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Full-Text Articles in Physics
Confined Photonic Mode Propagation Observed In Photoemission Electron Microscopy, Theodore Stenmark, Robert Campbell Word, Rolf Konenkamp
Confined Photonic Mode Propagation Observed In Photoemission Electron Microscopy, Theodore Stenmark, Robert Campbell Word, Rolf Konenkamp
Physics Faculty Publications and Presentations
Using photoemission electron microscopy (PEEM) we present a comparative analysis of the wavelength dependence of propagating fields in a simple optical slab waveguide and a thin film photonic crystal W1-type waveguide. We utilize an interferometric imaging approach for light in the near-ultraviolet regime where a 2-photon process is required to produce photoelectron emission. The typical spatial resolution in these experiments is < 30 nm. Electromagnetic theory and finite element simulations are shown to be in good agreement with the experimental observations. Our results indicate that multiphoton PEEM is a useful sub-wavelength characterization technique in thin film optics.
Ion Transport Across Biological Membranes By Carborane-Capped Gold Nanoparticles, Marcin P. Grzelczak, Stephen P. Danks, Robert C. Klipp, Domagoj Belic, Adnana Zaulet, Casper Kunstmann-Olsen, Dan F. Bradley, Tatsuya Tsukuda, Clara ViñAs, Francesc Teixidor, Jonathan J. Abramson, Mathias Brust
Ion Transport Across Biological Membranes By Carborane-Capped Gold Nanoparticles, Marcin P. Grzelczak, Stephen P. Danks, Robert C. Klipp, Domagoj Belic, Adnana Zaulet, Casper Kunstmann-Olsen, Dan F. Bradley, Tatsuya Tsukuda, Clara ViñAs, Francesc Teixidor, Jonathan J. Abramson, Mathias Brust
Physics Faculty Publications and Presentations
Carborane-capped gold nanoparticles (Au/carborane NPs, 2–3 nm) can act as artificial ion transporters across biological membranes. The particles themselves are large hydrophobic anions that have the ability to disperse in aqueous media and to partition over both sides of a phospholipid bilayer membrane. Their presence therefore causes a membrane potential that is determined by the relative concentrations of particles on each side of the membrane according to the Nernst equation. The particles tend to adsorb to both sides of the membrane and can flip across if changes in membrane potential require their repartitioning. Such changes can be made either with …