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Article
Search for long distance correlations between extensive air showers detected by the EEE network
A search for long distance correlations between individual Extensive Air Showers (EAS) detected by pairs of MRPC telescopes of the Extreme Energy Events (EEE) network was carried out. The search for an anomaly...
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Article
Looking at the sub-TeV sky with cosmic muons detected in the EEE MRPC telescopes
Distributions of secondary cosmic muons were measured by the Multigap Resistive Plate Chambers (MRPC) telescopes of the Extreme Energy Events (EEE) Project, spanning a large angular and temporal acceptance thr...
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Article
Glass-ceramics: A class of nanostructured materials for photonics
Glass-ceramics (GCs) are constituted by nanometer-to-micron-sized crystals embedded in a glass matrix; usually, their structural or functional elements (clusters, crystallites or molecules) have dimensions in ...
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Article
Open AccessSol–gel-derived photonic structures handling erbium ions luminescence
The sol–gel technique is a very flexible, relatively simple, and low-cost method to fabricate many different innovative photonic structures characterized by specific functionalities. During synthesis, starting...
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Chapter and Conference Paper
Whispering Gallery Modes Microresonators for Sensing and Biosensing Applications
Whispering Gallery Modes (WGMs) microresonators continue to receive an even greater interest for investigation in many fundamental processes (e.g.: quantum electrodynamics or non–linear optics) and in more app...
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Article
Whispering gallery mode profiles in a coated microsphere
The properties of whispering gallery modes (WGM) of a microsphere can be tailored by coating the resonator with a thin film. If the coating has a higher refractive index than the microsphere core, the resultin...
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Article
Cosmic rays Monte Carlo simulations for the Extreme Energy Events Project
The Extreme Energy Events Project (EEE Project) is an innovative experiment to study very high energy cosmic rays by means of the detection of the associated air shower muon component. It consists of a network...
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Chapter and Conference Paper
Optical Microbubble Resonator: A Novel Structure for Sensing Applications
Recently a new class of optical resonant microcavities, the so called microbubble resonators (MBRs) for their particular shape, have been demonstrated. Their feature of combining the unique properties of whisp...
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Article
Time correlation measurements from extensive air showers detected by the EEE telescopes
Time correlated events due to cosmic muons from extensive air showers have been detected by means of telescope pairs of the EEE (Extreme Energy Events) Project array. The coincidence rate, properly normalized ...
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Article
The EEE experiment project: status and first physics results
The Extreme Energy Events Project is an experiment for the detection of Extensive Air Showers which exploits the Multigap Resistive Plate Chamber technology. At the moment 40 EEE muon telescopes, distributed a...
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Article
Whispering gallery mode microresonators: Fundamentals and applications
Confinement of light into small volumes has become an essential requirement for photonic devices; examples of this trend are provided by optical fibers, integrated optical circuits, semiconductor lasers, and p...
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Article
Reproducibility of splicer-based long-period fiber gratings for gain equalization
We fabricated long-period fiber gratings (LPFGs) using electric arc discharges. We observed that the fiber becomes slightly tapered due to longitudinal tension during the arc: this effect depends on the arc cu...
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Article
Er3+-activated silica inverse opals synthesized by the solgel method
We present the details of the sol-gel processing used to realize inverse silica opal, where the silica was activated with 0.3 mol% of Er3+ ions. The template (direct opal) was obtained assembling polystyrene sphe...
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Article
Diagnostic techniques for photonic materials based on Raman and Brillouin spectroscopies
The elastic and vibrational properties of a material, bulk or planar waveguide, are studied by Brillouin and Raman spectroscopy to follow the process of nanocrystals growth in glass-ceramics. The nanoparticles...
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Article
Assessment of nanocomposite photonic systems with the X-ray photoelectron spectroscopy
The chemical compositions of Ag-Er co-doped phosphate and silicate glasses were investigated with X-ray photoelectron spectroscopy with the purpose to identify the chemical state of silver. The analysis of the...
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Article
Effect of Yb3+ concentration on Er3+ luminescence properties of sol-gelderived silica-alumina xerogels
Er3+ / Yb3+ co-doped silica-alumina monolithic xerogels were prepared with the same concentration on 2 000 Er/Si ppm and 6 000 Al/Si ppm. The Yb/Si content was varied from 0 to 4 000 ppm Densification of the samp...
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Article
Photoluminescence of rare-earth—doped glasses
Rare-earth elements are of interest in several high-tech and environmental application areas, the two major ones concerning magnetic and optical devices. In the latter field, one can exploit the unique photolu...
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Article
Photoluminescence Spectroscopy of Er3+/Yb3+ Co-Activated Silica-Alumina Monolithic Xerogels
Two Er3+/Yb3+ monolithic silica-alumina xerogels doped with different Yb3+ concentrations were prepared by sol–gel route. The samples were thermally treated in air at 950°C for 120 h, and Raman and UV-visible-NIR...
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Article
Erbium-Activated Silica-Titania Planar Waveguides
(100 − x)SiO2-(x)TiO2-ErO3/2 planar waveguides, with 7 ≤ x ≤ 20 have been prepared by sol-gel route using the dip-coating technique. The thickness of the films was optimized to support a single propagating mode a...
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Article
Er3+/Yb3+ Co-Activated Silica-Alumina Monolithic Xerogels
Monolithic silica xerogels doped with different concentrations of Er3+, Yb3+ and Al3+ were prepared by sol-gel route. Densification was achieved by thermal treatment in air at 950°C for 120 h with a heating rate ...
