Azo-carbazole copolymer-based composite films for rewritable vector holograms

Abstract

Vector holography has emerged as a promising technique that unlocks the polarization degree of freedom of light to be used for generating, storing, and reproducing information. Vector holograms with rewritable capabilities are desirable in applications such as optical computing, data storage, dynamic beam shaping, optical communication, etc. However, the development of materials for rewritable vector holography poses significant challenges. Materials such as photopolymers and metamaterials for vector holograms show good performance and long-term storage capabilities but do not possess rewritable capabilities. On the other hand azo-based polymers, azobenzene liquid crystals, and photorefractive polymers are rewritable but often fail to satisfy other requirements such as higher diffraction efficiency, faster response, stability, and long-term storage, etc., simultaneously. In this study, we have investigated the potentials of azo-carbazole copolymer film for vector holography applications by conducting a thorough study on its polarization recording/reconstruction characteristics, for the first time. We found that the material exhibits a higher diffraction efficiency, reaching up to 85%, with good stability. The recording requires only a short exposure of 5 seconds, using laser power of a few milliwatts/cm2. Our findings indicate that the proposed azo-carbazole polymer material holds great potential for evolving into the ‘rewritable vector holography recording material’ for the future, and is capable of advancing the field of vector holography and related applications.