2014 Fall Meeting
ADVANCED FUNCTIONAL MATERIALSP
Advances on functional doped glasses: technologies, properties and applications
Doped glasses exhibit unique properties for a wide range of applications, ranging from optoelectronics and photonics to systems for energy and environment. The production and the characterization of these materials are key factors for the design of new devices contributing to the advancement of material science and technology.
Glass doping allows the production of unique functional materials which are nowadays used for a huge amount of applications. Processing techniques are very different, like ion exchange, ion implantation, sol-gel synthesis, glass melting, etc. The kind of produced doped glasses range from rare earth and transition metal ion containing glasses to nanostructured systems with metal or oxide nanoparticles. Applications can also range from photonics, optoelectronics for communication networks, optical amplifiers, sensors, smart windows, memory storage systems, to intelligent glasses with peculiar mechanical properties.
The control of the production procedures coupled with accurate characterizations, modeling and theoretical understanding of the resulting materials are key factors for the development and the improvement of the performances of these systems. In this field, a great amount of work is still being carried on by several research groups, as testified by the works presented at international congresses like "International Conference on the Structure of Non-Crystalline Materials (NCM12)", held every year (last in 2013) and "SiO2 and Advanced Dielectrics", which is held every two years (next in 2014). Moreover, in 2007, a symposium of the E-MRS Fall Meeting was dedicated to ion exchange in glass, attracting several scientists.
The aim of this symposium is to provide a forum for scientists working on different areas of synthesis, processing, characterization and device integration of doped glasses, including students and people involved in companies that develop new processes and materials. The exchange of ideas on the design and the characterization of doped glass systems will allow both to improve the processes for the production of functional doped glasses suitable for high performance devices and to create research networks between scientists coming from different areas and countries.
Hot topics to be covered by the symposium
- Synthesis, processing and characterization of doped glasses.
o Ion exchange and ion diffusion for glass doping.
o Ion implantation and irradiation.
o Sol gel synthesis of doped glasses.
o Nanostructured doped glasses.
o Rare earth and transition metal doped glasses.
o Doped chalcogenide glasses.
- Advances on applications of doped glasses
o Doped glasses photonics and optoelectronics.
o Doped glasses for sensors.
o Doped glasses for solar energy conversion.
o Doped glasses with smart mechanical properties.
List of invited speakers
- Miguel Angel Garcia (ICV – Madrid, Spain): Plasmonic and magnetic nanoparticles in glass.
- Francesco Gonella (Ca’ Foscari – Venice, Italy): Solid state procedures for glass doping.
- Jean-Luc Adam (Institut des sciences chimiques de Rennes, France): Rare-earth-doped chalcogenide glasses.
- Klaus Rademann (Humboldt-Universität Berlin, Germany): Silver and gold interfaces with glass: luminescence and recuperation devices.
- Anna Lukowiak (Wroclaw Academy of Sciences, Poland): Sol–gel as a useful technique for fabrication of erbium-activated photonic structures
- Andrei Lipovskii (St.-Petersburg Academic University, Russia):Nanostructured glasses for optoelectronics.
- Jean-Emmanuel Broquin (IMEP-LAHC – University of Grenoble, France):Optoelectronic devices by ion exchange.
- Miguel Jiménez de Castro (IO-CSIC –Madrid, Spain): Bi nanoparticles in alumina thin films and bulk germanate glasses.
- Anna Vedda (Università Milano-Bicocca, Italy): Scintillating fibers for in-vivo radiation dosimetry
- Seppo Honkanen (University of Eastern Finland): Ag nanoparticles in glass for SERS.
- Rui M. Almeida (Instituto Superior Técnico Rovisco Pais, Portugal): Rare-earth doped up-conversion coatings for solar cell applications.
- Animesh Jha (University of Leeds): Advanced Rare-earth doped glasses for thin film devices.
- Chiara Maurizio (University of Padova): Nucleation mechanisms in doped glasses analyzed by X-Ray absorption spectroscopy.
Tentative list of scientific committee members
- Paolo Mazzoldi (University of Padua, Italy)
- Giancarlo Righini (CNR-IFAC - Firenze, Italy)
- Maurizio Ferrari (CNR-IFN Trento, Italy)
- Stefano Pelli (CNR-IFAC - Firenze, taly)
- Gino Mariotto (University of Verona, Italy)
- Elise Ghibaudo (IMEP-LAHC - University of Grenoble, France)
- Alicia Duran (ICV - Madrid, Spain)
- Elti Cattaruzza (Ca' Foscari University - Venice, Italy)
- Michel Mortier (CNRS-ENSCP Paris, France)
- Angela Seddon (University of Nottingham, UK)
- Rolindes Balda (CSIC-UPV Bilbao, Spain)
- Marian Marciniak (NIT Warsaw, Poland)
- Dominik Dorosz (Bialystok University of Technology, Poland)
A selected number of peer-reviewed papers will be sent for publication to Ceramics International.
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Authors : C. Maurizio
Affiliations : Physics and Astronomy Department, University of Padova, via Marzolo 8, 35131 Padova, Italy
Resume : Heterogeneous nucleation phenomena are interesting in themselves and strategic for technological applications of nanoaggregate-doped materials. Controlling in detail the nucleation and growth of clusters in a matrix is fundamental to tailor the cluster size distribution that, often together with the cluster-matrix interaction, determines the macroscopic and technologically relevant properties of nanocomposites. Experiments on metal nucleation in a matrix are tough, due to metal dilution and to the very small radius of the smallest stable aggregates, typically of few tenths of nanometer. Advanced synchrotron-based characterizations, as X-ray absorption spectroscopy and high-resolution x-ray fluorescence emission allow getting structural information on the local site of the metal species detecting few-atoms aggregates as well as on dispersed metal fraction. The talk focuses on the experimental investigation, based on x-ray absorption spectroscopies, on the very early steps of metal clusterization in doped glasses, as induced by the doping process itself (ion implantation, ion exchange) and/or intentionally promoted by specific annealing treatments. The optical properties are correlated with the structure of the composite at the atomic level. It is shown how the photoluminescence from very small metal aggregates in glass depends not only on the cluster size but also on the cluster-matrix interaction. This has relevant consequences on the cluster emission in the visible-infrared range and, for metallic clusters embedded into rare-earth doped glasses, on the cluster to rare-earth energy transfer, crucial to enhance the rare-earth emission intensity.
Authors : M .A. Garcia()1, A. Serrano(1) and O. Rodríguez de la Fuente(2)
Affiliations : (1) Institute for Ceramics and Glass- CSIC (2) Dpt. of Materials Physics - University Complutense at Madrid
Resume : The incorporation of functional nanoparticles onto glass surfaces results appealing for both, improving the properties of the glass and to develop new ones. A very interesting method to cover large glass areas with nanoparticles consists in thin film deposition and subsequent annealing. This method has been applied to coat glasses with gold nanoparticles that exhibit surface plasmon resonance. The stress relief after the thermal annealing, due to the difference of thermal expansion coefficient between the metal and the substrate, promotes hillock formation and subsequent hole nucleation, growth and percolation, leading to the formation of layers of nanoparticles. The nanoparticle size and inter-particle distance can be tuned by controlling the initial film thickness and the annealing time, temperature and atmosphere, providing a simple and low cost method to prepare NPs layers over large areas. It is possible to obtain also iron oxide nanoparticles by the same route. In this case Fe films are deposited on the glass and annealed in air. The oxidation of the Fe during the annealing yield an increase of volume that results in stresses that induces nanoparticle formation. Finally, we recently demonstrated that the method can be applied to obtain complex nanoparticles by deposition and annealing of Au-Fe multilayers. These complex nanoparticles combine plasmonic and magnetic properties that can be tuned through the processing parameters.
Authors : S. A. Salehizadeh; J. Zavanik; M. P. F. Graça; M. A. Valente;
Affiliations : I3N - Department of Physics, University of Aveiro, Campus Santiago, 3810-193 Aveiro, Portugal; Center for Electron Microscopy and Microanalysis , Joef Stefan Institute, Ljubljana, Slovenia; I3N - Department of Physics, University of Aveiro, Campus Santiago, 3810-193 Aveiro, Portugal; I3N - Department of Physics, University of Aveiro, Campus Santiago, 3810-193 Aveiro, Portugal
Resume : The sol-gel process is a very flexible route for producing sieving matrix such as SiO2 with pores radii in nano scale. Due to significant interest for biomedical application, the magnetic bioactive SiO2 glass, doped with Fe2O3, was prepared by the solgel method. The effect of Fe/Si molar ratio and heat treatment time were investigated. The dried gels with x = 2 and 10 mol % were heat-treated (HT) in air, at 1000 oC for 4, 12 and 24 hours. The obtained glasses and glassceramics were studied by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and magnetic measurements. The X-ray diffraction patterns show that the addition of Fe2O3 and the HT duration can lead to the growth of iron oxide and SiO2 crystalline phases with different sizes. From the TEM micrographs, it can be observed, in the samples with 2 mol %, HT during 4 and 12 hours, the formation of spherical particles with a diameter < 10 nm. For the sample with 2 mole % HT at 24 h, SEM micrographs display particles with sizes in the range of 10 nm up to 50 nm. These particles tend to agglomerate in bigger particles as observed by SEM. The average particle size increases drastically up to 200 nm as the amount of Fe2O3 rises to 10 mol % and the HT duration reaches to 24 hours. In agreement with the morphological analysis, the magnetic measurement depicts that the samples with 2 mol % HT at 4 and 12 hours have a superparamagnetic behavior, while for the sample HT at 24 hours and for the HT samples with 10Fe2O3-90SiO2 compositions, weak and strong ferromagnetic characteristics, are observed, respectively. This evolution from superparamagnetism to ferromagnetism can be attributed to a structural transformation and magnetic interactions within the iron nanoparticles.
Authors : Mark Buckwell, Luca Montesi, Adnan Mehonic, Manveer Munde, Stephen Hudziak, Sarah Fearn, Richard Chater, David McPhail, Anthony J. Kenyon
Affiliations : Department of Electronic and Electrical Engineering, University College London; Department of Materials, Imperial College London
Resume : Resistive switches offer the prospect of improved performance, efficiency and scalability over current data storage methods. Many device architectures have been proposed, reliant upon a wide variety of materials whose conductance switches in a non-volatile manner with the application of an applied field. Silicon-based switching materials are of particular interest in these devices as they offer the added potential for integration into existing CMOS infrastructures. It is of great importance that the underlying physics of switching is well-understood, such that device optimisation and integration into commercial hardware may be realised. Our device layers are sputter-deposited to create a 37nm thick, non-stoichiometric, granular, silicon-rich layer of silica sandwiched between conductive electrodes. We report on the material changes leading to reversible resistive switching in silicon suboxide using secondary ion mass spectroscopy (SIMS), x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and conductive atomic force microscopy (cAFM). Analysis with a range of techniques serves to highlight the broad dynamics of device behaviour, and supports the model of an ionic and defect-dependent switching mechanism which relies upon the presence of nanoscale grain boundaries within the silica switching layer.
Authors : M.P.F. Graça a, B.M.G. Melo a, P.R. Prezas a, S.A. Salehizadeh a, F.N.A. Freire b, M.A. Valente a, L. Bih c
Affiliations : a Physics Department (I3N), Aveiro University, Campus Universitario de Santiago, Aveiro, Portugal; b Mechanics Engineering Department, Ceara Federal University, Fortaleza, Brazil; c Equipe Sciences de Mat?riaux, FST-Errachidia, Maroc;
Resume : Recently, new compositions of phosphate glasses with high chemical and thermal stability have been achieved, making them good candidates for several applications such as fast ionic conductors, semiconductors, photonic materials, hermetic seals, rare-earth ion host solid lasers and biomedical materials. Phosphate glasses doped with niobium might also have interesting applications including waste form for radioactive waste immobilization, rare-earth ion host for laser glasses, glass fibers and optical lenses, hermetic sealing, electrodes and agricultural applications. Additionally, it is known that materials like lithium niobate (LiNbO3), sodium niobate (NaNbO3) and potassium niobate (KNbO3), are important materials due to their excellent ferroelectric, pyroelectric, piezoelectric and photorefractive properties. In this work, functional phosphate glasses of the system 30PO_(5/2)-25NbO_(5/2)-10WO_3-25A_2 O-10B_2 O_3 where A=Li, Na and K were prepared by melt-quenching. The as-prepared glasses were heat-treated in air at temperatures up to 1000 ?C for 4 hours, which lead to the formation of glass-ceramics. dc (σ_dc), ac (σ_ac) conductivity and dielectric spectroscopy measurements were performed in function of the temperature (100-400 K) and related with their microstructure.
Authors : A. Stronski, O. Paiuk, Iu. Nasieka, V.Strelchuk, A.Gudymenko, I.Lischynskyi, A.Gubanova,
Affiliations : V. Lashkaryov Institute of Semiconductor Physics NAS of Ukraine, 42 Nauki ave., 03028 Kyiv, Ukraine; Precarpathian National University, Ivano-Frankivsk, Ukraine;Kamenets-Podolsky State University, Kamenets-Podolsky, Ukraine
Resume : In present work the results on influence of doping by transitional and rare earth elements on thermal, optical, luminescent, structural and magnetic properties of chalcogenide glasses are presented. Chalcogenide glasses (CG) doped with transitional and rare earth elements were synthesized by common melt-quenching technique. Thermal properties were studied using DSC technique. Structural studies were performed using Raman, IR spectroscopy and XRD. In Raman spectra main observed effect under introduction of dopants was change of relative concentration of main and non-stoichiometric structural units characteristic for CG. Luminescence of CG doped by Cr was studied in 800-1600nm region. Luminescence intensity increased with Cr concentration, thus showing on increased level of defects with the Cr introduction. CG modified by Yb have two bands of luminescence in near IR region which are characteristic for Yb3+ ion (λex = 980nm, room temperature). Influence of transition metals dopants on optical properties of CG was studied in mid-IR region. Observed changes are caused by interaction of the introduced dopants with non-stoichiometric structural elements present in glass and inherent impurities of host glass such as hydrogen and oxygen. Pure CG are diamagnetics. Transitional and rare earth impurities changes the magnetic properties of investigated CG. M(T) dependences were observed which are characteristic for paramagnetics and ferromagnetics in the paramagnetic temperature range.
Authors : J. Suresh Kumar, K. Pavani, S. A. Salehizadeh, M.P.F. Graça, M.J. Soares
Affiliations : Department of Physics & I3N, University of Aveiro, Aveiro 3810-193, Portugal
Resume : This paper reports on the preparation, optical absorption, NIR fluorescence and visible upconversion studies of neodymium doped bismuth barium tellurite glasses prepared by melt-quench method. The phonon energy of the glass was estimated by Raman spectrum. Radiative parameters of various transitions/levels were calculated by applying JuddOfelt (JO) theory. The concentration dependence of NIR emission and visible upconversion intensities from the 4F3/2 and 2D3/2 levels has been discussed. Decrease of experimental lifetime of 4F3/2 and 2D3/2 levels with concentration have also been discussed by recording decay curves of the NIR emission and upconversion spectra.
Authors : J. Suresh Kumar1, K. Pavani1, S. A. Salehizadeh1, M.P.F. Graça1, M.J. Soares1, P. Bragiel2, M. Piasecki2
Affiliations : 1Department of Physics & I3N, University of Aveiro, Aveiro-3810-193, Portugal; 2Institute of Physics , J.Długosz University, Al. Armii Krajowej 13/15,42-200 Częstochowa, Poland
Resume : Borosilicate glass with molar compositions, [(1−x)(60SiO220B2O320K2CO3 +x BaTiO3] with x = 0, 1, 2, 4, 6, 8, 10 (in mol%) were prepared. The amorphous nature and glassy characteristics of the samples were established via X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC) respectively. The nanocrystalline of BaTiO3 embedded in the network glass matrix at x = 10 mol% were established by DSC which is conﬁrmed by infrared spectroscopy study. Properties such as density, molar volume, dielectric constant, dielectric loss and ac conductivity, as a function of frequency (100 Hz1 MHz) and temperature (100600 K), have been investigated. The trends of these properties are attributed to changes in the glass network structure and presence of nanocrystallites of BaTiO3. The sample at x = 10 mol% exhibited dielectric anomaly and the CurieWeiss law was found to be valid at a temperature above the transition temperature (Tc).
Authors : Tahereh Naderishahab, Aliakbar Ahangary, Hamid. R. Khalesifard
Affiliations : Institute for Advanced Studies in Basic Sciences(IASBS), Zanjan, Iran
Resume : In this study, the ion exchange between Cu2+ and ion(s) in BK7 glasses were investigated. A mixture of cupric sulfate pentahydrate : Sodium sulfate (CuSO4.5H2O : Na2SO4) in a proportion of 68:32 Wt. % was molten in alumina crucibles at 600-690oC and, 2 mm thick BK7 glass slides were immersed in the molten mixture. The BK7 glass slides were retained in the molten mixture for time durations of 1, 2, 5, 10, 20, 60, 120, 180, 240, and 300 minutes respectively. After the ion-exchange process, an absorption band (centered around 290 nm) has been appeared over the optical absorption spectra of the samples. The changes of the optical absorption spectra of the ion exchanged samples have been monitored based on changes in the temperature and duration of the ion exchange. The results showed that by increasing the temperature, absorption peak of the ion exchanged samples were shifted toward longer wave lengths and the height of the absorption peak also increased. The evaluation of optical spectra of the ion exchange samples showed that, when the duration of ion-exchange is less than 180 min, the absorption peak of the samples at 290 nm shifted toward the longer wave lengths and the height of the absorption peak increased as well. In contrast, when the ion-exchange took longer than 180 min a blue shift was occurred and height of the absorption peak was decreased. Also interaction of an intense Ar+ laser beam (wavelength: 514 nm, power density: 0.26 MW/cm2) and one group of the ion-exchanged glasses (ion-exchange temperature and duration: 670oC and 180 min respectively) has been investigated. The duration of the interaction has been chosen as 1, 5, 10, 30, 60, 300 and 600. Interaction with the laser beam altered the optical absorption spectra of the samples and an absorption band around 327 nm has been appeared over the samples. By increasing the interaction duration from 1s to 60s the absorption peak over the mentioned band has been increased in height and got red shifted but for the interaction times larger than 60s the absorption band gradually has been vanished in a way that for the interaction time of 300s the peak and the absorption band, almost were disappeared and again appeared for the interaction time of 600s.
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Authors : Dominik Dorosz(1), Marcin Kochanowicz(1), Jacek Zmojda(1), Piotr Miluski(1), Jan Dorosz(1), Anna Lukowiak(2), Maurizio Ferrari(3)
Affiliations : (1) Bialystok University of Technology, Wiejska Street 45, 15-351 Bialystok, Poland (2) Institute of Low Temperature and Structure Research, PAS, 2 Okólna St., 50-422 Wroclaw, Poland (3) IFN - CNR CSMFO Lab., Via alla Cascata 56/C Povo, 38123 Trento, Italy
Resume : Development of new optoelectronic devices based on optical fibres is possible thanks to constant searching for advanced materials adapted to specific applications of optical fibre structures and also due to the development of technological processes used for their production or further processing. Special constructions of active optical fibres allow to optimise their parameters with regard to application of these fibres used in optoelectronic systems as lasers, amplifiers or sensors. Simultaneously, developing of glasses co-doped with RE ions leads to the constructions of new photonic devices required in integrated optics and sensor applications. The presentation will be dealt with optical and thermal properties of RE co-doped fluorophosphate glasses with the attention to their application in optical fibres. Presented glass system co-doped with Nd3+/Yb3+ as a result of excitation at the wavelength of 808 nm characterized strong and wide ( = 100 nm) emission in the 1m region corresponding to the superposition of optical transitions 4F3/2 → 4I11/2 (Nd3+) and 2F5/2 → 2F7/2 (Yb3+). The optimization of Nd3+ → Yb3+ resonant energy transfer in glass was possible because of a small difference in energy (~ 1190 cm-1) between the laser levels of neodymium and ytterbium. Described in the paper good thermal and luminescent properties of glass enable to manufacture optical fibers with amplified spontaneous emission (ASE) at 1.1 μm. Acknowledgments The research activity was performed in the Bialystok University of Technology project S/WE/4/2013 and the CNR-PAS joint project Nanostructured systems in opal configuration for the development of photonic devices (2014-2016). The COST Action MP1401 Advanced fibre laser and coherent source as tools for society, manufacturing and life science is also acknowledged.
Authors : Brigitte Boulard1, Simone Normani2, Anna Łukowiak3, Iustyna Vasilchenko2,4, Andrea Chiappini2, Alessandro Chiasera2, Claire Arfuso Duverger1, Stefano Pelli5,6, Inas K. Battisha7, Francesco Prudenzano8, Giancarlo C. Righini5,6, Marian Marciniak9, and Maurizio Ferrari2
Affiliations : 1Institut des Molécules et Matériaux du Mans, UMR 6283, Equipe Fluorures, Université du Maine, Av. Olivier Messiaen, 72085 Le Mans cedex 09, France. 2CNR-IFN, CSMFO Lab., Via alla Cascata 56/c, Povo, 38123 Trento, Italy. 3Institute of Low Temperature and Structure Research, PAS, ul. Okolna 2, 50-950 Wroclaw, Poland. 4Dipartimento di Fisica, Università di Trento, via Sommarive 14, Povo, 38123 Trento, Italy 5MDF Lab., IFAC - CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy. 6Centro di Studi e Ricerche Enrico Fermi, Piazza del Viminale 2, 00184 Roma, Italy. 7National Research Center, 12622 Dokki, Giza, Egypt. 8 Politecnico di Bari, DEI, Via E. Orabona 4, Bari, 70125, Italy. 9National Institute of Telecommunications, 1 Szachowa Street, 04 894 Warsaw, Poland
Resume : Glass-ceramics are nanocomposite materials which offer specific characteristics of capital importance in photonics. This kind of two-phase materials is constituted by nanocrystals embedded in a glass matrix and the respective composition and volume fractions of crystalline and amorphous phase determine the properties of the glass-ceramic. Among these properties transparency is crucial, in particular when confined structures, such as dielectric optical waveguides, are considered, and several works have been devoted to this topic. Another important point is the role of the nanocrystals when activated by luminescent species, as rare earth ions, and their effect on the spectroscopic properties of the glass-ceramic. The presence of the crystalline environment around the rare earth ion allows high absorption and emission cross sections, reduction of the non-radiative relaxation thanks to the lower phonon cut-off energy, and tailoring of the ion-ion interaction by the control of the rare earth ion partition. Fabrication, assessment and application of glass-ceramic photonic systems, especially waveguides, deserve an appropriate discussion which is the aim of this communication, focused on luminescent glass-ceramics. A brief historical review, consolidated results and recent advances in this important scientific and technological area will be presented, and some perspectives will be outlined. Acknowledgements This research was performed in the framework of the MAE Significant Bilate
Authors : Francesco Scotognella1,2,*, Alessandro Chiasera3, Luigino Criante2, Stefano Varas3, Stefano Pelli4,5, Anna Łukowiak6, Giancarlo C. Righini4,5, Roberta Ramponi1, Maurizio Ferrari3,6
Affiliations : 1 Politecnico di Milano, Dipartimento di Fisica and Istituto di Fotonica e Nanotecnologie CNR, Piazza Leonardo da Vinci 32, 20133 Milano 2 CNR-IFN CSMFO Lab, Via alla Cascata 56/C, Povo, 38123 Trento, Italy 3 Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, Via Giovanni Pascoli, 70/3, 20133, Milan, Italy 4 IFAC - CNR, MiPLab, via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy. 5 Museo Storico della Fisica e Centro di Studi e Ricerche Enrico Fermi, P. Viminale 1, 00184 Rome, Italy. 6 Institute of Low Temperature and Structure Research, PAS, ul. Okolna 2, 50-422 Wroclaw, Poland.
Resume : The investigation of the differences between ordered and disordered materials (in the hundreds of nanometer lengthscale) is a crucial topic for a better understanding of light transport in photonic media. In this work, we study the light transmission properties of disordered one dimensional photonic structures in which disorder is introduced by a random variation of layer thickness. The structures have been fabricated by rf-sputtering technique. The transmission spectrum of the disordered structure has been carefully simulated by taking into account the refractive index dispersion of silicon dioxide and titanium dioxide, resulting in a very good agreement between the experimental data and the simulations. We found that the transmission of the photonic structure in the range 300 1200 nm is lower with respect the corresponding periodic photonic crystal. This study envisages the use of disordered one dimensional photonic structures for the modelization and realization of broad band filters. Acknowledgments The research activity was performed in the framework of CNR-PAS joint project Nanostructured systems in opal configuration for the development of photonic devices (2014-2016) and Progetto Premiale Strutture risonanti per la rivelazione di biomarkers precursori della sepsi. The COST Action MP1401 Advanced fibre laser and coherent source as tools for society, manufacturing and life science is also acknowledged.
Authors : Adriana Scarangella (1,2), Maria Miritello (2), Giorgia Franzò (2), Alessia Irrera (3), Cristiano DAndrea (2), Francesco Priolo (1,2).
Affiliations : (1) MATIS-IMM CNR, Via S. Sofia 64, 95123 Catania, Italy; (2) Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy; (3) IPCF-CNR, Viale Ferdinando Stagno d'Alcontres 37, 98158 Messina, Italy.
Resume : In the last decades erbium-containing materials have been widely used as active media in large-scale communication systems, due to the fact that Er emission at 1.54 micron corresponds to a minimum of loss in silica optical fibers. However, the low Er content that can be insert without precipitation in optically inactive Er-clusters and the low Er excitation cross section are limiting factors for its optical efficiency. A possible approach to overcome the solubility limit is the development of yttrium-erbium based compounds in which Er concentration can be modulated, by replacing Y in substitutional positions. In this way up to 10E22 Er/cm3 can be introduced in Y-Er oxides and silicates. To further enhance Er excitation cross section, we propose the insertion of bismuth in Er-Y oxide thin film deposited by magnetron co-sputtering. The Bi influence on structural and optical properties of the compound will be widely discussed. In particular Bi will be demonstrated to act as an efficient sensitizer for Er, when Bi3+ oxidation state is favored, by determining an increase of more than three order of magnitude of Er effective excitation cross section. Moreover, we will evaluate the effects of Ag and Au nanoparticles with different sizes and shapes for tuning their plasmon resonance in the energy range of Bi and Er levels, in order to induce plasmon-photon coupling. The results suggest Bi-doped Y-Er compounds as novel and efficient emitter at 1.54 micron for photonic applications.
Authors : Jean-Emmanuel Broquin, Elise Ghibaudo, Lionel Bastard and Davide Bucci
Affiliations : Institut de Microélectronique Electromagnétisme et Photonique Minatec - Grenoble INP 3 Parvis Louis Neel CS 50257 F - 38016 Grenoble Cedex 1 FRANCE
Resume : In 1969, when Miller proposed to mimic the new born integrated circuit and create integrated optical devices, he already identified « doped » glass substrates as potential candidates for this new type of circuitry. After years of research and development on both material science, guided wave theory and microtechnology, the many devices that have been realized and, for some of them, commercialized proved Millers vision was right. In this article, we will review the field of glass integrated optic, from the very first results of the late 1970s to the most recent developments concerning biochips, optofluidic devices in harsh environment, integrated lasers and amplifiers as well as 3D integration. Finally, we will identify and put emphasis on some of the many challenges that need to be addressed in the future, trying to propose some potential solutions.
Authors : S. A. Salehizadeh; M. P. F. Graça; M. A. Valente
Affiliations : I3N - Department of Physics, University of Aveiro, Campus Santiago, 3810-193 Aveiro, Portugal; I3N - Department of Physics, University of Aveiro, Campus Santiago, 3810-193 Aveiro, Portugal; I3N - Department of Physics, University of Aveiro, Campus Santiago, 3810-193 Aveiro, Portugal
Resume : The complex impedance data of 50TeO2-(50-x)V2O5-xK2O with 0 x 15 (in mol%) mixed conductor glasses, prepared using melt quenching method, have been analyzed due to their potentiality in electrochemical technology as a promising solid electrolyte. The dielectric data was measured in the temperature range between 200 K and 370 K and frequency range between 100 Hz and 1 MHz. No dielectric relaxation was observed in al samples using the permittivity formalism. However, using the impedance formalism a dielectric relaxation phenomenon was observed in all samples. These spectra were fitted using an equivalent electric circuit, constituted by a parallel/series combination of resistor and constant phase (CPE) elements. This analysis revealed the presence of two dielectric relaxations, one at very low frequencies (< 100 Hz) and a second at frequencies above 1 kHz. The obtained values of the equivalent circuit elements were found to be both composition and temperature-dependent showing both ionic and polaronic conductions and polarization dynamic process. Using the dielectric modulus formalism clarify that the observed relaxation process is thermally activated with a non-Debye behavior. The relaxation behavior is related with the amount of K+ ions in each sample.
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Authors : M. Fasoli1, M. C. Cantone2, N. Chiodini1, C. De Mattia2, E. Mones3, I. Veronese2, A. Vedda1
Affiliations : 1Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, Via Cozzi 55, 20125 Milano, Italy 2Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy 3Medical Physics Department, Azienda Ospedaliera Maggiore della Carità, Corso Mazzini 18, 28100 Novara, Italy
Resume : An optical fibre based dosimeter consists of a small scintillator coupled to a passive fibre of suitable length for remote signal transport to an optical detector. Such configuration has several advantages in radiation dosimetry. Indeed, the small volume of the sensor makes the radiation field perturbation negligible, leading to high spatial resolution and point dose evaluations. These systems may enable a real-time measurement of the dose, providing a direct feedback to the medical physician during a radiation therapy treatment as well as dosimetric information during diagnostic irradiations. In this work the recent progresses in the development of rare-earth doped silica fibers are shown. In particular, the main purpose was the production of scintillating fibers with an emission spectrum which can be easily distinguished from that of spurious luminescent signals originated in the fiber material as a consequence of the exposition to ionizing radiations (e.g. Cherenkov light and intrinsic fluorescence). Therefore, rare earth dopants like Eu and Yb were considered for the scintillating fiber development, and the results were compared to those obtained on previously investigated Ce-doped fibers. A study of the luminescent and dosimetric properties of these new systems was carried out by using X and gamma rays of different energies. Furthermore, a detailed investigation of the mechanisms responsible for possible sensitivity changes upon accumulated dose was performed.
Authors : A. Stronski1, E. Achimova2, D. Grynko1
Affiliations : 1 V. Lashkaryov Institute of Semiconductor Physics NAS of Ukraine, Kyiv, Ukraine; 2 Institute of Applied Physics AS of Moldova
Resume : The purpose of this presentation is to analyse ways for design and synthesis new nanocomposite materials based on chalcogenide glass semiconductor (ChGS). Additive component may be organic dye, chalcogene, transitional or rare-earth metals. Thermal evaporation of ChGS and additive component was carried out in vacuum using two evaporators, with their power carefully regulated. Molecular beams of two components were measured separately by quartz microbalance. Hardware-software system was used to correct evaporators power in real time, allowing to hold molecular ratio of the composite during film growth. The spatial arrangement of the two evaporators and substrates in a vacuum chamber provided simultaneous production of a set of samples with composite ratio that varied over a wide range. Such technique allows change properties of obtained media predictably changing their physical and chemical properties. Structural studies were carried with the use of Raman and IR spectroscopy and X-ray diffraction, films morphology with the use of AFM microscopy. Enclosure of organic dye and other dopants in the chalcogenide glass matrix can generate new energy states in the forbidden gap, significantly change their optical, luminescent, magnetic, thermal and non-linear optical properties. Possible mechanism of the observed direct relief formation can be molar volume change of composite nanomultilayer system under the action of light. These media can be used for the fabrication of different optical elements including direct one-step relief formation with the use of amorphous chalcogenide multilayers and in other applications. The research was supported by the project FP7 SECURER21
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