0000000001192156

AUTHOR

Andrea Ando'

showing 25 related works from this author

Random Quasi-Phae-Matching in Tantalatio di Litio: origine del fenomeno, confronto tra propagazione bulk e guidata.

2011

We observe second harmonic generation via random quasi phase matching in a 1.5μm periodically poled lithium tantalate. The presence of a slab waveguides allows the comparison between bulk and guided wave configurations.

Settore ING-INF/02 - Campi Elettromagneticirandom quasi-phase-matching Tantalatio di Litio mark-to-space-ratio generazione di seconda armonica scambio protonico.Settore ING-INF/01 - Elettronica
researchProduct

Optical wireless GEO satellite-to-ground downlinks: rateless codes as solution for scintillation fading

2013

Scintillation fading can corrupt a satellite-to-ground optical wireless links with burst errors. Rateless codes, suitable for erasure channel, are able to eliminate or to reduce these communication errors. We analyzed the performances of three different rateless codes in a simulated Geo satellite-to-ground downlink.

Settore ING-INF/03 - TelecomunicazioniSettore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - ElettronicaFree Space Optics Rateless codes LT codes Raptor codes RaptorQ codes channel modeling
researchProduct

CulnSe2/Zn(S,O,OH) junction on Mo foil by electrochemical and chemical route for photovoltaic applications

2014

Electrodeposition is a convenient technique for the development of low cost materials for photovoltaic (PV) device processing. Using a single step electrodeposition route, several groups have fabricated CIS (CuInSe) and CIGS (CuInGaSe) films [1]. One of the most important requirements for successful application of one-step electrodeposition film formation, is the ability to control composition of the deposited films and to develop polycrystalline microstructures with a low surface roughness and high sintered density. In this preliminary work, CIS films were produced by single bath electrodeposition finding the optimal conditions in order to achieve a dense film with high crystallinity and u…

photovoltaicSSettore ING-IND/23 - Chimica Fisica ApplicataElectrodepositionSolar CellSettore ING-INF/02 - Campi ElettromagneticiThin FilmCulnSe2Settore ING-INF/01 - ElettronicaMo foil
researchProduct

Responsivity measurements of SiC photodiodes

2014

We investigated the technical features of three novel classes of 4H-SiC vertical Schottky UV photodiodes (henceforth, named SiC8, SiC10, SiC20) employing Ni2Si interdigitated strips whose pitch size is 8, 10 and 20 µm respectively [1] and based on the pinch-off surface effect.

sic photodiode uv light detector Schottky
researchProduct

Ethanol vapor optical sensors based on polystyrene opals infiltrated with hydrogel

2013

Optical sensing and sensornanostructured hydrogelphotonic crystalsSettore CHIM/07 - Fondamenti Chimici Delle TecnologieSettore ING-INF/01 - Elettronica
researchProduct

Responsivity measurements of SiC Schottky photodiodes

2014

We investigated the technical features of three novel classes of 4H-SiC vertical Schottky UV detectors employing Ni2Si interdigitated strips whose pitch size is 8, 10 and 20 µm, respectively, based on the pinch-off surface effect.

Settore ING-INF/02 - Campi Elettromagneticischottky photodiode uv sic detectorSettore ING-INF/01 - Elettronica
researchProduct

Optical turbulence measurements and channel modeling of an indoor Free Space Optics link (Abstract)

2014

optical turbulencetime-correlated Gamma-Gamma channel modelSettore ING-INF/03 - TelecomunicazioniFree Space OpticSettore ING-INF/01 - Elettronicaindoor link
researchProduct

Performance Investigation of Fountaine Codes on a Simulated Terrestrial Free Space Optical Channel

2012

Settore ING-INF/03 - TelecomunicazioniSettore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - ElettronicaFree Space Optics Channel Modeling Fountain Codes Raptor Codes RaptorQ Codes Luby Transform Codes Rateless Codes
researchProduct

Monitoring System of Passive Optical Networks with Remotely Power Supply of Optical Network Terminals

2011

In this paper, the authors, present last results on a low cost method to monitoring Passive-Optical-Network, which it uses Fiber-Bragg-Gratings and a modified Optical-Time-Domain-Reflectometer, and a remote power supply of Optical-Network-Terminals by a bivalent-use cable.

Settore ING-INF/01 - ElettronicaOptical monitoring passive optical network remote functionalities OTDR fiber Bragg gratings remote powering.
researchProduct

Correlated channel model for terrestrial Free Space Optics: performance analysis of rateless codes

2012

We describe a novel correlated channel model able to predict random temporal fluctuations of optical signal irradiance caused by scintillation. With regards to the same channel, we also report simulation results on the error mitigation performance of Luby-Transform and Raptor codes.

Settore ING-INF/03 - TelecomunicazioniFree Space Optics channel modeling Raptor codes RaptorQ codes LT codes rateless codesSettore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - Elettronica
researchProduct

All-Optical frequency Shifter in a Periodically Poled Lithium Tantalate Waveguide

2011

A frequency shifting device is fabricated and tested in a congruent Lithium Tantalate waveguide. Periodic poling for quasi-phase-matching and channels for operation in the near-infrared C-band were obtained, demonstrating a two-stage parametric conversion.

All-optical wavelength conversion second-harmonic generation difference-frequency generation ferroelectric crystals periodic poling Lithium Tantalate Lithium Niobate.Settore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - Elettronica
researchProduct

Correlated Channel Model for terrestrial Free Space Optics and project specifications evaluation of LT code in OOK modulation

2011

Free Space Optics is a wireless line-of-sight communication system able to offer good bandwidth performance as well as straightforward installation and relocation. So that it represents a modern technology that allow to realize large bandwidth communication particularly when it is not possible to employ physical cable or radio technologies. Examples of FSO applications are: wireless backaul, fiber backup, temporary links, metro network extension and last mile access[1]. FSO is based on optical signals propagation in air and that is why it suffers of impairments which depend on atmospheric conditions. In detail, FSO suffers of scattering (i. e. Rayleigh and Mie) losses, absorption and scinti…

Settore ING-INF/02 - Campi ElettromagneticiFree Space Optics FSO OOK LT code Luby Tranform Channel model correlation outage Gamma Gamma Rytov parameterSettore ING-INF/01 - Elettronica
researchProduct

Electro-Optical characterization of Silicon Carbide Schottky photodiodes

2014

Settore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - Elettronicasic schottky uv detector photodiode
researchProduct

Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks

2012

Settore ING-INF/03 - TelecomunicazioniFree Space Optics (FSO) technologies for satellite communications offer several advantages: wide bandwidth high rate capability immunity to electromagnetic interference and small equipment size. Thus they are suitable for inter-satellite links deep space communications and also for high data rate ground-to-satellite/satellite-to-ground communications. Nevertheless FSO links suffer impairments that cause power signal degradation at the receiver. Scattering and absorption cause power signal attenuations predictable by suitable deterministic models. Optical turbulence causes random irradiance fluctuations which can generate signal fading events and can thereby only be predicted by statistical models. Attenuation and fading events can corrupt FSO links and so it would be recommended to add mitigation error codes on the communication link. FSO channel can be described as an erasure channel: fading events can cause erasure errors. We have identified in rateless codes (RCs) a suitable solution to be employed in FSO links. RCs do not need feedback and they add a redundant coding on the source data that allows the receiver to recover the whole payload despite erasure errors. We implemented two different of rateless codes: Luby Transform (LT) and Raptor. We analyzed their performances on a simulated turbulent GEO FSO downlink (1 Gbps - OOK modulation) at a 106 μm wavelength and for different values of zenith angles. Assuming a plane-wave propagation and employing Hufnagel-Valley we modeled the downlink using: 1) a temporal correlated channel model based on Gamma-Gamma probability distribution and 2) an irradiance covariance function that we converted on a time function using Taylor frozen eddies hypothesis. Our new channel model is able to simulate irradiance fluctuations at different turbulence conditions as it will be shown in the full paper. We will also report performance results of LT and Raptor codes at overhead range varying between 0 and 50% and for different values of source packets.Settore ING-INF/01 - Elettronica
researchProduct

Fading mitigation coding techniques for space to ground free space optical communications (Euro Med Telco 2014)

2014

In this manuscript, a Geostationary satellite-toground Free Space Optics (FSO) downlink channel model has been implemented, which is able to predict temporal irradiance fluctuations caused by scintillation at a wide range of turbulence conditions and for different values of the zenith angle. In order to mitigate fading events that occur in FSO communications, we have also tested the performance of three different families of Rateless Codes (Luby Transform, Raptor and RaptorQ) into our model and found that RaptorQ is the best candidate to mitigate errors in FSO links.

Space-to- Ground FSO linkSettore ING-INF/03 - Telecomunicazionifading mitigationrateless codeSettore ING-INF/02 - Campi ElettromagneticiOptical Wireless Communicationtime-serieSettore ING-INF/01 - Elettronica
researchProduct

Cardiovascular parameters detection using a Photoplethismographic system

2016

We propose an innovative, cost-effective and easy to employ photoplethysmographic (PPG) system using Silicon Photomultipliers (SiPMs) sensors to measure cardiovascular parameters that can potentially represent markers for arterial stiffness

PPGCardiovascularSettore ING-INF/01 - ElettronicaPhotoplethismographic
researchProduct

Variazione della pressione sistolica e diastolica con la respirazione

2016

L’attività di ricerca in corso riguarda la possibilità di ricavare dati clinicamente significativi dai segnali ottici PPG (PhotoPletysmoGraphy). Il segnale PPG viene utilizzato per ricavare informazioni sul volume e sulla saturazione del sangue che interessa il distretto illuminato dalla luce IR (infrarosso) usata per l’analisi. Il volume di sangue contenuto nel segmento di arteria esaminato dipende dalla pressione e dal ciclo cardiaco, attraverso la rigidità dell’arteria.

pressione arteriosaluce infrarossa (IR)fotopletismografia (PPG)
researchProduct

FREE SPACE OPTICS LINKS AFFECTED BY OPTICAL TURBULENCE: CHANNEL MODELING, MEASUREMENTS AND CODING TECHNIQUES FOR ERROR MITIGATION

2014

FSO is an optical wireless line-of-sight communication system able to offer good broadband performance, electromagnetic interference immunity, high security, license-free operation, low power consumption, ease of relocation, and straightforward installation. It represents a modern technology, significantly functional when it is impossible, expensive or complex to use physical connections or radio links. Unfortunately, since the transmission medium in a terrestrial FSO link is the air, these communications are strongly dependent on various atmospheric phenomena (e.g., rain, snow, optical turbulence and, especially, fog) that can cause losses and fading. Therefore, in worst-case conditions, i…

optical turbulencescintillationrateless codes LT codes Raptor codes RaptorQ codes error mitigation fading mitigation.Free Space Optictime-serieSettore ING-INF/01 - Elettronica
researchProduct

Fading mitigation coding techniques for space to ground free space optical communications

2014

Settore ING-INF/03 - TelecomunicazioniSpace-to-Ground FSO links time-series rateless codefading mitigationSettore ING-INF/02 - Campi ElettromagneticiOptical Wireless CommunicationSettore ING-INF/01 - Elettronica
researchProduct

Luby Transform Performance Tests on Time-Correlated Channel Model for Geo Free Space Optics Downlinks

2012

Settore ING-INF/03 - TelecomunicazioniSettore ING-INF/01 - ElettronicaFree Space Optics Luby Transform Codes Rateless Codes Channel Modeling Geo Free Space Optics Downlinks
researchProduct

Second Harmonic Generation via Random Quasi-phase Matching in a Periodically Poled Lithium Tantalate Waveguide

2011

We observe second harmonic generation via random quasi phase matching in a 1.5μm periodically poled lithium tantalate. The presence of a slab waveguide allows the comparison between bulk and guided wave configurations.

Second Harmonic Generation Lithium Tantalate Random Quasi-phase Matching rQPM SHGSettore ING-INF/02 - Campi ElettromagneticiSettore ING-INF/01 - Elettronica
researchProduct

Light Soaking measurements on Ruthenium-based Dye Sensitized Solar Cells

2016

An interesting phenomenon occurring in Dye Sensitized Solar Cells (DSSCs) when exposed to an uninterrupted period of illumination is the so-called light soaking effect, which consists in the increase of the main electrical parameters of the cell, such as the photocurrent and the efficiency. Studying such an effect has noteworthy practical implications, ranging from the optimization of the manufacturing process to stability tests of DSSCs. In this paper, we present an experimental investigation on the performance variation, due to light soaking, of Ruthenium-based DSSCs.

solar cellphotovoltaicelectro-optical characterizationSettore ING-INF/02 - Campi ElettromagneticiDSSCSettore ING-INF/01 - Elettronica
researchProduct

CIGS Thin Film by One-Step Electrodeposition Deposition for Solar Cells

2013

Settore ING-IND/23 - Chimica Fisica ApplicataPhotovoltaics thin filmSettore ING-INF/01 - Elettronica
researchProduct

CuInSe2/Zn(S,O,OH) junction by electrochemical and chemical route for photovoltaic applications (GE 2014)

2014

Electrodeposition is a convenient technique for the development of low cost materials for photovoltaic (PV) device processing. Using a single step electrodeposition route, several groups have fabricated CIS (CuInSe) and CIGS (CuInGaSe) films. One of the most important requirements for successful application of one-step electrodeposition film formation is the ability to control composition of the deposited films and to develop polycrystalline microstructures with a low surface roughness and high sintered density.

solar cellphotovoltaicSettore ING-IND/23 - Chimica Fisica Applicatathin filmCIGSSettore ING-INF/01 - Elettronica
researchProduct

Optical turbulence measurements and channel modeling of an indoor Free Space Optics link (Versione estesa)

2014

In this work, we propose an indoor experimental set-up able to generate several optical turbulence conditions in a Free Space Optics link. Using this set-up, we prove the effectiveness of an irradiance time-series generator based on the Gamma-Gamma model and able to predict the irradiance fluctuations at the receiver, under both weak and moderate turbulence conditions.

optical turbulenceSettore ING-INF/03 - TelecomunicazioniFree Space OpticGamma-Gamma modeltime-serieSettore ING-INF/01 - Elettronica
researchProduct