Resonant high-refractive-index nanoparticles and nanostructures represent a promising platform for effective light manipulation at nanoscale and pave the way for creation of novel photonic devices. Interaction of a quantum emitter with one or several dielectric particles allows to significantly alter its radiation pattern and spontaneous emission rate [1]. Diamond particles containing colour centers such as nitrogen-vacancy, silicon-related and nickel-related centers [2] are of special interest in this context. They can be viewed as a single photonic nanodevice with emitting source embedded inside а diamond particle. Indeed, relatively high refractive index (n~2.4) of the diamond and almost zero absorption in visible region make it possible to exploit the morphology- and size-dependent resonance properties of the diamond particles to control the emission properties of luminescent centers [3].
Here, we study the properties of luminescent diamond particles of different sizes (up to 1 um) containing multiple NV-centers. NV-centers were incorporated into the sample during the growing of diamond film by plasma-enhanced chemically vapor deposition method. After milling the fabricated film the obtained diamond particles were characterized by dark-field spectroscopy method. In luminescence experiments, NV-centers were non-resonantly excited with 532 nm laser and the lifetime measurements of the excited state were carried out by the time-correlated single photon counting method.
We compare the luminescence properties of the diamond particles that exhibit resonances in the spectral region of NV-center luminescence. Fig.1 demonstrates the dark-field scattering spectra, photoluminescence intensity spectra and the time dependencies of the luminescence signal for these two cases. We observe that the spectral position of the resonance of diamond particle has a direct influence on the lifetime at zero-phonon line providing lifetime reduction in the resonant case by 1.5 times as compared to non-resonant one.
[1] A.I. Kuznetsov et.al, "Optically resonant dielectric nanostructures", Science, v.354, p.aag2472, 2016.
[2] I. Aharonovich, "Diamond photonics", Nat. Photon., v.5, 397, p.2011.
[3] D.A. Shilkin et.al., "Optical magnetism and fundamental modes of nanodiamonds", ACS Photon., v.4, p.1153, 2017.
Optical properties of nanostructures , Quantum dots and colour centres
