Papers by Fernando Moreno
UV Plasmonic Behavior of Various Metal Nanoparticles in the Near- and Far-Field Regimes: Geometry and Substrate Effects
The Journal of Physical Chemistry C, 2013
ABSTRACT The practical efficacy of technologically promising metals for use in ultraviolet plasmo... more ABSTRACT The practical efficacy of technologically promising metals for use in ultraviolet plasmonics (3–6 eV) is assessed by an exhaustive numerical analysis. This begins with estimates of the near- and far-field electromagnetic enhancement factors of isolated hemispherical and spherical metallic nanoparticles deposited on typical dielectric substrates like sapphire, from which the potential of each metal for plasmonic applications may be ascertained. The ultraviolet plasmonic behavior of aluminum, chromium, copper, gallium, indium, magnesium, palladium, platinum, rhodium, ruthenium, titanium, and tungsten was compared with the well-known behavior of gold and silver in the visible. After exploring this behavior for each metal as a function of nanoparticle shape and size, the deleterious effect caused by the metal’s native oxide is considered, and the potential for applications such as surface-enhanced Raman spectroscopy, accelerated photodegradation and photocatalysis is addressed.
Nano letters, Mar 14, 2018
In plasmon-enhanced heterogeneous catalysis, illumination accelerates reaction rates by generatin... more In plasmon-enhanced heterogeneous catalysis, illumination accelerates reaction rates by generating hot carriers and hot surfaces in the constituent nanostructured metals. In order to understand how photogenerated carriers enhance the nonthermal reaction rate, the effects of photothermal heating and thermal gradients in the catalyst bed must be confidently and quantitatively characterized. This is a challenging task considering the conflating effects of light absorption, heat transport, and reaction energetics. Here, we introduce a methodology to distinguish the thermal and nonthermal contributions from plasmon-enhanced catalysts, demonstrated by illuminated rhodium nanoparticles on oxide supports to catalyze the COmethanation reaction. By simultaneously measuring the total reaction rate and the temperature gradient of the catalyst bed, the effective thermal reaction rate may be extracted. The residual nonthermal rate of the plasmon-enhanced reaction is found to grow with a superline...
Backscatter
Encyclopedia of Optical and Photonic Engineering, Second Edition, 2016
Research in Optical Sciences, 2014
Electromagnetic enhancement of metallic nanoparticles on substrates is assessed by an exhaustive ... more Electromagnetic enhancement of metallic nanoparticles on substrates is assessed by an exhaustive numerical analysis. The potential of each technologically promising metal for UVplasmonic applications may be ascertained.
Nature communications, Jan 4, 2017
Sub-wavelength particles made from high-index dielectrics, either individual or as ensembles, are... more Sub-wavelength particles made from high-index dielectrics, either individual or as ensembles, are ideal candidates for multifunctional elements in optical devices. Their directionality effects are traditionally analysed through forward and backward measurements, even if these directions are not convenient for in-plane scattering practical purposes. Here we present unambiguous experimental evidence in the microwave range that for a dimer of HRI spherical particles, a perfect switching effect is observed out of those directions as a consequence of the mutual particle electric/magnetic interaction. The binary state depends on the excitation polarization. Its analysis is performed through the linear polarization degree of scattered radiation at a detection direction perpendicular to the incident direction: the beam-splitter configuration. The scaling property of Maxwell's equations allows the generalization of our results to other frequency ranges and dimension scales, for instance,...
Multiple scattering and enhanced backscattering effects for flat substrates with small protuberances
A low cost photon statistics tecnique in laser Doppler velocimetry
Optica Pura y Aplicada
Transform methods applied to experiments of single photon decay spectroscopy
Light Scattering by Particles on Substrates. Theory and Experiments
During recent decades the study of the scattering of electromagnetic waves by rough surfaces has ... more During recent decades the study of the scattering of electromagnetic waves by rough surfaces has aroused the interest of many research groups and has been approached from different standpoints. Of the geometrical models developed either to reproduce experimental results or to understand the physics involved in the phenomena of scattering, particular mention should be made of the model consisting of ensembles of particles with simple geometry seeded onto flat surfaces. What makes these surfaces especially attractive is that they allow both controlled calculation for different sizes, shapes, densities, or optical properties, and the possibility of experimental testing of such systems. But these surfaces are also interesting for other reasons in certain specific areas, such as mirror degradation by particle contamination,1 detection of surface defects in the semiconductor industry,2 construction of biosensors,3 optical particle sizing,4 and near field optics.5
Dispositivo y método para la detección de biomarcadores
Improvement in laser Doppler velocimetry by the use of time-interval photon statistics
Physical Review A, 1986
ABSTRACT
Dielectric gap-nanoantennas as building blocks for magnetic dipolar emission
Advances in Imaging, 2009
We present a numerical study of the spectral variations of localized surface plasmon resonances (... more We present a numerical study of the spectral variations of localized surface plasmon resonances (LSPR) in a 3D-probe metallic nanoparticle scanned over an inhomoegeneous dielectric surface. The possibilities for both, index monitoring and lateral resolution at nanoscale level are explored, with special attention paid to the shape of the probe and the profile of the near field underneath.
Journal of the Optical Society of America, 1981
The effect of intracavity wavelength selectors on the position of tunable laser modes has been ev... more The effect of intracavity wavelength selectors on the position of tunable laser modes has been evaluated in the case of short light pulses propagating into the resonator. The narrow-peak approximation is analyzed for the calculus of extra phase introduced by an intracavity selector. A method also has been derived for the calculation of extra phase for a general-shape pulse f(y). In particular, the latter method is applied for a Gaussian-shape pulse.
<title>Analysis of multiexponential decays through a sine transform method in single-photon decay spectroscopy experiments</title>
Time-Resolved Laser Spectroscopy in Biochemistry II, 1990
ABSTRACT
Resonances in Light Scattering by Small Magnetic Particles
Photonic Metamaterials: From Random to Periodic, 2006
ABSTRACT Light scattering resonances in small particles are analyzed either exactly or by approxi... more ABSTRACT Light scattering resonances in small particles are analyzed either exactly or by approximate expressions for the most important Mie coefficients. Materials with different optical properties, incluiding Double Negative (as corresponding to LHM), are considered.
8th Conference on Electromagnetic and Light Scattering by Nonspherical Particles: Theory, Measurements and Applications
Optical backscattering measurements from fractal surfaces and their possible relevance to radar scattering from the sea surface
Waves in Random Media, 1992
ABSTRACT
Plasmon-Enhanced Fluorescence and Spectral Modification in SHINEF
The Journal of Physical Chemistry C, 2011
... Ricardo F. Aroca*, Geok Yi Teo, Haider Mohan, Ariel R. Guerrero, Pablo Albella, and Fern... more ... Ricardo F. Aroca*, Geok Yi Teo, Haider Mohan, Ariel R. Guerrero, Pablo Albella, and Fernando Moreno§. Department of Chemistry and Biochemistry. Faculty ... 13. Grabar, KC; Freeman, RG; Hommer, MB; Natan, MJ Anal. Chem. ...
Application of a sine transform method to experiments of single-photon-decay spectroscopy: Single exponential decay signals
Review of Scientific Instruments, 1992
In this article we present as an experiment in single-photon-decay spectroscopy an alternative me... more In this article we present as an experiment in single-photon-decay spectroscopy an alternative method to that based on the measurement of the probability distribution function, Pf(t), of the time intervals for the time of arrival of the first photon after the excitation pulse. We propose the measurement of the sine transform of Pf(t), which gives a maximum when the fluorescence signal is of the single exponential decay type. The existence of this maximum allows us to determine very accurately the value of the decay constant using a number of measurements which is lower than that required to establish a Pf(t) that is accurate enough to draw the same conclusions. A theoretical model of the error is studied and is compared by means of a computer simulation with the usual method of measuring Pf(t). An experiment is performed using a TMMC crystal to verify the validity of the theoretical predictions and of the simulation results.
Uploads
Papers by Fernando Moreno