Abstract: The invention relates to poly(phenylene vinylene) polymers substituted with dendritic sidechains to enhance main-chain separation in the solid state. The polymers are synthesized by the Heck polymerization and have a weight-average molecular weight of 20,000 to 60,000 Daltons. The polymers are self-ordering in the solid state and have thermotropic liquid crystalline phases. The polymers show enhanced photoconductivity, better charge transport capability and improved polarized light emission.

Abstract: This invention is predicated upon applicants' discovery that the performance of thermally adjustable fiber grating devices is enhanced by disposing them within a vessel for thermal isolation. The vessel is sufficiently larger than the fiber to avoid contact with the grating yet sufficiently small to isolate the grating from substantial air currents. Conveniently, the vessel is a cylindrical tube having elastomeric end seals. Advantageously microcapillary tubes passing through the elastomeric seals provide openings for the fiber to pass through the tube.

Abstract: In accordance with the invention, an optical fiber grating device is made by providing a fiber with an electrically actuable component optically responsive to voltage or current and a plurality of conductive elements to locally activate the component and thereby to produce local optical perturbations in the fiber. In a preferred embodiment, a fiber is provided with a core of liquid crystal material and a plurality of periodically spaced microelectrode pairs. Application of a voltage to the microelectrodes results in a periodic sequence of perturbations in the core index which produces a grating. When the voltage is switched off, the grating switches off. Other embodiments utilize helical conductive elements.

Abstract: In accordance with the invention, an electrically modifiable optical fiber grating device is made by providing a fiber including a grating and forming a plurality of electrically conductive elements along the grating. In response to an electrical signal, the conductive elements modify the grating. In a preferred embodiment, a fiber grating is provided with a plurality of heating elements spaced to selectively heat different portions of the grating. This chirps the spacing between elements of the grating and thereby increases the bandwidth of the device.

Abstract: A novel PDLC film composition that contains a mixture of acrylate monomers that provide certain advantages when combined with a liquid crystal. The mixture of acrylate monomers contains one monofunctional monomer that gives rise to a homeotropic anchoring condition, and one monofunctional monomer that gives rise to homogeneous anchoring condition in the PDLC film made from the composition of the present invention at a selected temperature. The monomer mixture also contains a polyfunctional acrylate monomer. PDLC films made from these compositions have advantages over films made from compositions that have only one monofunctional acrylate monomer. Also, by using the process of the present invention, one can prepare a PDLC film that exhibits a low switching voltage in a desired temperature range.