LCD characterization and optimization for efficient hologram reconstructions

We present a method for measuring all eight parameters (including the signs) of the Jones matrices of liquid crystal displays. The method can be applied to measure the Jones matrices for all addressable gray-levels thus delivering the specifications needed for calculating characteristic curves for arbitrary input and output polarizations. Unlike other approaches we do not rely on a physical model of the LCD. Therefore, it is possible to measure the Jones matrices of a more complex optical system in one step, e.g. when a reflective LCD is used in combination with a beam splitter. The results of the simulated characteristic curves for a twisted-nematic LCD were verified by measurement and then used for optimizing phase-only computer-generated Fourier holograms. To this end modifications of the iterative Fourier transform algorithm and binary search are employed. These algorithms take into account the geometric phase that is due to the gray-level dependent polarization modifications that are introduced by the LCD.