Characterization of a low resolution liquid crystal display to be used as an optical modulator

Monopixel liquid cristal displays are interesting devices in many applications, such as variable retarder, variable attenuator, etc. In contrast with high resolution liquid crystal displays (LCDs), in these devices the voltage is directly addressed to each pixel. This makes them a very useful device to study the electrooptic performance of LCDs. In this work we focus on the analysis of the modulation properties of one of the segments of a very low cost alphanumeric display. We want to verify if there are differences between this low resolution LCD and the results and modelling obtained in the literature for high resolution LCDs. Furthermore, we want to analyse if the display can be applied as a phase-only modulator and as an amplitude-only modulator. We have found that the thickness of the LCD is double than the usual value for high resolution LCDs. This has allowed to verify for the first time the validity of a model previously demonstrated for thin LCDs. The modulation dynamic range, in particular for the phase, is enhanced by this larger thickness. We have obtained phase-only modulation and amplitude-only modulation configurations with this thick LCD using a long wavelength (633 nm).