Fluorescence and Phosphorescence Dual-Emission Liquid Crystal Polymer Optical Waveguide for Logical Gate.

Information security has emerged as a critical concern in contemporary society. Leveraging optical logic gates with dual-emission characteristics offers a promising approach to enhancing information security. However, designing active optical waveguide materials (OWMs) capable of fluorescence-phosphorescence dual emission remains a significant challenge. In this study, we present a room-temperature phosphorescent liquid crystalline polymer (RTP LCP) as active OWMs exhibiting fluorescence-phosphorescence dual emission and a low optical loss coefficient (OLC) for implementation in optical logic gates. The resulting RTP LCP exhibits a smectic phase between 25 °C and 90 °C, followed by nematic phase between 90 °C and 110 °C, with a phosphorescence lifetime of 2.77 ms. Subsequently, the RTP LCP is processed into oriented liquid crystal fibers and encapsulated in polymethyl methacrylate. Optical waveguide experiments demonstrate that these oriented liquid crystal fibers exhibit fluorescence-phosphorescence dual emission, with low OLCs of 0.20 dB/mm at 490 nm and 0.17 dB/mm at 565 nm. Furthermore, these dual-emission active OWMs are successfully applied to optical logic gates. This work holds significant implications for the development of active OWMs with fluorescence-phosphorescence dual emission, advancing their potential applications in optical logic gates.