A thin-profile, optically efficient lighting device for use with, among
other things, flat information displays, includes a combination of three
optically coupled light propagating structures, fabricated of
electromagnetic flux transmitting materials. The first structure may be a
generally elongated optical pipe adapted to receive light from at least
one light source such as a light emitting diode. Radiation from
additional sources is coupled into the first structure by a second
structure which injects the radiation thereinto. Light injected into the
first structure is directed into the third structure where it is
redirected so that it propagates out of the third structure uniformly and
efficiently and in a direction that is substantially perpendicular to the
surface of the third structure. A device can include multiple bodies of
any or all three structures.