We report the observation of plasmonic modes of annular resonators in nanofabricated Ag and Au surfaces that are imaged by spectrally resolved cathodoluminescence. A highly focused 30 keV electron beam is used to excite localized surface plasmons that couple to collective resonant modes of the nanoresonators. We demonstrate unprecedented resolution of plasmonic mode excitation and by combining ...

Controllable switching between metastable macroscopic quantum states under nonequilibrium conditions induced either by light or with an external electric field is rapidly becoming of great fundamental interest. We investigate the relaxation properties of a "hidden" (H) charge density wave (CDW) state in thin single crystals of the layered dichalcogenide 1T-TaS2, which can be reached by either a...

When cells are irradiated with visible and near-infrared wavelengths a variety of stimulatory effects are observed in their metabolism. To explain the observed light effects, researchers try to identify the chromophores that are involved in the processes. However, the mechanism of light absorption by a chromophore does not explain many of the experimental observations and therefore the primary ...

In this paper, some aspects of choosing excitation signals for fast measurement of complex electrical impedance of objects, including impedance of biological tissues, over a wide range of frequencies are discussed. For this purpose, several short-time excitation signals as special cases of chirp signals of near to minimal duration are proposed. The results of analysis and simulation are promisi...

We use the magnetic field distribution of an azimuthally polarized focused laser beam to excite a magnetic dipole transition in Eu^{3+} ions embedded in a Y2O3 nanoparticle. The absence of the electric field at the focus of an azimuthally polarized beam allows us to unambiguously demonstrate that the nanoparticle is excited by the magnetic dipole transition near 527.5 nm. When the laser wavelen...

We report on time-resolved mid-infrared (mid-IR) near-field spectroscopy of the narrow bandgap semiconductor InAs. The dominant effect we observed pertains to the dynamics of photoexcited carriers and associated surface plasmons. A novel combination of pump-probe techniques and near-field nanospectroscopy accesses high momentum plasmons and demonstrates efficient, subpicosecond photomodulation ...

Lifetime-limited optical excitation lines of single nitrogen-vacancy (NV) defect centers in diamond have been observed at liquid helium temperature. They display unprecedented spectral stability over many seconds and excitation cycles. Spectral tuning of the spin-selective optical resonances was performed via the application of an external electric field (i.e., the Stark shift). A rich variety ...

We used the high local electric fields at the junction between the suspended and supported parts of a single carbon nanotube molecule to produce unusually bright infrared emission under unipolar operation. Carriers were accelerated by band-bending at the suspension interface, and they created excitons that radiatively recombined. This excitation mechanism is approximately 1000 times more effici...

In this work, we analyze modified bowtie nanoantennas with polynomial sides in the excitation and emission regimes. In the excitation regime, the antennas are illuminated by an incident plane wave, and in the emission regime, the excitation is fulfilled by infinitesimal electric dipole positioned in the gap of the nanoantennas. Several antennas with different sizes and polynomial order were num...

The dynamics of charge transfer at interfaces are fundamental to the understanding of many processes, including light conversion to chemical energy. Here, we report imaging of charge carrier excitation, transport, and recombination in a silicon p-n junction, where the interface is well defined on the nanoscale. The recorded images elucidate the spatiotemporal behavior of carrier density after o...