Alberto G Curto

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Nanoscale quantum emitters are key elements in quantum optics and sensing. However, efficient optical excitation and detection of such emitters involves large solid angles because their interaction with freely propagating light is omnidirectional. Here, we present unidirectional emission of a single emitter by coupling to a nanofabricated Yagi-Uda antenna.(More)
The ability to detect light over a broad spectral range is central to practical optoelectronic applications and has been successfully demonstrated with photodetectors of two-dimensional layered crystals such as graphene and MoS2. However, polarization sensitivity within such a photodetector remains elusive. Here, we demonstrate a broadband photodetector(More)
Multipolar transitions other than electric dipoles are generally too weak to be observed at optical frequencies in single quantum emitters. For example, fluorescent molecules and quantum dots have dimensions much smaller than the wavelength of light and therefore emit predominantly as electric dipoles. Here we demonstrate controlled emission of a quantum(More)
By directing light, optical antennas can enhance light-matter interaction and improve the efficiency of nanophotonic devices. Here we exploit the interference among the electric dipole, quadrupole, and magnetic dipole moments of a split-ring resonator to experimentally realize a compact directional optical antenna. This single-element antenna design(More)
Nanostructured metallic films have the potential to replace metal oxide films as transparent electrodes in optoelectronic devices. An ideal transparent electrode should possess a high, broadband, and polarization-independent transmittance. Conventional metallic gratings and grids with wavelength-scale periodicities, however, do not have all of these(More)
Plasmon-mediated long-range coupling of optical excitations is shown to be attainable using near-field phase antennas involving nanoparticles situated at focal spots. The antennas rely on metal-surface features that are geometrically arranged to produce constructive interference of plasmons emanating from a source spot over a designated image position.(More)
We investigate the near-field focusing properties of three-dimensional phase antennas consisting of concentric rings designed to have source and image spots separated by several microns from the lens. Tight focal spots are obtained for silicon or gold rings patterned in a silica matrix. We analyze in detail the dependence of the performance of these lenses(More)
We address experimentally the radiation patterns of quantum dots coupled to optical nanoantennas at specific positions. We show that the emission of the coupled system is determined by a variety of resonant and non-resonant antenna modes both in polarization and angular pattern. The first working optical Yagi-Uda antenna is presented and unidirectional(More)
Summary form only given. By directing light, optical antennas can enhance light-matter interaction and improve the efficiency of nanophotonic devices. Though several designs have been presented<sup>1</sup>, most of them have been scaled-down radio frequency antennas which have narrow bandwidths and are sensitive to the position of the coupled emitters. Here(More)
The nature of the highly efficient energy transfer in photosynthetic light-harvesting complexes is a subject of intense research. Unfortunately, the low fluorescence efficiency and limited photostability hampers the study of individual light-harvesting complexes at ambient conditions. Here we demonstrate an over 500-fold fluorescence enhancement of(More)