Fringing Field Effect and the measurement of the subpixel jones matrices of an LCD

Liquid Crystal Displays (LCD) are commonly employed as computer-generated holograms (CGH) in active optical systems to manipulate the phase of light. Since reflective Liquid Crystals on Silicon (LCoS) displays are manufactured today with pixelsizes of few micrometers, subpixel-effects gain in importance. One major effect is the fringing field effect, which is the major type of crosstalk between neighbouring pixels so that the liquid crystals of pixel B get influenced by the electric field of pixel A. As a result a desired sharp phasestep between two pixels gets blurred so that the computed hologram is not displayed exactly. Thus, the diffraction efficiency decreases. For higher diffraction efficiency the fringing field effect must be considered during the computation of the CGH and, therefore, it is necessary to measure the effect. In the following an optical setup is presented for measuring the subpixel jones matrices of an LCD. Afterwards a simulation model based on the results is shown.