Advanced electrotunable linear polarization rotator with high degree of linear polarization using dye-doped 90°-twisted nematic liquid crystals

Abstract

Considerable attention has been allotted to the generation and manipulation of polarization light due to its unique optical properties and potential applications. Nevertheless, existing polarization rotators are limited in their capability to provide continuous linear polarization rotation and maintain a high degree of linear polarization (DoLP) via electric stimuli, and this condition is severely inherent in their system design flexibility. In this study, we enhance the performance of a continuously electrotuneable linear polarization rotator by utilizing dye-doped 90°-twisted nematic liquid crystals (90°-TNLCs). Despite a slight decrease in light intensity under an electric stimulus, the polarization rotators maintain a consistently high DoLP due to the dichroic dye's absorption anisotropy and the selective absorption of elliptically polarized transmitted light along the short axis. This mechanism effectively migrated the degradation of DoLP. Additionally, we investigated the comparative absorption characteristics between 90°-twisted nematic and homogeneous alignment LCs. This pioneering innovation offers unprecedented versatility in linear polarization control, which paves the way for advanced application in polarization modulation technologies.