Composite grating of Nitrogen-vacancy (N-V) centers nanodiamond (ND) is fabricated using soft lithography. Wide distribution with enhanced radiated powers from NDs is observed using confocal measurements. Numerical simulations reveal that this distribution arises from random emitting dipoles orientations inside the ND.
Spontaneous emission (SE) of nitrogen-vacancy centers (NV-centers), which are contained in a single nanodiamond (ND), placed near a silver nanocube, is investigated both experimentally and theoretically. The ND-cube system is assembled with an atomic force microscope, allowing us to directly compare its SE properties to that of the isolated ND. It is demonstrated that the cube coupled NV-centers exhibit strongly polarized SE. For optimal pump laser polarization, the rate of photons is enhanced by a factor of 4.1, with the excited state lifetime being reduced by a factor of 4.1. The enhancement of photon rate is a consequence of local field enhancement of the pump laser, while the SE polarization and lifetime reduction results from coupling of NV-centers to the localized surface plasmon mode of the nanocube. The experimental observations are in qualitative agreement with the model of SE from randomly oriented electric dipoles, allowing us to reveal the underlying physics of the investigated configuration.
Nitrogen-vacancy centers (NVs) are an atomic defect in diamond which possess remarkable fluorescence and spin properties which can be used for multiple metrological applications, particularly when the NV is hosted in nanodiamond, which can be easily integrated with a variety of nanoscale systems. A new class of nanodiamond hybrid nanostructures was developed using bottom-up synthesis methods. In this work, coupling between NV centers and plasmonic, excitonic and magnetic nanoparticles in these nanodiamond hybrid nanostructures is investigated using fluorescence lifetime measurements, spin relaxometry measurements and modeled using finite element method (FEM) and Monte Carlo simulations. This work not only characterizes the properties of these nanodiamond-hybrid nanostructures but also facilitates design guidelines for future hybrid structures with enhanced metrological and imaging capabilities.
We investigated the suitability of nanodiamonds (NDs) with nitrogen-vacancy (NV) centres as samples for resolution tests in stimulated emission depletion (STED) microscopy. The nanodiamonds were prepared using three different methods including additional proton irradiation to enhance NV centre density. This high-density sample exhibited stronger photoluminescence intensity, greater fluorescence stability, and higher image contrast under STED conditions. All samples showed strong resistance to damage from high STED laser power. Our results highlight the robustness and effectiveness of NDs with NV centres as reliable standards for evaluating STED microscope resolution.
Abstract We report on the characterization of the angular-dependent emission of single-photon emitters based on single nitrogen-vacancy (NV-) centers in nanodiamond at room temperature. A theoretical model for the calculation of the angular emission patterns of such an NV-center at a dielectric interface will be presented. For the first time, the orientation of the NV-centers in nanodiamond was determined from back focal plane images of NV-centers and by comparison of the theoretical and experimental angular emission pattern. Furthermore, the orientation of the NV-centers was also obtained from measurements of the fluorescence intensity in dependence on the polarization angle of the linearly polarized excitation laser. The results of these measurements are in good agreement. Moreover, the collection efficiency in this setup was calculated to be higher than 80% using the model of the angular emission of the NV-centers.
We experimentally demonstrate the integration of silicon-vacancy centers in nanodiamonds (SiV-NDs) with an optical nanofiber (ONF). We grow SiV-NDs on seed NDs dispersed on a quartz substrate using a microwave plasma-assisted chemical vapor deposition method. First, we search and characterize SiV-NDs on a quartz substrate using an inverted confocal microscope and an atomic force microscope (AFM). Subsequently, we pick up SiV-NDs from the quartz substrate and deposit them on the surface of a free-standing ONF using the AFM tip. The fluorescence emission spectrum, photon count rate, and intensity correlations for SiV-NDs are systematically measured.