Liquid-crystal-on-silicon (LCOS) technology delivers increased performance compared to other technologies, and using a number of subwavelength optical elements, such as prepolarizers, polarizing beamsplitters and trim retarders, can further enhance the performance of LCOS displays. A prepolarizer polarizes light from the projection lamp source in the polarized light engine. An excellent polarizer is a metal subwavelength optical element, or wire grid, which effectively divides two orthogonal polarizations from a light source. Optimum light collection from the source is ensured because of its wide angle acceptance. In contrast to stretched polymer or crystal polarizers, the subwavelength polarizer allows a device to be used interchangeably for red, green and blue channels. In addition, the subwavelength polarizer offer improved thermal and UV handling capability. Wire-grid technology can replace the classic MacNeille-type glass polarizer for use in a polarizing beamsplitter in the LCOS light engine. Unlike a MacNeille polarizer, wire-grid polarizing beamsplitter offers the following advantages: a large acceptance angle, an extensive operating spectrum, and resistance to the impact of poor performance due to temperature. A trim retarder is the latest addition to the wavelength elements for LCOS displays. A trim retarder makes up for the minimal residual birefringes demonstrated by an LCOS panel. Various subwavelength elements have been proven to improve the contrast of LCOS displays. They provide the extra benefits of compact size and environmental durability.