"Single-photon emitters in lead-implanted single-crystal diamond", S. Ditalia Tchernij et al., ACS Photonics 5 (12), 4864-4871 (2018)
UniTo and INRiM partners identified and characterized for the first time a new class of optically active defects in diamond based on Pb impurities. In consideration of their promising photo-physical properties, these defects disclose appealing perspectives in quantum-enhanced imaging. In the figure: journal cover dedicated to the report.
"Mapping the local spatial charge in defective diamond by means of NV sensors – A “self-diagnostic” concept", J. Forneris et al., Phys. Rev. Appl. 10, 014024 (2018)
UniTo and INRiM partners developed a imaging methodology the allows the high-spatial-resolution mapping of local electrical fields developed in defective diamond devices as a consequence of locally trapped charges. The technique is based on a "self-diagnostic" concept, i.e. the same defects which are responsibile for charge trapping can detect the space-charge-induced local electrical fields via the optica detection of their spin resonances. In the figure: optically-acquired electric-field map (top) and relevant numerical simulation (bottom).
"Quantum micro-nano devices fabricated in diamond by femtosecond laser and ion irradiation", S. M. Eaton et al., Adv. Quantum Technologies 2, 1900006 (2019)
UniTo partners contributed to a state-of-the-art review of current laser- and ion-beam-based technique for the fabrication of diamond-based quantum devices. In particular, the article features a review of the engineering of the most widely employed classes of optically active defects in diamond for applications in quantum imaging and quantum sensing. In the figure: journal back cover dedicated to the report.
"Inverted plasmonic lens design for nanometrology applications", T Käseberg et al, Meas. Sci. Technol.31 074013 (2020)
Planar plasmonic lenses have attracted a great deal of interest over the last few years for their super-resolution focusing capabilites. These highly compact structures with dimensions of only a few micrometres allow for the focusing of light to sub-wavelength-sized spots with focal lengths reaching into the far-field. This offers opportunities for new methods in nanometrology; for example, applications in microscopic Mueller matrix ellipsometry setups. However, the conventional plasmonic lens is challenging to fabricate. We present a new design for plasmonic lenses, which is called the inverted plasmonic lens, to accommodate the lithographic fabrication process. In this contribution, we used numerical simulations based on the finite element method in combination with particle swarm optimization to determine ideal parameter ranges and tolerances for the design of inverted plasmonic lenses for different wavelengths in the visible and near-infrared domain and focal lengths between 5 µm and 1 mm.
"Superresolution effect due to a thin dielectric slab for imaging with radially polarized light", P. Meng, S. F. Pereira, Xiujie Dou, and H. P. Urbach, Opt. Expr. 28, 20660 (2020)
We propose a imaging system illuminated with radially polarized light combined with a suitable substrate that contains a thin dielectric layer to demonstrate that the imaging quality can be enhanced. The coupling between the evanescent wave produced in a designed thin dielectric layer, the small particles and the propagating wave forms a mechanism to transfer sub-wavelength information about the particles to the far field.
"Hong-Ou-Mandel interferometry on a biphoton beat note", Chen, Y., Fink, M., Steinlechner, F. et al., NPJ Quantum Inf. 5, 43 (2019)
By using frequency entanglement in combination with a HOM configuration a temporal sensitivity of 9 as has been demonstrated, which corresponds to a longitudinal sensitivity of 2.7 nm2.7 nm. Only two frequencies well separated has been considered, instead of a large bandwidth signal of some hundreds of nanometres.