Investigations of Switchable Mesoscale Lattices for Photonics

Brown University, Providence RI

Investigators

Abstract

0322878 Crawford This proposal focuses on discovery and application of two- and three-dimensionally structured holographically formed polymer dispersed liquid crystals (H-PDLC) for the creation of electrically switchable mesoscale lattices targeted at photonic crystal (PhC) and diffractive optical applications. H-PDLC materials exhibit fast switching (<100 ms), low absorption in the visible and near IR, high diffraction efficiency, tunable refractive index profiles, and simple and inexpensive one step fabrication. Holographic-lithography at 351 nm or 532 nm is proposed to generate optical lattices that are permanently captured in holographic-polymer dispersed liquid crystals through a photo-diffusion phase-separation process. The PI will perform temporal multiplexing exposure techniques to mimic nature and build artificial lattices. One such lattice, which has been shown to exhibit lasing, is known as the liquid crystal blue phase (BP). The BP is stable on the temperature scale between the helical cholesteric phase and the isotrophic phase, where a highly ordered 3D lattice is found. Other proposed lattice configurations include the diamond lattice, superimposed lattices, quasilattices, and superlattices, with investigations focusing on their application potential (e.g. lasing, waveguides, strain-gauges). By cooperating with the local Chapters of the Women in Science and Engineering (WiSE) and the National Society for Black Engineers (NSBE), the research findings can be broadly disseminated to underrepresented groups in science and engineering through forums and presentations. In addition, a module will be created for K-12 students and teachers to demonstrate how lattices self organize, and to integrate lattice formation with art for younger children. A conference will be organized on photonics and entrepreneurship at Brown University to bring together faculty, industry, students, and the investment community to show university researchers how to potentially create value out of their basic photonics research.