The combination of solid-state light sources like light-emitting diodes (LEDs) and lasers, with microdisplays like liquid-crystal-on-silicon (LCOS) devices is leading to the development of electronic projectors small enough to be embedded in, for example, the handset of a mobile phone. In such “pico projectors,” small optical engine size and high optical efficiency are especially important. Achieving size and efficiency goals requires new ways of managing polarized light to illuminate and image microdisplay panels. It would increase the efficiency of such optical systems if they could efficiently use unpolarized light to illuminate a display that ordinarily requires polarized light, particularly if this could be accomplished without doubling the étendue of the light source.
It is against this background that the teachings disclosed herein have been developed.