in such manner as
to reduce the angle of light reflected from the surface as it passes
through the device. A thermal-isolating region has an inlet positioned in
proximity to an outlet of the coupling device and has an outlet for
passing light to an optical member. An arrangement for splitting the light
from the outlet of the thermal-isolating region comprises a plurality of
light guides. Each light guide includes an inlet end for receiving light
from the thermal-isolating region and an outlet end for directing light to
a remote location. The inlet ends are substantially coplanar with each
other and form a substantially solid shape. The coupling device and
thermal-isolating region are shaped so as to distribute a respective,
substantial (i.e., useful) amount of light to each of the plurality of
light guides. Efficiencies of about 30 lumens per watt may be achieved.