An illumination system is disclosed, which includes a first light source and a
second light source configured to emit light when the first light source is not
emitting light. A polarizing element accepts light from the first and second light
sources. The polarizing element emits, along a light path, light from the first
light source with a first polarization orientation. The polarizing element emits,
along the light path, light from the second light source with a second polarization
orientation. A homogenizing element receives and homogenizes polarized light from
the polarizing element. A polarization rotator receives light from the homogenizing
element. The polarization rotator selectively rotates one of the first and second
polarization orientations to ensure light emitted therefrom maintains a constant
polarization orientation.