LCD and LCoS spatial light modulators must have linearly polarized light to work properly. However most light sources for digital projectors produce unpolarized light, rather than losing 50% of the optical power of the lamp, a polarization conversion system (PCS) can be used to produce nearly perflectly polarized light. This article describes how PCS systems work, how they are modeled in ZEMAX, and how they are integrated into digital projectors.

This article discusses the design issues involved in designing fly's eye spatial light integrators, with specific application to the design of digital projectors.