Past Events

Seminar Announcement: Michael Scalora

posted Sep 17, 2018, 5:12 AM by Stefano Varas   [ updated Sep 17, 2018, 5:13 AM ]

Announcement
Thursday, 13 September 2018, 11:30
Sala Grande Palazzina C via alla Cascata 56/C

"Optics at the NANOSCALE: An Attempt at a Comprehensive Analysis of Surface Harmonic Generation...and more"

Michael Scalora
Charles M. Bowden Research Facility, AMRDEC, US Army RDECOM,
RDMR-WDS-R, Bldg. 7804 Redstone Arsenal, AL 35898

Abstract
We present a study of linear and nonlinear optical effects that occur when light interacts with metallic surfaces and generic structures with nanometer-scale features. Our model suggests that the nonlinear optical analysis of metals, conductive oxides, nano-antennas, meta-surfaces, etc. should be performed by including nonlocal effects (viscosity and pressure of free electrons); linear and nonlinear contributions of bound (inner-core) electrons to the dielectric constant; linear and nonlinear quantum tunneling currents if gaps between nanoparticles is on the nanometer and sub-nanometer scale; and conditions generally reflective of discontinuous free electron densities. We use a modified hydrodynamic model to evaluate harmonic generation from a gold mirror, where epsilon- near-zero conditions may be found and exploited, and from semiconductors like GaAs and GaP.

Seminar Announcement: Angela Seddon

posted Sep 13, 2018, 12:44 AM by Stefano Varas   [ updated Sep 13, 2018, 12:44 AM ]

Announcement
Tuesday, 11 September 2018, 15:00
Sala Grande Palazzina B via alla Cascata 56/C

"Towards rare earth doped mid-infrared fibre lasers"

Angela Seddon
Chair of Inorganic Materials. Head of Mid-Infrared Glasses Group, GGIEMR, Faculty of Engineering.
University of Nottingham, UK

Abstract
The progress made towards mid-infrared (MIR) fibre lasers will be described. Despite ongoing work since the late 1990s, fibre lasing above 4 microns wavelength in the MIR region has not yet been demonstrated. Current modelling has not uncovered all of the reasons for this lack of success. Photoluminescence and long photoluminescent lifetimes have been observed for rare earth ions such as Dy(III), Pr(III), Tb(III) and Ce(III) doped into selenide chalcogenide-glasses. Long PL lifetimes in small-core fibre will be shown. The underlying problem of impurities in the glass host causing extrinsic absorption has been modelled to reveal the true rare earth ion absorption cross-sections. The possibility of these unwanted impurities causing non-radiative depopulation of rare earth ion excited states will be addressed. In addition, the possibility of interference in the excited state dynamics of rare earth ions of the WAT (weak absorption tail) will also be introduced.

Seminar Announcement: Patrice Salzenstein

posted Sep 13, 2018, 12:43 AM by Stefano Varas   [ updated Sep 13, 2018, 12:43 AM ]

Announcement
Tuesday, 11 September 2018, 10:30
Sala Grande Palazzina C via alla Cascata 56/C

"Brillouin light scattering for the characterization of bulk and surface elastic waves"

Patrice Salzenstein
Institut FEMTO-ST 15B Avenue des Montboucons 25030 BESANÇON CEDEX,
France

Abstract
Brillouin scattering reveals acoustic or spin-wave frequencies in the microwave frequency domain. Brillouin light scattering (BLS) setup deals with the detection and analysis of laser light scattered by fluctuations of refracting index in a medium. It consists in analysis of the refracted light emitted by a material. Tandem Fabry–Perot interferometer produces peaks shifted from the frequency of the laser to characteristic frequencies depending on the material. As a way of calibration, we can characterized different bulk materials such as for example glass, PMMA, nylon, polypropylene, Lithium-aluminosilicate glass ceramic or thin layers. From BLS we can deduce parameters of the material like phase velocity of transverse and longitudinal waves.

Seminar Announcement: Alessandro Lauria

posted Sep 5, 2018, 8:07 AM by Stefano Varas   [ updated Sep 5, 2018, 8:07 AM ]

Announcement
Monday, 3 September 2018, 10:30
Sala Grande Palazzina B via alla Cascata 56/C

"Structure-function relationship in optical nanomaterials"

Alessandro Lauria
Laboratory for Multifunctional Materials, Swiss Federal Institute of Technology (ETH Zürich),
Zürich, Switzerland

Abstract
Several properties of nanomaterials are related to their crystallinity, size and composition. Many of these structural parameters can be pre-determined through chemical choices operated during their synthesis. Moreover, the surface features of nanoparticles govern their interaction with the environment, setting the bases for their implementation into functional composites and biological systems. I will discuss some of the chemical parameters which enable control over optical properties of nanoparticles, as well as on their further processing toward optical materials at the macroscale.

SMS 2018

posted Aug 2, 2018, 1:47 AM by Stefano Varas


7th International Summer School on Smart Materials & Structures

This year the ​​International Summer School on Smart Materials & Structures is held in Trento, Italy, in the period July 25-28, 2018. The scope of the school is to provide an overview of smart technologies from a cross-disciplinary perspective with special focus on optical sensors, wireless sensor networks, smart materials, nano- and micro-technologies, NDT evaluation and decision making.

The school lecturers include:
Branko Glisic, Princeton University, USA;
Dionisio Bernal, Northeastern University, USA;
Wieslaw Ostachowicz, Polish Academy of Sciences, Poland;
Marcus Perry, University of Strathclyde, UK;
Yang Wang, Georgia Institute of Technology, USA

You can find more information on the school program at: http://event.unitn.it/smartstructures2018

Who should attend
The school addresses graduate students and postdocs pursuing research in the field of smart materials and structures.

Registration
The registration fee is €400.00. Register by July 1, 2018, at http://events.unitn.it/en/smartstructures2017/registration

Scholarships
The school offers 5 scholarships covering the registration fee ​​to support the participation of international students. Scholarship application deadline is June 17, 2018. To apply, please visit the school website at http://event.unitn.it/smartstructures2018

Contact
For any further help needed, please contact me or visit the school website at http://event.unitn.it/smartstructures2018

Seminar Announcement: Li-Fi Demonstration

posted Aug 2, 2018, 1:45 AM by Stefano Varas   [ updated Aug 2, 2018, 1:45 AM ]

Announcement
Wednesday, 1 August 2018, 11:00
Sala Grande Palazzina B via alla Cascata 56/C

"Li-Fi Demonstration"

Giulia Bridi and Gianluca Nardon
Leonardo Da Vinci Scientific Highschool Students

Abstract
When the telegraphy was invented, It was a breakthrough technology in terms of fast and secure communication. The Morse System used in the telegraphy can be considered among the first demonstrations of the binary system which is also the main working principle of modern computers. Further developments led to the radio frequency and wireless technologies to take the place of telegraphy and they are today’s most popular communication technologies.

Li-Fi (Light Fidelity) is a new and promising technology which offers the use of Light instead of Radio Frequency. It opens the way to faster and more secure communication.

CIMTEC 2018

posted Jun 19, 2018, 4:50 AM by Stefano Varas


Symposium CL
Inorganic Materials Systems for Advanced Photonics

The fruitful exploitation of optical ceramics and glasses and related photonic structures and devices as crucial pivots for the development of several enabling technologies provides a large spectrum of functionalities that allow us to face successfully socio- economic challenges in many fields going from energy production and saving to efficient and clean industrial cycles, from environmental protection to fast efficient novel communication systems, from structural monitoring to quantum technologies and to healthcare applications.
This Symposium, that follows the several ones on similar subject held at previous CIMTEC conferences, is to provide latest insights on fabrication, characterization and exploitation of photonic structures based on ceramics (oxides, oxynitrides, fluorides, sulphides, chalcogenides, etc...) inorganic non-metallic glasses, glass- ceramics, and ceramic/metal and glass/metal combinations in the form of nanostructured, bulk and graded materials and coatings, fibres, thin films, superlattices and other small confined systems, nanomaterials, nanocomposites and functional nanoparticles.
Focus will be on theory, modelling and simulation of materials and processes, green and advanced fabrication protocols (self assembly, particle beams, light irradiation, micromachining, colloidal processing...) and up-to-date characterization of structure, non-linear optical properties, tunability, nanosize effects etc. of novel inorganic photonic materials systems for light generation, detection, and manipulation including e.g. luminescent and laser materials, smart optical fibres, active plasmonic heterostructures, novel confined nano-micro structures etc. covering the UHV-IR electromagnetic spectrum.
Contributions from Academia and industry on upgraded or novel application and prospective new approaches to photonic-based technologies are also firmly encouraged.

http://2018.cimtec-congress.org/symposium_cl

Seminar Announcement: Tindaro Ioppolo

posted Jun 14, 2018, 6:54 AM by Stefano Varas   [ updated Jun 14, 2018, 6:55 AM ]

Announcement
Wednesday, 13 June 2018, 10:30
Sala Grande Palazzina B via alla Cascata 56/C

"Magnetostrictive and electrostrictive optical cavities"

Tindaro Ioppolo
Bobby Lyle School of Engineering, Department of Mechanical Engineering,
Southern Methodist University Dallas, Texas, USA

Abstract
The effect of electric and magnetic field on the optical resonances of electrostrictive and magnetostrictive optical resonators is presented. The electrostrcitve or the magnetostrictive effect is the elastic deformation of a solid when subject to an electric or magnetic field. The optical resonator has a spherical shape and a diameter of a few hundred micrometers. The resonator is fabricated using a polymeric matrix made of Polyvinyl Chloride (PVC) Plastisol with embedded magnetically polarizable micro-particles. When the optical resonator is exposed to an external electric or magnetic field, the morphology (radius and refractive index) of the resonator is perturbed by the magnetic or electric forces acting on it, leading to a shift of the optical resonances also known as whispering gallery modes (WGM). In this study, the effect of a static and harmonic magnetic and electric field on the optical mode shift is investigated. The optical resonances obtained with the PVC plastisol resonator showed a quality factor of ~106. The optical shift in turn is monitored and related to the external effect. Sensors based on this concept will be presented for different applications.

Seminar Announcement: Tindaro Ioppolo

posted Jun 14, 2018, 6:54 AM by Stefano Varas   [ updated Jun 14, 2018, 6:54 AM ]

Announcement
Tuesday, 12 June 2018, 10:30
Sala Grande Palazzina B via alla Cascata 56/C

"All photonic microsensors based on whipering gallery mode resonators"

Tindaro Ioppolo
Bobby Lyle School of Engineering, Department of Mechanical Engineering,
Southern Methodist University Dallas, Texas, USA

Abstract
A Spherical and dome shaped resonators made of different polymers are used as a sensing element for mechanical applications. The sensing mechanism is based on the propagation of whispering gallery waves that are traveling into optical cavities. Tethered and untethered sensors will be presented. Tethered sensors are mainly spherical micro cavities that are coupled evanescently to a single mode optical fiber. The optical fiber serves as input output port to excite and interrogate the optical modes. Untethered sensors are essentially spherical or dome shaped microscale lasers that are excited using an external light source. The emission spectrum of the microscale laser is observed using a spectrometer. This last configuration allows for a remote excitation and interrogation of the optical modes. In both configurations, a change in the morphology of the micro cavity due to an external effect leads to a shift in its optical modes. The optical shift in turn is monitored and related to the external effect. Sensors based on this concept will be presented for different applications.

Seminar Announcement: Jonathan Bradley

posted Jun 14, 2018, 6:53 AM by Stefano Varas   [ updated Jun 14, 2018, 6:54 AM ]

Announcement
Tuesday, 12 June 2018, 15:00
Sala Grande Palazzina B via alla Cascata 56/C

"Microlasers on silicon chips based on high-Q rare-earth-doped aluminum oxide micro-trench resonators"

Jonathan Bradley
Barber-Gennum Chair in Information Technology, Department of Engineering Physics,
McMaster University

Abstract
We report on rare-earth-doped microcavity lasers monolithically integrated on silicon nanophotonic chips. The microlasers are based on a novel silicon-photonics- compatible and high-Q microresonator design, which includes a silicon dioxide trench filled with rare-earth-doped aluminum oxide and a co-integrated silicon nitride bus waveguide. In passive (undoped) microresonators we measure internal quality factors > 106 at a wavelength of 1.5 µm. In ytterbium, erbium, and thulium- doped microcavities with diameters ranging from 80 to 200 µm we show lasing at 1.0, 1.5 and 1.9 µm, respectively. We observe sub-milliwatt lasing thresholds, approximately 10 times lower than previously demonstrated in monolithic rare- earth-doped lasers on silicon. The entire fabrication process, which includes post- processing deposition of the gain medium, is silicon-compatible and allows for integration of such lasers within integrated silicon photonic microsystems. Applications of such rare earth microlasers in integrated microsystems for communications and sensing will be discussed.

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