Direct-write orientation of charge-transfer liquid crystals enables polarization-based coding and encryption

Abstract

Optical polarizers encompass a class of anisotropic materials that pass-through discrete orientations of light and are found in wide-ranging technologies, from windows and glasses to cameras, digital displays and photonic devices. The wire-grids, ordered surfaces, and aligned nanomaterials used to make polarized films cannot be easily reconfigured once aligned, limiting their use to stationary cross-polarizers in, for example, liquid crystal displays. Here we describe a supramolecular material set and patterning approach where the polarization angle in stand-alone films can be precisely defined at the single pixel level and reconfigured following initial alignment. This capability enables new routes for non-binary information storage, retrieval, and intrinsic encryption, and it suggests future technologies such as photonic chips that can be reconfigured using non-contact patterning.

Encryptable Electrochromic Smart Windows: Uniaxially Oriented and Polymerized Hierarchical Nanostructures Constructed by Self-Assembly of Tetrathiafulvalene-Based Reactive Mesogens

“…To investigate the optical anisotropy and birefringence of the TTFM EC device, REMS-150 equipment is used. As shown in Figure h,i, the measured intensity is converted to optical retardation ( Re = Δ nd , where Δ n is the birefringence and d is the thickness) and optical birefringence is calculated using the Cauchy equation (Δ n = A + B λ –2 , where A and B are the Cauchy constants and λ is the wavelength of light). , The Δ n is an absolute value because the uniaxially oriented TTFM has a negative anisotropy (Δ n = n e – n o < 0) with the long axis located perpendicular along to the SD. Consequently, the plot pattern in which Δ n decreases with increasing wavelength indicates that the TTFM EC device has the optical anisotropy and birefringence. − The optical behaviors of the TTFM EC device between CPs suggest that they can be used as a color-switchable optical device.…”

“…Both N and D states showed maximum A schematic illustration is presented to provide a detailed explanation of the effect of angular positioning of the TTFM device between the CPs on the transmittance (Figure 5g). 16,50,51 When the polarized light from the polarizer is parallel or perpendicular to the optic axis of the TTFM, the direction of the light does not change. The blocking of light by the analyzer perpendicular to the polarizer occurs due to the relative positioning of the optic axis and CP.…”

Optical Vector Vortex Generation by Spherulites with Cylindrical Anisotropy

“…Here we cooled it to the solid phase (columnar plastic) to explore the spherulite properties of the self-assembled films. The charge-transfer absorbance effect occurs between the donor and acceptor, − which significantly enhances the absorption along the normal of the disks and finally enables a cylindrically anisotropic extinction between the radial and azimuthal directions of the assembled spherulite. In this case, when a left circularly polarized beam transmits through the spherulite, the radially polarized component is filtered due to the strong absorption, and the remaining part is an azimuthally polarized optical vortex with a topological charge of 1, which realizes the generation of the OAM transformed from the spin angular momentum of the incidence, as shown in Figure .…”

Enhancement of association constants of various charge-transfer complexes in siloxane solvents

“…Charge-transfer (CT) complexes formed by the reversible interaction between aromatic donor (π-donor) and acceptor (π-acceptor) molecules have been widely used as crucial components and driving forces in supramolecular assemblies 1–4 and organic electronic devices 5 such as organic conductors, organic photovoltaic devices, and organic field-effect transistors. In the supramolecular field, a diversity of chemical structures and high modifiability of the aromatic molecules have assisted in the development of various architectures such as molecular machines, 1 liquid crystals, 2 supramolecular gels, 3 and foldamers.…”

“…Charge-transfer (CT) complexes formed by the reversible interaction between aromatic donor (π-donor) and acceptor (π-acceptor) molecules have been widely used as crucial components and driving forces in supramolecular assemblies 1–4 and organic electronic devices 5 such as organic conductors, organic photovoltaic devices, and organic field-effect transistors. In the supramolecular field, a diversity of chemical structures and high modifiability of the aromatic molecules have assisted in the development of various architectures such as molecular machines, 1 liquid crystals, 2 supramolecular gels, 3 and foldamers. 4 Because the strength of the aromatic donor–acceptor (D–A) interactions depends on the chemical structure and solvent nature, the determination of the association constants for various CT complexes can contribute to the design of supramolecular assemblies and allow the control of their properties, such as stimuli-sensitiveness and self-repair.…”