Publications

2017
Devlin, R.C., Ambrosio, A., Rubin, N.A., Mueller, J.P.B. & Capasso, F. Arbitrary spin-to-orbital angular momentum conversion of light. Science 358, 896-901 (2017). Publisher's VersionAbstract

Optical elements that convert the spin angular momentum (SAM) of light into vortex beams have found applications in classical and quantum optics. These elementsSAM-toorbital angular momentum (OAM) convertersare based on the geometric phase and only permit the conversion of left- and right-circular polarizations (spin states) into states with opposite OAM. We present a method for converting arbitrary SAM states into total angular momentum states characterized by a superposition of independent OAM. We designed a metasurface that converts left- and right-circular polarizations into states with independent values of OAM and designed another device that performs this operation
for elliptically polarized states. These results illustrate a general material-mediated connection between SAM and OAM of light and may find applications in producing complex structured light and in optical communication.

Ambrosio, A., et al. Mechanical Detection and Imaging of Hyperbolic Phonon Polaritons in Hexagonal Boron Nitride. ACS Nano 11, 9, 8741-8746 (2017). Publisher's Version
Oscurato, S.L., Borbone, F., Maddalena, P. & Ambrosio, A. Light-Driven Wettability Tailoring of Azopolymer Surfaces with Reconfigured Three-Dimensional Posts. ACS Applied Materials & Interfaces 9, 35, 30133-30142 (2017). Publisher's VersionAbstract
The directional light-induced mass migration phenomenon arising in the photoresponsive azobenzene-containing materials has become an increasingly used approach for the fabrication of controlled tridimensional superficial textures. In the present work we demonstrate the tailoring of the superficial wettability of an azopolymer by means of the light-driven reconfiguration of an array of imprinted micropillars. Few simple illumination parameters are controlled to induce nontrivial wetting effects. Wetting anisotropy with controlled directionality, unidirectional spreading, and even polarization-intensity driven two-dimensional paths for wetting anisotropy are obtained starting from a single pristine pillar geometry. The obtained results prove that the versatility of the light-reconfiguration process, together with the possibility of reversible reshaping at reduced costs, represents a valid approach for both applications and fundamental studies in the field of geometry-based wettability of solid surfaces.
Schöche, S., et al. Optical properties of graphene oxide and reduced graphene oxide determined by spectroscopic ellipsometry. Applied Surface Science 421, Part B, 778 - 782 (2017). Publisher's Version
Longo, A., et al. Graphene oxide prepared by graphene nanoplatelets and reduced by laser treatment. Nanotechnology 28, 22, 224002 (2017). Publisher's Version
Oscurato, S.L., et al. New microscopy technique based on position localization of scattering particles. Opt. Express 25, 10, 11530–11549 (2017). Publisher's VersionAbstract
We introduce the Holographic &\#x2013; Single Scatterer Localization Microscopy in which we combine dynamical laser speckle illumination with centroid localization of backscattered light spots in order to localize isolated scattering particles. The reconstructed centroid images show very accurate particle localization, with precision much better than the width of diffraction-limited image of the particles recorded by the CCD. Furthermore, the method provides an improved resolution in distinguishing two very close scattering objects compared to the standard laser scanning techniques and can be assimilated to a confocal technique in the ability of light background rejection in three-dimensional disposition of scattering objects. The illumination is controlled via a digital holography setup based on the use of a spatial light modulator. This allows not only a high level of versatility in the illumination patterns, but also the remarkable characteristics of absence of moving mechanical parts, typical of the laser scanning techniques, and the possibility of strongly miniaturizing the setup.
Ambrosio, A., Devlin, R.C., Capasso, F. & Wilson, W.L. Observation of Nanoscale Refractive Index Contrast via Photoinduced Force Microscopy. ACS Photonics 4, 846-851 (2017). Publisher's Version
Devlin, R.C., et al. Spin-to-orbital angular momentum conversion in dielectric metasurfaces. Optics Express 25, 1, 377-393 (2017). Publisher's Version
Wintz, D., Ambrosio, A., Zhu, A.Y., Genevet, P. & Capasso, F. Anisotropic Surface Plasmon Polariton Generation Using Bimodal V-Antenna Based Metastructures. ACS Photonics 4, 1, 22-27 (2017). Publisher's Version
2016
Della Ventura, B., et al. A simple and flexible model for laser-driven antibody-gold surface interactions: functionalization and sensing. ACS Applied Materials & Interfaces 8, 21762-21769 (2016).
Wintz, D., et al. Optical characterization of van der Waals materials via near-field microscopy. CLEO: Science and Innovations SW1R–2 (2016).
Zhu, A.Y., Wintz, D., Ambrosio, A., Genevet, P. & others, Asymmetric surface plasmon wake generation with a meta-structure. CLEO: QELS\_Fundamental Science FM3N–4 (2016).
Ambrosio, A., et al. Polarization-switchable visible vortex beams from a dielectric metasurface. CLEO: QELS\_Fundamental Science FM2D–2 (2016).
Devlin, R.C., et al. Spin-to-orbital angular momentum conversion in dielectric metasurfaces. arXiv preprint arXiv:1605.03899 (2016).
Khorasaninejad, M., Ambrosio, A., Kanhaiya, P. & Capasso, F. Broadband and chiral binary dielectric meta-holograms. Science Advances 2, 5, e1501258 (2016).
2015
Capasso, F., Wintz, D., Genevet, P., Ambrosio, A. & Woolf, A. Metagratings for tunable unidirectional steering and focusing of surface plasmons (Presentation Recording). SPIE Nanoscience+ Engineering 95442E–95442E (2015).
Aramo, C., et al. Observation of a photoinduced, resonant tunneling effect in a carbon nanotube–silicon heterojunction. Beilstein journal of nanotechnology 6, 1, 704-710 (2015).
Ambrosio, A., Wintz, D., Genevet, P. & Capasso, F. Controlled steering and focusing of Surface Plasmons with Metasurfaces. 2015 IEEE Photonics Conference (IPC) 460–461 (2015).
Valentini, A., et al. A conductive surface coating for Si-CNT radiation detectors. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 790, 14–18 (2015).

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