TRANSMISSION AND PHASE MEASUREMENT FOR POLARIZATION EIGENVECTORS IN TWISTED-NEMATIC LIQUID-CRYSTAL SPATIAL LIGHT MODULATORS

Recently we published theoretical expressions for the eigenvalues and eigenvectors for a twisted-nematic liquid crystal spatial light modula tor (LCSLM) as a function of the twist angle and birefringence using t he Jones matrix formalism. These polarization eigenvectors are of inte rest for newer video graphics adapter (VGA) resolution (640 x 480 pixe ls) LCSLMs that are thinner and consequently have a lower birefringenc e. Although these devices can produce excellent amplitude modulation, they cannot achieve phase-only modulation using linearly polarized lig ht. In these cases, the polarization eigenvectors are required to obta in phase-only modulation. We present experimental measurements for bot h the transmission and phase shift for these polarization eigenvectors . These results are in excellent agreement with theory and show that p hase-only modulation can be obtained for these high-resolution LCSLMs. (C) 1998 Society of Photo-Optical instrumentation Engineers. [S0091-3 286(98)00411-5].