Photothermal heterodyne imaging of micron-sized objects.

Micron-sized dye-doped polymer beads were imaged using transmitted/reflected light microscopy and photothermal heterodyne imaging (PHI) measurements. The transmitted/reflected light images show distinct ring patterns that are attributed to diffraction effects and/or internal reflections within the beads. In the PHI experiments pump laser induced heating changes the refractive index and size of the bead, which causes changes in the diffraction pattern and internal reflections.

Chemical interface damping for propagating surface plasmon polaritons in gold nanostripes.

Leakage radiation microscopy has been used to examine chemical interface damping (CID) for the propagating surface plasmon polariton (PSPP) modes of Au nanostripes-nanofabricated structures with heights of 40 or 50 nm, widths between 2 and 4 µm, and 100 µm lengths. Real space imaging was used to determine the propagation lengths L of the leaky PSPP modes, and back focal plane measurements generated ω vs k dispersion curves, which yield the PSPP group velocities v. The combination of these two experiments was used to calculate the PSPP lifetime via T = L/v.

Making waves: Radiation damping in metallic nanostructures.

Metal nanostructures display several types of resonances. In the visible and near-IR spectral regions, there are localized surface plasmon resonances (LSPRs) that involve the coherent oscillation of the conduction electrons. Extended metal nanostructures, such as nanowires or nanoplates, also exhibit propagating surface plasmon polaritons (PSPPs), which are motions of the electrons at the surface of the structure that have a well-defined momentum.

Ultrafast measurements of the dynamics of single nanostructures: a review.

The ability to study single particles has revolutionized nanoscience. The advantage of single particle spectroscopy measurements compared to conventional ensemble studies is that they remove averaging effects from the different sizes and shapes that are present in the samples. In time-resolved experiments this is important for unraveling homogeneous and inhomogeneous broadening effects in lifetime measurements.

Strong Exciton-Plasmon Coupling in Silver Nanowire Nanocavities.

The interaction between plasmonic and excitonic systems and the formation of hybridized states is an area of intense interest due to the potential to create exotic light-matter states. We report herein coupling between the leaky surface plasmon polariton (SPP) modes of single Ag nanowires and excitons of a cyanine dye (TDBC) in an open nanocavity. Silver nanowires were spin-cast onto glass coverslips, and the wavevector of the leaky SPP mode was measured by back focal plane (BFP) microscopy.