Non-Technical Abstract The aim of Photonics is to trap, steer, direct, switch and control light in much the way that electrons are manipulated in electronics. Eventually fast, highly efficient circuits, memories and processing may be done photonically, that is optically. To trap visible light requires a highly symmetric, almost spherical, structure with elementary units with dimensions about 1/100 th the width of a human hair (.0005 mm, the wavelength of green light). The most spherical ordered symmetry is icosahedral, the same as a soccer ball, with 12 five fold faces. This proposal aims at developing the advanced techniques to make a complex icosahedral structure at these small length scales. It makes use of new developments in manipulating small particles using laser beams through a microscope lens, "laser Tweezers", and in photochemistry of polymers. The theory, which has so far proven elusive for such complex structures, will be explored analytically and computationally. Moreover, part of the project is to explore the question of finding the optimal structures (rods, spheres, smooth surfaces) with this symmetry. Students from high school to postdoc will participate in the research which is generally "table-top" and involves fundamental ideas from the very basic to the frontiers of math and physics.
This proposal is directed toward designing and fabricating photonic quasicrystals for use in trapping and controlling light. Such control of photons is important both technologically and for advancing fundamental research. Quasicrystals are the best candidates for achieving a complete three-dimensional photonic band gap because of their high degree of rotational symmetry. Complex three-dimensional quasicrystalline heterostructures with sub-micrometer features can be constructed from photopolymerized colloidal dispersions using recently developed holographic optical trapping techniques The proposed research will address basic questions regarding the physics of quasicrystals, and the materials science of soft heterostructure fabrication. Included are experimental and theoretical studies of the photonic properties of quasiperiodic solids, the role of symmetry in the interaction of light and matter, and mathematical and computational methods for design optimization. With an aim toward produce useful devices, advanced tools and techniques will be developed for holographic manufacturing, template-guided three-dimensional self-organization, selective and directional colloidal bonding, and photopolymerization. Students from high school to postdoc will participate in the research.
