Optimal design of achromatic true zero-order waveplates using twisted nematic liquid crystal

Phase retarders usually show strong wavelength dependence. A novel and simple configuration with the combination of two twisted nematic liquid-crystal cells is proposed for the design of a true zero-order achromatic quarter-wave plate. The present optimization method considers the material dispersion. Simulation computations show a good achromatic behavior of the optimized waveplate. Compared with other types of broadband quarter-wave plates, the present device is compatible with classical liquid-crystal displays and can be expected to be used in precision polarimeters with low cost and enhanced light efficiency.