An illumination system including a light source, a light guide including
an output surface, a first interference reflector positioned between the
light source and the output surface of the light guide, and emissive
material positioned between the first interference reflector and the
output surface of the light guide is disclosed. The light source emits
light having a first optical characteristic. The first interference
reflector substantially transmits light having the first optical
characteristic and substantially reflects light having a second optical
characteristic. The emissive material emits light having the second
optical characteristic when illuminated with light having the first
optical characteristic.