Etendue efficient illuminator with a retro-reflecting aperture

In this paper the etendue efficient illuminator having retro-reflecting aperture with a slit is proposed. Such an illuminator allows to increase light efficiency of the projection system which has an etendue much smaller than the arc lamp used typically as the light source. In modeling and analysis results, it is evaluated that retro-reflecting aperture with a slit make it possible to increase light efficiency of single panel color scrolling projection system by about 15%.