Low-cost liquid crystal display optimized as a monopixel coherent modulator

Abstract

We propose the use of low cost alphanumeric liquid crystal displays (LCD) not only as an educational tool, to introduce students the insights of the electrooptic performance of liquid crystals, but also as a device able to be used in research to validate models describing the performance of LCDs and to be used in applications requiring monopixel optical modulation. High resolution LCDs have usually focused the research attention because of their capabilities to be used as SLMs. However low cost LCDs with a low number of pixels and directly addressed, such as segmented alphanumeric displays, may also be appealing devices. We show the characterization of one of the segments. The model applied had previously been demonstrated with high resolution LCDs, which are thin LCDs. The segmented LCD is found to be a thick LCD, thus, allowing us to verify the validity of the model in another range of conditions. Furthermore, we show that low cost alphanumeric LCDs can be used as monopixel LCDs. This is interesting since there are a number of applications, as in polarimetry or in interferometry, where monopixel LCDs may proof necessary. We optimize the modulation of the LCD both in the transmissive and in the reflective geometry to obtain amplitude-only and phase-only modulations which are useful for a number of applications.