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Physicist, graduated with “laurea” in the University of Florence, Italy, in 1967, he worked for more than 40 years at the National Research Council of Italy (CNR), where he got the position of research director at the Nello Carrara Institute of Applied Physics (IFAC). He was director of CNR National Group of Quantum Electronics & Plasma Physics (1983-1996) and director of CNR Dept. of Materials and Devices (2006-2009). Retired from CNR at the end of 2010, he was director of Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi (Enrico Fermi Centre), in Rome, Italy (2012-2016). He now holds a position of Associate Scientist at IFAC CNR. He has tutored more than 20 MSc and PhD students in Italy and has been member of several PhD juries in Europe. Co-founder and then President of the Italian Society of Optics and Photonics (SIOF) -- Vice-President of IUPAP (International Union of Pure and Applied Physics) -- Vice-President of ICO (International Commission for Optics) -- Secretary of EOS (European Optical Society) -- member of the Board of Directors of SPIE -- President of the Italian Committee for Promotion of Optical Sciences and Technologies (FOTONICA.IT). Currently (August 2020) he is chair of Technical Committee TC-20 (Photonic Glasses and optical fibers) of the International Commission on Glass, and honorary chair of the International Workshop "Photoluminescence in Rare Earths". Author of more than 500 papers; editor or co-editor of 4 books
Ion exchange in glass has a long history as a simple and effective technology to produce gradient-index structures and has been largely exploited in industry and in research laboratories. In particular, ion-exchanged waveguide technology has served as an excellent platform for theoretical and experimental studies on integrated optical circuits, with successful applications in optical communications, optical processing and optical sensing. It should not be forgotten that the ion-exchange process can be exploited in crystalline materials, too, and several crucial devices, such as optical modulators and frequency doublers, have been fabricated by ion exchange in lithium niobate. Here, however, we are concerned only with glass material, and a brief review is presented of the main aspects of optical waveguides and passive and active integrated optical elements, as directional couplers, waveguide gratings, integrated optical amplifiers and lasers, all fabricated by ion exchange in glass. Then, some promising research activities on ion-exchanged glass integrated photonic devices, and in particular quantum devices (quantum circuits), are analyzed. An emerging type of passive and/or reconfigurable devices for quantum cryptography or even for specific quantum processing tasks are presently gaining an increasing interest in integrated photonics; accordingly, we propose their implementation by using ion-exchanged glass waveguides, also foreseeing their integration with ion-exchanged glass lasers.
Giancarlo Righini; Jesús Liñares. Active and Quantum Integrated Photonic Elements by Ion Exchange in Glass. Applied Sciences 2021, 11, 5222 .
AMA StyleGiancarlo Righini, Jesús Liñares. Active and Quantum Integrated Photonic Elements by Ion Exchange in Glass. Applied Sciences. 2021; 11 (11):5222.
Chicago/Turabian StyleGiancarlo Righini; Jesús Liñares. 2021. "Active and Quantum Integrated Photonic Elements by Ion Exchange in Glass." Applied Sciences 11, no. 11: 5222.
Glasses, in their different forms and compositions, have special properties that are not found in other materials. The combination of transparency and hardness at room temperature, combined with a suitable mechanical strength and excellent chemical durability, makes this material indispensable for many applications in different technological fields (as, for instance, the optical fibres which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors). For its part, ion-exchange from molten salts is a well-established, low-cost technology capable of modifying the chemical-physical properties of glass. The synergy between ion-exchange and glass has always been a happy marriage, from its ancient historical background for the realisation of wonderful artefacts, to the discovery of novel and fascinating solutions for modern technology (e.g., integrated optics). Getting inspiration from some hot topics related to the application context of this technique, the goal of this critical review is to show how ion-exchange in glass, far from being an obsolete process, can still have an important impact in everyday life, both at a merely commercial level as well as at that of frontier research.
Simone Berneschi; Giancarlo Righini; Stefano Pelli. Towards a Glass New World: The Role of Ion-Exchange in Modern Technology. Applied Sciences 2021, 11, 4610 .
AMA StyleSimone Berneschi, Giancarlo Righini, Stefano Pelli. Towards a Glass New World: The Role of Ion-Exchange in Modern Technology. Applied Sciences. 2021; 11 (10):4610.
Chicago/Turabian StyleSimone Berneschi; Giancarlo Righini; Stefano Pelli. 2021. "Towards a Glass New World: The Role of Ion-Exchange in Modern Technology." Applied Sciences 11, no. 10: 4610.
The development of the information technology and, very recently, of new application scenarios like Internet of Things (IoT) and Industry 4.0 has pushed the research towards new technological platforms. In this frame, the spatial freedom permitted by flexible short-range connections and flexible devices has become as important as “classical” parameters such as low weight, low power consumption, and electromagnetic immunity. Accordingly, first the flexible electronics and later the flexible photonics have produced innovative components and devices. The present paper aims at presenting a brief overview of this broad area, underlining the achievements and the remaining challenges in the different routes to the manufacturing of flexible photonic devices. Material platforms remain at the core of such developments, and it is interesting to note that glassy materials still constitute a fundamental piece in the present and future scenario.
Giancarlo C. Righini; Justyna Krzak; Anna Lukowiak; Guglielmo Macrelli; Stefano Varas; Maurizio Ferrari. From flexible electronics to flexible photonics: A brief overview. Optical Materials 2021, 115, 111011 .
AMA StyleGiancarlo C. Righini, Justyna Krzak, Anna Lukowiak, Guglielmo Macrelli, Stefano Varas, Maurizio Ferrari. From flexible electronics to flexible photonics: A brief overview. Optical Materials. 2021; 115 ():111011.
Chicago/Turabian StyleGiancarlo C. Righini; Justyna Krzak; Anna Lukowiak; Guglielmo Macrelli; Stefano Varas; Maurizio Ferrari. 2021. "From flexible electronics to flexible photonics: A brief overview." Optical Materials 115, no. : 111011.
Optical fibre micro/nano tips (OFTs), defined here as tapered fibres with a waist diameter ranging from a few microns to tens of nanometres and different tip angles (i.e., from tens of degrees to fractions of degrees), represent extremely versatile tools that have attracted growing interest during these last decades in many areas of photonics. The field of applications can range from physical and chemical/biochemical sensing—also at the intracellular levels—to the development of near-field probes for microscope imaging (i.e., scanning near-field optical microscopy (SNOM)) and optical interrogation systems, up to optical devices for trapping and manipulating microparticles (i.e., optical tweezers). All these applications rely on the ability to fabricate OFTs, tailoring some of their features according to the requirements determined by the specific application. In this review, starting from a short overview of the main fabrication methods used for the realisation of these optical micro/nano structures, the focus will be concentrated on some of their intriguing applications such as the development of label-based chemical/biochemical sensors and the implementation of SNOM probes for interrogating optical devices, including whispering gallery mode microcavities.
Simone Berneschi; Andrea Barucci; Francesco Baldini; Franco Cosi; Franco Quercioli; Stefano Pelli; Giancarlo Righini; Bruno Tiribilli; Sara Tombelli; Cosimo Trono; Ambra Giannetti. Optical Fibre Micro/Nano Tips as Fluorescence-Based Sensors and Interrogation Probes. Optics 2020, 1, 213 -242.
AMA StyleSimone Berneschi, Andrea Barucci, Francesco Baldini, Franco Cosi, Franco Quercioli, Stefano Pelli, Giancarlo Righini, Bruno Tiribilli, Sara Tombelli, Cosimo Trono, Ambra Giannetti. Optical Fibre Micro/Nano Tips as Fluorescence-Based Sensors and Interrogation Probes. Optics. 2020; 1 (2):213-242.
Chicago/Turabian StyleSimone Berneschi; Andrea Barucci; Francesco Baldini; Franco Cosi; Franco Quercioli; Stefano Pelli; Giancarlo Righini; Bruno Tiribilli; Sara Tombelli; Cosimo Trono; Ambra Giannetti. 2020. "Optical Fibre Micro/Nano Tips as Fluorescence-Based Sensors and Interrogation Probes." Optics 1, no. 2: 213-242.
There is some incertitude on the creation of the term “photonics” and some ambiguity about its frontiers (and differences with respect to optoelectronics and electro-optics)
Luigi Sirleto; Giancarlo C. Righini. Editorial for the Special Issue on Nonlinear Photonics Devices. Micromachines 2020, 11, 760 .
AMA StyleLuigi Sirleto, Giancarlo C. Righini. Editorial for the Special Issue on Nonlinear Photonics Devices. Micromachines. 2020; 11 (8):760.
Chicago/Turabian StyleLuigi Sirleto; Giancarlo C. Righini. 2020. "Editorial for the Special Issue on Nonlinear Photonics Devices." Micromachines 11, no. 8: 760.
The optical photoluminescent (PL) emission of Yb3+ ions in the near infrared (NIR) spectral region at about 950–1100 nm has many potential applications, from photovoltaics to lasers and visual devices. However, due to their simple energy-level structure, Yb3+ ions cannot directly absorb UV or visible light, putting serious limits on their use as light emitters. In this paper we describe a broadband and efficient strategy for sensitizing Yb3+ ions by Ag codoping, resulting in a strong 980 nm PL emission under UV and violet-blue light excitation. Yb-doped silica–zirconia–soda glass–ceramic films were synthesized by sol-gel and dip-coating, followed by annealing at 1000 °C. Ag was then introduced by ion-exchange in a molten salt bath for 1 h at 350 °C. Different post-exchange annealing temperatures for 1 h in air at 380 °C and 430 °C were compared to investigate the possibility of migration/aggregation of the metal ions. Studies of composition showed about 1–2 wt% Ag in the exchanged samples, not modified by annealing. Structural analysis reported the stabilization of cubic zirconia by Yb-doping. Optical measurements showed that, in particular for the highest annealing temperature of 430 °C, the potential improvement of the material’s quality, which would increase the PL emission, is less relevant than Ag-aggregation, which decreases the sensitizers number, resulting in a net reduction of the PL intensity. However, all the Ag-exchanged samples showed a broadband Yb3+ sensitization by energy transfer from Ag aggregates, clearly attested by a broad photoluminescence excitation spectra after Ag-exchange, paving the way for applications in various fields, such as solar cells and NIR-emitting devices.
Francesco Enrichi; Elti Cattaruzza; Tiziano Finotto; Pietro Riello; Giancarlo C. Righini; Enrico Trave; Alberto Vomiero. Ag-Sensitized NIR-Emitting Yb3+-Doped Glass-Ceramics. Applied Sciences 2020, 10, 2184 .
AMA StyleFrancesco Enrichi, Elti Cattaruzza, Tiziano Finotto, Pietro Riello, Giancarlo C. Righini, Enrico Trave, Alberto Vomiero. Ag-Sensitized NIR-Emitting Yb3+-Doped Glass-Ceramics. Applied Sciences. 2020; 10 (6):2184.
Chicago/Turabian StyleFrancesco Enrichi; Elti Cattaruzza; Tiziano Finotto; Pietro Riello; Giancarlo C. Righini; Enrico Trave; Alberto Vomiero. 2020. "Ag-Sensitized NIR-Emitting Yb3+-Doped Glass-Ceramics." Applied Sciences 10, no. 6: 2184.
Photonic crystals (PhC) are spatially ordered structures with lattice parameters comparable to the wavelength of propagating light. Their geometrical and refractive index features lead to an energy band structure for photons, which may allow or forbid the propagation of electromagnetic waves in a limited frequency range. These unique properties have attracted much attention for both theoretical and applied research. Devices such as high-reflection omnidirectional mirrors, low-loss waveguides, and high- and low-reflection coatings have been demonstrated, and several application areas have been explored, from optical communications and color displays to energy harvest and sensors. In this latter area, photonic crystal fibers (PCF) have proven to be very suitable for the development of highly performing sensors, but one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) PhCs have been successfully employed, too. The working principle of most PhC sensors is based on the fact that any physical phenomenon which affects the periodicity and the refractive index of the PhC structure induces changes in the intensity and spectral characteristics of the reflected, transmitted or diffracted light; thus, optical measurements allow one to sense, for instance, temperature, pressure, strain, chemical parameters, like pH and ionic strength, and the presence of chemical or biological elements. In the present article, after a brief general introduction, we present a review of the state of the art of PhC sensors, with particular reference to our own results in the field of mechanochromic sensors. We believe that PhC sensors based on changes of structural color and mechanochromic effect are able to provide a promising, technologically simple, low-cost platform for further developing devices and functionalities.
Andrea Chiappini; Lam Thi Ngoc Tran; Pablo Marco Trejo-García; Lidia Zur; Anna Lukowiak; Maurizio Ferrari; Giancarlo C. Righini. Photonic Crystal Stimuli-Responsive Chromatic Sensors: A Short Review. Micromachines 2020, 11, 290 .
AMA StyleAndrea Chiappini, Lam Thi Ngoc Tran, Pablo Marco Trejo-García, Lidia Zur, Anna Lukowiak, Maurizio Ferrari, Giancarlo C. Righini. Photonic Crystal Stimuli-Responsive Chromatic Sensors: A Short Review. Micromachines. 2020; 11 (3):290.
Chicago/Turabian StyleAndrea Chiappini; Lam Thi Ngoc Tran; Pablo Marco Trejo-García; Lidia Zur; Anna Lukowiak; Maurizio Ferrari; Giancarlo C. Righini. 2020. "Photonic Crystal Stimuli-Responsive Chromatic Sensors: A Short Review." Micromachines 11, no. 3: 290.
The ordered SiO2:Er3+ inverse opal films were fabricated by sol‐gel technique in combination with a self‐assembly method to examine their potential as a suitable platform to tailor the spontaneous emission lifetime of Er3+ ions and its concentration quenching. Good ordering on long range scale has been evidenced by means of Scanning Electron Microscopy, while reflectance measurements displayed a green bright color, as it results from optical Bragg diffraction from the (111) crystal planes. Moreover, it has been observed that the spontaneous decay rates (SDRs) of the inverse opals are suppressed, in contrast to the corresponding reference samples, due to the modulation of the effective refractive index (neff), in agreement with the virtual cavity model. At the same time, the reduced concentration quenching of Er3+ is attributed to the periodic empty cavity of the inverse opals. These results demonstrate that inverse opals can provide a tool for the enhancement of the NIR luminescence. This article is protected by copyright. All rights reserved.
Andrea Chiappini; Cristina Armellini; Nicola Bazzanella; Somayeh Nodehi; Anna Lukowiak; Silvia Maria Pietralunga; Valentina Piccolo; Daniele Zonta; Gualtiero Nunzi Conti; Giancarlo C. Righini; Maurizio Ferrari. Modification of the Near‐Infrared Spontaneous Emission in Er 3+ ‐Activated Inverse Silica Opals. physica status solidi (b) 2019, 257, 1 .
AMA StyleAndrea Chiappini, Cristina Armellini, Nicola Bazzanella, Somayeh Nodehi, Anna Lukowiak, Silvia Maria Pietralunga, Valentina Piccolo, Daniele Zonta, Gualtiero Nunzi Conti, Giancarlo C. Righini, Maurizio Ferrari. Modification of the Near‐Infrared Spontaneous Emission in Er 3+ ‐Activated Inverse Silica Opals. physica status solidi (b). 2019; 257 (8):1.
Chicago/Turabian StyleAndrea Chiappini; Cristina Armellini; Nicola Bazzanella; Somayeh Nodehi; Anna Lukowiak; Silvia Maria Pietralunga; Valentina Piccolo; Daniele Zonta; Gualtiero Nunzi Conti; Giancarlo C. Righini; Maurizio Ferrari. 2019. "Modification of the Near‐Infrared Spontaneous Emission in Er 3+ ‐Activated Inverse Silica Opals." physica status solidi (b) 257, no. 8: 1.
Glasses doped with rare earth elements possess unique photoluminescence properties. They find application in several devices, such as lasers, optical amplifiers, and sensors. More recently, rare-earth doped glass thin films have been the subject of investigation for the development of frequency-converting layers able to increase the efficiency of silicon solar cells. Another approach to the improvement of the performance of a solar cell is based on the capture of a larger flux of light by the detector, which can be obtained by surface texture, plasmonics, or waveguide structures. Here, the recent advances in this area will be briefly reviewed.
G.C. Righini; F. Enrichi; L. Zur; M. Ferrari. Rare-earth doped glasses and light managing in solar cells. Journal of Physics: Conference Series 2019, 1221, 012028 .
AMA StyleG.C. Righini, F. Enrichi, L. Zur, M. Ferrari. Rare-earth doped glasses and light managing in solar cells. Journal of Physics: Conference Series. 2019; 1221 (1):012028.
Chicago/Turabian StyleG.C. Righini; F. Enrichi; L. Zur; M. Ferrari. 2019. "Rare-earth doped glasses and light managing in solar cells." Journal of Physics: Conference Series 1221, no. 1: 012028.
Low threshold coherent emission at 1.5 µm is achieved using Er3+-doped dielectric 1D microcavities fabricated with a Radio Frequency-sputtering technique. The microcavities are composed of a half-wavelength Er3+-doped SiO2 active layer inserted between two Bragg reflectors consisting of ten, five, and seven pairs of SiO2/TiO2 layers, also doped with Er3+ ions. The morphology of the structure is inspected using scanning electron microscopy. Transmission measurements show the third and first order cavity resonance at 530 nm and 1.5 µm, respectively. The photoluminescence measurements are obtained using the optical excitation at the third order cavity resonance using a 514.5 nm Ar+ laser or Xe excitation lamp at 514.5 nm, with an excitation angle of 30°. The full width at half maximum of the emission peak at 1535 nm decreased with the pump power until the spectral resolution of the detection system was 2.7 nm. Moreover, the emission intensity presents a non-linear behavior with the pump power and a threshold at about 4 µW.
Cesare Meroni; Francesco Scotognella; Yann Boucher; Anna Lukowiak; Davor Ristic; Giorgio Speranza; Stefano Varas; Lidia Zur; Mile Ivanda; Stefano Taccheo; Roberta Ramponi; Giancarlo C. Righini; Maurizio Ferrari; Alessandro Chiasera. Low-Threshold Coherent Emission at 1.5 µm from Fully Er3+ Doped Monolithic 1D Dielectric Microcavity Fabricated Using Radio Frequency Sputtering. Ceramics 2019, 2, 74 -85.
AMA StyleCesare Meroni, Francesco Scotognella, Yann Boucher, Anna Lukowiak, Davor Ristic, Giorgio Speranza, Stefano Varas, Lidia Zur, Mile Ivanda, Stefano Taccheo, Roberta Ramponi, Giancarlo C. Righini, Maurizio Ferrari, Alessandro Chiasera. Low-Threshold Coherent Emission at 1.5 µm from Fully Er3+ Doped Monolithic 1D Dielectric Microcavity Fabricated Using Radio Frequency Sputtering. Ceramics. 2019; 2 (1):74-85.
Chicago/Turabian StyleCesare Meroni; Francesco Scotognella; Yann Boucher; Anna Lukowiak; Davor Ristic; Giorgio Speranza; Stefano Varas; Lidia Zur; Mile Ivanda; Stefano Taccheo; Roberta Ramponi; Giancarlo C. Righini; Maurizio Ferrari; Alessandro Chiasera. 2019. "Low-Threshold Coherent Emission at 1.5 µm from Fully Er3+ Doped Monolithic 1D Dielectric Microcavity Fabricated Using Radio Frequency Sputtering." Ceramics 2, no. 1: 74-85.
Note: In lieu of an abstract, this is an excerpt from the first page.Excerpt Glassy materials, i
Giancarlo C. Righini; Nicoletta Righini. Editorial for the Special Issue on Glassy Materials Based Microdevices. Micromachines 2019, 10, 39 .
AMA StyleGiancarlo C. Righini, Nicoletta Righini. Editorial for the Special Issue on Glassy Materials Based Microdevices. Micromachines. 2019; 10 (1):39.
Chicago/Turabian StyleGiancarlo C. Righini; Nicoletta Righini. 2019. "Editorial for the Special Issue on Glassy Materials Based Microdevices." Micromachines 10, no. 1: 39.
Solar cells are electrical devices that can directly convert sunlight into electricity. While solar cells are a mature technology, their efficiencies are still far below the theoretical limit. The major losses in a typical semiconductor solar cell are due to the thermalization of electrons in the UV and visible range of the solar spectrum, the inability of a solar cell to absorb photons with energies below the electronic band gap, and losses due to the recombination of electrons and holes, which mainly occur at the contacts. These prevent the realization of the theoretical efficiency limit of 85% for a generic photovoltaic device. A promising strategy to harness light with minimum thermal losses outside the typical frequency range of a single junction solar cell could be frequency conversion using rare earth ions, as suggested by Trupke. In this work, we discuss the modelling of generic frequency conversion processes in the context of solar cell device simulations, which can be used to supplement experimental studies. In the spirit of a proof-of-concept study, we limit the discussion to up-conversion and restrict ourselves to a simple rare earth model system, together with a basic diode model for a crystalline silicon solar cell. The results of this show that these simulations are very useful for the development of new types of highly efficient solar cells.
Alexander Quandt; Tahir Aslan; Itumeleng Mokgosi; Robert Warmbier; Maurizio Ferrari; Giancarlo Righini. About the Implementation of Frequency Conversion Processes in Solar Cell Device Simulations. Micromachines 2018, 9, 435 .
AMA StyleAlexander Quandt, Tahir Aslan, Itumeleng Mokgosi, Robert Warmbier, Maurizio Ferrari, Giancarlo Righini. About the Implementation of Frequency Conversion Processes in Solar Cell Device Simulations. Micromachines. 2018; 9 (9):435.
Chicago/Turabian StyleAlexander Quandt; Tahir Aslan; Itumeleng Mokgosi; Robert Warmbier; Maurizio Ferrari; Giancarlo Righini. 2018. "About the Implementation of Frequency Conversion Processes in Solar Cell Device Simulations." Micromachines 9, no. 9: 435.
The development of efficient luminescent systems, such as microcavities, solid-state lasers, integrated optical amplifiers, and optical sensors is the main topic in glass photonics. The building blocks of these systems are glass-ceramics activated by rare-earth ions because they exhibit specific morphologic, structural, and spectroscopic properties. Among various materials that could be used as nanocrystals to be imbedded in a silica matrix, tin dioxide presents some interesting peculiarities, e.g., the presence of tin dioxide nanocrystals allows an increase in both solubility and emission of rare-earth ions. Here, we focus our attention on Er3+—doped silica—tin dioxide photonic glass-ceramics fabricated by a sol-gel route. Although the SiO2-SnO2:Er3+ could be fabricated in different forms, such as thin films, monoliths, and planar waveguides, we herein limit ourselves to the monoliths. The effective role of tin dioxide as a luminescence sensitizer for Er3+ ions is confirmed by spectroscopic measurements and detailed fabrication protocols are discussed.
Lam Thi Ngoc Tran; Damiano Massella; Lidia Zur; Alessandro Chiasera; Stefano Varas; Cristina Armellini; Giancarlo C. Righini; Anna Lukowiak; Daniele Zonta; Maurizio Ferrari. SiO2-SnO2:Er3+ Glass-Ceramic Monoliths. Applied Sciences 2018, 8, 1335 .
AMA StyleLam Thi Ngoc Tran, Damiano Massella, Lidia Zur, Alessandro Chiasera, Stefano Varas, Cristina Armellini, Giancarlo C. Righini, Anna Lukowiak, Daniele Zonta, Maurizio Ferrari. SiO2-SnO2:Er3+ Glass-Ceramic Monoliths. Applied Sciences. 2018; 8 (8):1335.
Chicago/Turabian StyleLam Thi Ngoc Tran; Damiano Massella; Lidia Zur; Alessandro Chiasera; Stefano Varas; Cristina Armellini; Giancarlo C. Righini; Anna Lukowiak; Daniele Zonta; Maurizio Ferrari. 2018. "SiO2-SnO2:Er3+ Glass-Ceramic Monoliths." Applied Sciences 8, no. 8: 1335.
Rare earth doped materials play a very important role in the development of many photonic devices, such as optical amplifiers and lasers, frequency converters, solar concentrators, up to quantum information storage devices. Among the rare earth ions, ytterbium is certainly one of the most frequently investigated and employed. The absorption and emission properties of Yb3+ ions are related to transitions between the two energy levels 2F7/2 (ground state) and 2F5/2 (excited state), involving photon energies around 1.26 eV (980 nm). Therefore, Yb3+ cannot directly absorb UV or visible light, and it is often used in combination with other rare earth ions like Pr3+, Tm3+, and Tb3+, which act as energy transfer centres. Nevertheless, even in those co-doped materials, the absorption bandwidth can be limited, and the cross section is small. In this paper, we report a broadband and efficient energy transfer process between Ag dimers/multimers and Yb3+ ions, which results in a strong PL emission around 980 nm under UV light excitation. Silica-zirconia (70% SiO2-30% ZrO2) glass-ceramic films doped by 4 mol.% Yb3+ ions and an additional 5 mol.% of Na2O were prepared by sol-gel synthesis followed by a thermal annealing at 1000 °C. Ag introduction was then obtained by ion-exchange in a molten salt bath and the samples were subsequently annealed in air at 430 °C to induce the migration and aggregation of the metal. The structural, compositional, and optical properties were investigated, providing evidence for efficient broadband sensitization of the rare earth ions by energy transfer from Ag dimers/multimers, which could have important applications in different fields, such as PV solar cells and light-emitting near-infrared (NIR) devices.
Francesco Enrichi; Elti Cattaruzza; Maurizio Ferrari; Francesco Gonella; Riccardo Ottini; Pietro Riello; Giancarlo C. Righini; Trave Enrico; Alberto Vomiero; Lidia Zur. Ag-Sensitized Yb3+ Emission in Glass-Ceramics. Micromachines 2018, 9, 380 .
AMA StyleFrancesco Enrichi, Elti Cattaruzza, Maurizio Ferrari, Francesco Gonella, Riccardo Ottini, Pietro Riello, Giancarlo C. Righini, Trave Enrico, Alberto Vomiero, Lidia Zur. Ag-Sensitized Yb3+ Emission in Glass-Ceramics. Micromachines. 2018; 9 (8):380.
Chicago/Turabian StyleFrancesco Enrichi; Elti Cattaruzza; Maurizio Ferrari; Francesco Gonella; Riccardo Ottini; Pietro Riello; Giancarlo C. Righini; Trave Enrico; Alberto Vomiero; Lidia Zur. 2018. "Ag-Sensitized Yb3+ Emission in Glass-Ceramics." Micromachines 9, no. 8: 380.
Microspheres made of glass, polymer, or crystal material have been largely used in many application areas, extending from paints to lubricants, to cosmetics, biomedicine, optics and photonics, just to mention a few. Here the focus is on the applications of glassy microspheres in the field of energy, namely covering issues related to their use in solar cells, in hydrogen storage, in nuclear fusion, but also as high-temperature insulators or proppants for shale oil and gas recovery. An overview is provided of the fabrication techniques of bulk and hollow microspheres, as well as of the excellent results made possible by the peculiar properties of microspheres. Considerations about their commercial relevance are also added.
Giancarlo C. Righini. Glassy Microspheres for Energy Applications. Micromachines 2018, 9, 379 .
AMA StyleGiancarlo C. Righini. Glassy Microspheres for Energy Applications. Micromachines. 2018; 9 (8):379.
Chicago/Turabian StyleGiancarlo C. Righini. 2018. "Glassy Microspheres for Energy Applications." Micromachines 9, no. 8: 379.
The development of efficient luminescent systems, such as microcavities, solid state lasers, integrated optical amplifiers, optical sensors is the main topic in glass photonics. The building blocks of these systems are glass-ceramics activated by rare earth ions because they exhibit specific morphologic, structural and spectroscopic properties. Among various materials that could be used as nanocrystals to be imbedded in silica matrix, tin dioxide presents some interesting peculiarities, e.g. the presence of tin dioxide nanocrystals allows increase in both solubility and emission of rare earth ions. Here, we focus our attention on Er3+ - doped silica – tin dioxide photonic glass-ceramics fabricated by sol-gel route. Although the SiO2-SnO2:Er3+ could be fabricated in different geometrical systems: thin films, monoliths and planar waveguides we herein limit ourselves to the monoliths. The effective role of tin dioxide as luminescence sensitizer for Er3+ ions is confirmed by spectroscopic measurements and detailed fabrication protocols are discussed.
Lam Thi Ngoc Tran; Damiano Massella; Lidia Zur; Alessandro Chiasera; Stefano Varas; Cristina Armellini; Giancarlo C. Righini; Anna Lukowiak; Daniele Zonta; Maurizio Ferrari. SiO2-SnO2:Er3+ Glass-Ceramic Monoliths. 2018, 1 .
AMA StyleLam Thi Ngoc Tran, Damiano Massella, Lidia Zur, Alessandro Chiasera, Stefano Varas, Cristina Armellini, Giancarlo C. Righini, Anna Lukowiak, Daniele Zonta, Maurizio Ferrari. SiO2-SnO2:Er3+ Glass-Ceramic Monoliths. . 2018; ():1.
Chicago/Turabian StyleLam Thi Ngoc Tran; Damiano Massella; Lidia Zur; Alessandro Chiasera; Stefano Varas; Cristina Armellini; Giancarlo C. Righini; Anna Lukowiak; Daniele Zonta; Maurizio Ferrari. 2018. "SiO2-SnO2:Er3+ Glass-Ceramic Monoliths." , no. : 1.
Integrated optics is a branch of photonics allowing sophisticated and innovative solutions to many problems. As glasses exhibit many useful characteristics such as relatively low cost, excellent transparency, high threshold to optical damage, and easiness of doping with active and functional atoms and oxides, glass optical waveguides represent one of the simplest and most attractive building blocks over which photonic integrated circuits can be fabricated. Sol-gel technology has proved to be suitable to produce high-quality optical waveguides by single- and multilayer deposition. An accurate characterization of the produced waveguides is necessary in order to establish a correlation between the final properties and the parameters of the deposition process and hence to optimize the design and fabrication of the waveguides. Here a brief overview of the measurement techniques for sol-gel passive and active waveguides is presented.
Giancarlo C. Righini. Characterization of Sol-Gel Thin-Film Waveguides. Handbook of Sol-Gel Science and Technology 2018, 1565 -1593.
AMA StyleGiancarlo C. Righini. Characterization of Sol-Gel Thin-Film Waveguides. Handbook of Sol-Gel Science and Technology. 2018; ():1565-1593.
Chicago/Turabian StyleGiancarlo C. Righini. 2018. "Characterization of Sol-Gel Thin-Film Waveguides." Handbook of Sol-Gel Science and Technology , no. : 1565-1593.
We report on nonlinear optical effects on phoxonic cavities based on hollow whispering gallery mode resonators pumped with a continuous wave laser. We observed stimulated scattering effects such as Brillouin and Raman, Kerr effects such as degenerated and non-degenerated four wave mixing, and dispersive wave generation. These effects happened concomitantly. Hollow resonators give rise to a very rich nonlinear scenario due to the coexistence of several family modes.
Daniele Farnesi; Giancarlo C. Righini; Gualtiero Nunzi Conti; Silvia Soria. Efficient frequency generation in phoXonic cavities based on hollow whispering gallery mode resonators. Scientific Reports 2017, 7, srep44198 .
AMA StyleDaniele Farnesi, Giancarlo C. Righini, Gualtiero Nunzi Conti, Silvia Soria. Efficient frequency generation in phoXonic cavities based on hollow whispering gallery mode resonators. Scientific Reports. 2017; 7 (1):srep44198.
Chicago/Turabian StyleDaniele Farnesi; Giancarlo C. Righini; Gualtiero Nunzi Conti; Silvia Soria. 2017. "Efficient frequency generation in phoXonic cavities based on hollow whispering gallery mode resonators." Scientific Reports 7, no. 1: srep44198.
Glass photonics are widespread, from everyday objects around us to high-tech specialized devices. Among different technologies, sol–gel synthesis allows for nanoscale materials engineering by exploiting its unique structures, such as transparent glass-ceramics, to tailor optical and electromagnetic properties and to boost photon-management yield. Here, we briefly discuss the state of the technology and show that the choice of the sol–gel as a synthesis method brings the advantage of process versatility regarding materials composition and ease of implementation. In this context, we present tin-dioxide–silica (SnO2–SiO2) glass-ceramic waveguides activated by europium ions (Eu3+). The focus is on the photorefractive properties of this system because its photoluminescence properties have already been discussed in the papers presented in the bibliography. The main findings include the high photosensitivity of sol–gel 25SnO2:75SiO2 glass-ceramic waveguides; the ultraviolet (UV)-induced refractive index change (Δn ~ −1.6 × 10−3), the easy fabrication process, and the low propagation losses (0.5 ± 0.2 dB/cm), that make this glass-ceramic an interesting photonic material for smart optical applications.
Anna Lukowiak; Lidia Zur; Thi Ngoc Lam Tran; Marcello Meneghetti; Simone Berneschi; Gualtiero Nunzi Conti; Stefano Pelli; Cosimo Trono; B.N. Shivakiran Bhaktha; Daniele Zonta; Stefano Taccheo; Giancarlo C. Righini; Maurizio Ferrari. Sol–Gel-Derived Glass-Ceramic Photorefractive Films for Photonic Structures. Crystals 2017, 7, 61 .
AMA StyleAnna Lukowiak, Lidia Zur, Thi Ngoc Lam Tran, Marcello Meneghetti, Simone Berneschi, Gualtiero Nunzi Conti, Stefano Pelli, Cosimo Trono, B.N. Shivakiran Bhaktha, Daniele Zonta, Stefano Taccheo, Giancarlo C. Righini, Maurizio Ferrari. Sol–Gel-Derived Glass-Ceramic Photorefractive Films for Photonic Structures. Crystals. 2017; 7 (2):61.
Chicago/Turabian StyleAnna Lukowiak; Lidia Zur; Thi Ngoc Lam Tran; Marcello Meneghetti; Simone Berneschi; Gualtiero Nunzi Conti; Stefano Pelli; Cosimo Trono; B.N. Shivakiran Bhaktha; Daniele Zonta; Stefano Taccheo; Giancarlo C. Righini; Maurizio Ferrari. 2017. "Sol–Gel-Derived Glass-Ceramic Photorefractive Films for Photonic Structures." Crystals 7, no. 2: 61.
We present the possibility to tailor the optical properties of 1D photonic structures by using more than two materials and by clustering the high refractive index (hRI) layer in the structures. In particular, we show that: i) with a photonic crystal made of i different materials, the photonic band gap splits in i-1 bands; ii) with a proper choice of the layer thickness, disordered photonic structures made with a high number of layers show periodic transmission peaks; iii) when the size of the hRI layer clusters, randomly distributed within the low refractive index layers, follows a power law distribution, the total light transmission follows a sigmoidal function. Furthermore, we discuss the fabrication aspects to realize the above mentioned photonic structures. © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Alessandro Chiasera; Luigino Criante; Stefano Varas; Giuseppe Della Valle; Roberta Ramponi; Maurizio Ferrari; Ilka Kriegel; Michele Bellingeri; Davide Cassi; Giancarlo C. Righini; Francesco Scotognella. Tailoring the optical properties of one-dimensional (1D) photonic structures. Optical Components and Materials XIV 2017, 10100, 101001 .
AMA StyleAlessandro Chiasera, Luigino Criante, Stefano Varas, Giuseppe Della Valle, Roberta Ramponi, Maurizio Ferrari, Ilka Kriegel, Michele Bellingeri, Davide Cassi, Giancarlo C. Righini, Francesco Scotognella. Tailoring the optical properties of one-dimensional (1D) photonic structures. Optical Components and Materials XIV. 2017; 10100 ():101001.
Chicago/Turabian StyleAlessandro Chiasera; Luigino Criante; Stefano Varas; Giuseppe Della Valle; Roberta Ramponi; Maurizio Ferrari; Ilka Kriegel; Michele Bellingeri; Davide Cassi; Giancarlo C. Righini; Francesco Scotognella. 2017. "Tailoring the optical properties of one-dimensional (1D) photonic structures." Optical Components and Materials XIV 10100, no. : 101001.