Modulación completa del plano complejo mediante pantallas de cristal líquido. Aplicación a la representación de hologramas de Fresnel digitales.

Abstract

"In this work we analyze the use of liquid crystal devices to obtain full modulation of the complex plane. This full complex modulation is used to display digital Fresnel holograms. First we analyze the behaviour of the reconstruction of Fresnel holograms at several distances using only part of the complex information: amplitude, phase, real or imaginary part. We also present the models of the liquid crystal devices used and the different working configurations using two coupled devices to obtain full complex modulation of the complex plane. The first system uses two transmissive devices in a cascade architecture, which we use two different methods to adjust the amplitude and the phase that represent the information of the hologram. The next system uses the addition of two reflective ferroelectric devices in a Michelson interferometer configuration, obtaining the full complex modulation by adding the real and imaginary parts. The last system uses the addition of two transmissive devices with different operating curves than the only-real or the only-imaginary. The setup with the two devices is like a Mach-Zehnder interferometer. In all cases simulated and experimental results are presented."