Antonio Alvaro Ranha Neves |
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Prof.
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Universidade Federal do ABC (UFABC)
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Center for Natural Sciences and Humanities
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Skills (4)
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17 Questions957 Followers
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7 Questions35 Followers
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34 Questions5049 Followers
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56 Questions12235 Followers
Research experience
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Jan 2008–
Dec 2012Research: Università del Salento
Università del SalentoLecce · Italy -
Jan 2006
Research: Universidade Estadual de Campinas
Universidade Estadual de CampinasCampinas · Brazil
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Apr 2009–
Mar 2012Research: Junior Research Fellow
CNR NANO - Istituto Nanoscienze Consiglio Nazionale delle Ricerche · National Nanotechnology LaboratoryItaly · Lecce -
Mar 2006–
Mar 2009Research: Postdoctoral Research Fellow
CNR NANO - Istituto Nanoscienze Consiglio Nazionale delle Ricerche · National Nanotechnology LaboratoryItaly · Lecce
Education
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Mar 2002–
Dec 2006Universidade Estadual de Campinas
Physics · DoctorateBrazil · Campinas -
Mar 1999–
Mar 2002Universidade Estadual de Campinas
Physics · MasterBrazil · Campinas -
Jun 1994–
Dec 1998Universidade de Brasília
Physics · BachelorBrazil · Brasilia
Other
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LanguagesEnglish, Portuguese, and Italian
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Scientific MembershipsOptical Society of America (OSA)
Brazilian Physics Scoeity (SBF) -
Journal RefereesOptics Letters, Optics Communications, Applied Optics, Optics Express, Journal of Applied Physics, Applied Physics Letters, Optics & Laser Technology, Optical Materials, Optics Commuications, Micron, Journal of Quantitative Spectroscopy and Radiative Transfer, Physica Scripta
Publications (30) View all
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Article: Effect of finite terms on the truncation error of Mie series.
Antonio Alvaro Ranha Neves, Dario Pisignano[show abstract] [hide abstract]
ABSTRACT: The finite sum of the squares of the Mie coefficients is very useful for addressing problems of classical light scattering. An approximate formula available in the literature, and still in use today, has been developed to determine a priori the number of the most significant terms needed to evaluate the scattering cross section. Here, we obtain an improved formula, which includes the number of terms needed for determining the scattering cross section within a prescribed relative error. This is accomplished using extended precision computation for a wide range of commonly used size parameters and indices of refraction. The revised formula for the finite number of terms can be a promising and valuable approach for efficient modeling light scattering phenomena.Optics Letters 06/2012; 37(12):2418-20. · 3.40 Impact Factor -
SourceAvailable from: Antonio Alvaro Ranha Neves
Article: Expansion of Arbitrary Electromagnetic Fields in Terms of Vector Spherical Wave Functions
[show abstract] [hide abstract]
ABSTRACT: Since 1908, when Mie reported analytical expressions for the fields scattered by a spherical particle upon incidence of an electromagnetic plane-wave, generalizing his analysis to the case of an arbitrary incident wave has proved elusive. This is due to the presence of certain radially-dependent terms in the equation for the beam-shape coefficients of the expansion of the electromagnetic fields in terms of vector spherical wave functions. Here we show for the first time how these terms can be canceled out, allowing analytical expressions for the beam shape coefficients to be found for a completely arbitrary incident field. We give several examples of how this new method, which is well suited to numerical calculation, can be used. Analytical expressions are found for Bessel beams and the modes of rectangular and cylindrical metallic waveguides. The results are highly relevant for speeding up calculation of the radiation forces acting on small spherical particles placed in an arbitrary electromagnetic field, for example in optical tweezers.03/2010; -
SourceAvailable from: Antonio Alvaro Ranha Neves
Article: Electromagnetic forces for an arbitrary optical trapping of a spherical dielectric
Antonio Alvaro Ranha Neves, Adriana Fontes, Liliana de Ysasa Pozzo, Andre Alexandre de Thomaz, Enver Chillce, Eugenio Rodriguez, Luiz Carlos Barbosa, Carlos Lenz Cesar[show abstract] [hide abstract]
ABSTRACT: Analytical solution for optical trapping force on a spherical dielectric particle for an arbitrary positioned focused beam is presented in a generalized Lorenz-Mie and vectorial diffraction theory. In this case the exact electromagnetic field is considered in the focal region. A double tweezers setup was employed to perform ultra sensitive force spectroscopy and observe the forces, demonstrating the selectively couple of the transverse electric (TE), transverse magnetic (TM) modes by means of the beam polarization and positioning, and to observe correspondent morphology-dependent resonances (MDR) as a change in the optical force. The theoretical prediction of the theory agrees well with the experimental results. The algorithm presented here can be easily extended to other beam geometries and scattering particles.11/2006; -
SourceAvailable from: Antonio Alvaro Ranha Neves
Article: Multi-photon in situ synthesis and patterning of polymer-embedded nanocrystals
Andrea Camposeo, Marco Polo, Antonio A. R. Neves, Despina Fragouli, Luana Persano, Sandra Molle, Anna M. Laera, Emanuela Piscopiello, Vincenzo Resta, Athanassia Athanassiou, Roberto Cingolani, Leander Tapfer, Dario Pisignano[show abstract] [hide abstract]
ABSTRACT: The in-situ synthesis and patterning of CdS nanocrystals in a polymer matrix is performed via multi-photon absorption. Quantum-sized CdS nanocrystals are obtained by irradiating a Cadmium thiolate precursor dispersed in a transparent polymer matrix with a focused near infrared femtosecond laser beam. High resolution transmission electron microscopy evidences the formation of nanocrystals with wurtzite crystalline phase. Fluorescent, nanocomposite patterns with sub-micron spatial resolution are fabricated by scanning the laser beam on the polymer/precursor composite. Moreover, the emission energy of the CdS nanocrystals can be tuned in the range 2.5-2.7 eV, by changing the laser fluences in the range 0.10-0.45 J cm-2. This method enables therefore the synthesis of luminescent, CdS-based composites to be used within patterned nanophotonic and light-emitting devices.Journal of Materials Chemistry 04/2012; · 5.97 Impact Factor -
SourceAvailable from: Antonio Alvaro Ranha Neves
Article: Laser emission from electrospun polymer nanofibers.
Andrea Camposeo, Francesca Di Benedetto, Ripalta Stabile, Antonio A R Neves, Roberto Cingolani, Dario PisignanoSmall 03/2009; 5(5):562-6. · 8.35 Impact Factor