Holographic Imaging in Carbon Nanotube and Dye-Doped Liquid Crystal

Without application of electric field, we recorded permanent holographic images in the nematic liquid crystal E7, doped with 0.6{\%} Methyl Red (MR) \textit{and} 0.002{\%} single-wall carbon nanotubes (CNTs). The images were recorded using a 488-nm laser and reconstructed using 488-nm, 532-nm and 633-nm probe beams. Multi-order diffraction patterns were observed, during image recording and reconstruction, for thin films having thicknesses of 15 $\mu $m. The quality and diffraction efficiency were higher for cells containing both CNTs and MR than for cells doped only with MR. Average first-order diffraction efficiencies of 7.1{\%} and 3.7{\%} were found for the (CNT+MR)-cells and MR-only cells, respectively. The primary objective of this study was to utilize the molecular properties of MR and CNTs to produce a liquid crystal material with improved holographic properties. Dynamics of image formation and a proposed CNT-enhancement mechanism are presented. The holograms are robust and have remained stable for over two years.