Purcell effect in active diamond nanoantennas.

We suggest a novel class of active nanoantennas based on diamond nanoparticles with embedded nitrogen-vacancy centres coupled to Mie resonances of nanoparticles. We theoretically study the optical properties of such nanoantennas including the field enhancement and Purcell effect, and experimentally demonstrate the enhancement of the fluorescence rate of the emitters due to particle resonances, as compared to a nonresonant regime. Our results pave the way towards active dielectric nanophotonics for quantum light sources, bioimaging, and quantum information processing.

Light-Emitting Halide Perovskite Nanoantennas.

Nanoantennas made of high-index dielectrics with low losses in visible and infrared frequency ranges have emerged as a novel platform for advanced nanophotonic devices. On the other hand, halide perovskites are known to possess high refractive index, and they support excitons at room temperature with high binding energies and quantum yield of luminescence that makes them very attractive for all-dielectric resonant nanophotonics. Here we employ halide perovskites to create light-emitting nanoantennas with enhanced photoluminescence due to the coupling of their excitons to dipolar and multipolar Mie resonances. We demonstrate that the halide perovskite nanoantennas can emit light in the range of 530-770 nm depending on their composition. We employ a simple technique based on laser ablation of thin films prepared by wet-chemistry methods as a novel cost-effective approach for the fabrication of resonant perovskite nanostructures.

Nanoscale Generation of White Light for Ultrabroadband Nanospectroscopy.

Achieving efficient localization of white light at the nanoscale is a major challenge due to the diffraction limit, and nanoscale emitters generating light with a broadband spectrum require complicated engineering. Here we suggest a simple, yet highly efficient, nanoscale white-light source based on a hybrid Si/Au nanoparticle with ultrabroadband (1.3-3.4 eV) spectral characteristics. We incorporate this novel source into a scanning-probe microscope and observe broadband spectrum of photoluminescence that allows fast mapping of local optical response of advanced nanophotonic structures with submicron resolution, thus realizing ultrabroadband near-field nanospectroscopy.