Finland-Japan Workshop on Nanophotonics and Related Technologies : Espoo, Finland, 1st and 2nd of July 2009

Liquid Crystal on Silicon (LCOS) microdisplay is typically less than 1⁄2 inch in diameter and are used in Near to Eye Displays or in Picoprojectors. These displays are reflective and the control of light in each pixel is based on change of the polarization of light in the liquid crystal material. The reflective nature of the display requires using Polarization Beam Splitters (PBS) in illumination which enlarges the back focal length of optics and reduces the compactness of the system. In this paper the use of polarization maintaining lightguide instead of the PBS is studied. The back focal length is shortened and the system is more compact. The problem is to design the lightguide so that the contrast of the system is kept in acceptable level. In the ray tracing study the rigorous coordinate transformation method is used in polarization and efficiency calculations.