Search results for "campi elettromagnetici"

showing 10 items of 155 documents

Framework for complex quantum state generation and coherent control based on on-chip frequency combs

2018

Integrated frequency combs introduce a scalable framework for the generation and manipulation of complex quantum states (including multi-photon and high-dimensional states), using only standard silicon chip and fiber telecommunications components.

010302 applied physicsQuantum opticsPhysicsbusiness.industryFiber (mathematics)Electronic Optical and Magnetic MaterialPhysics::OpticsSettore ING-INF/02 - Campi ElettromagneticiQuantum information processingSettore ING-INF/01 - Elettronica01 natural sciences010309 opticsMechanics of MaterialsCoherent controlQuantum state0103 physical sciencesScalabilitySilicon chipOptoelectronicsCoherent statesbusinessFrontiers in Optics / Laser Science
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Generation and Coherent Control of Pulsed Quantum Frequency Combs

2018

We present a method for the generation and coherent manipulation of pulsed quantum frequency combs. Until now, methods of preparing high-dimensional states on-chip in a practical way have remained elusive due to the increasing complexity of the quantum circuitry needed to prepare and process such states. Here, we outline how high-dimensional, frequency-bin entangled, two-photon states can be generated at a stable, high generation rate by using a nested-cavity, actively mode-locked excitation of a nonlinear micro-cavity. This technique is used to produce pulsed quantum frequency combs. Moreover, we present how the quantum states can be coherently manipulated using standard telecommunications…

0301 basic medicineDensity matrixOptics and PhotonicsPhotonGeneral Chemical EngineeringSettore ING-INF/01 - ElettronicaGeneral Biochemistry Genetics and Molecular Biology03 medical and health sciencesEngineering0302 clinical medicineQuantum stateQuantum DotsQuantumQCQuantum opticsPhysicsGeneral Immunology and Microbiologybusiness.industryGeneral NeuroscienceNonlinear opticsSettore ING-INF/02 - Campi Elettromagnetici030104 developmental biologyCoherent controlQuantum optics Integrated photonic devices Mode-locked lasers Nonlinear optics Four-wave mixing Frequency combs High- dimensional statesFrequency domainOptoelectronicsbusiness030217 neurology & neurosurgeryJournal of Visualized Experiments
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Finite-Size and Illumination Conditions Effects in All-Dielectric Metasurfaces

2022

Dielectric metasurfaces have emerged as a promising alternative to their plasmonic counterparts due to lower ohmic losses, which hinder sensing applications and nonlinear frequency conversion, and their larger flexibility to shape the emission pattern in the visible regime. To date, the computational cost of full-wave numerical simulations has forced the exploitation of the Floquet theorem, which implies infinitely periodic structures, in designing such devices. In this work, we show the potential pitfalls of this approach when considering finite-size metasurfaces and beam-like illumination conditions, in contrast to the typical infinite plane-wave illumination compatible with the Floquet t…

All-dielectric metasurfaces BIC Multipolar decomposition T-matrixComputer Networks and CommunicationsHardware and ArchitectureControl and Systems Engineeringall-dielectric metasurfaces; multipolar decomposition; T-matrix; BICSignal ProcessingPhysics::OpticsSettore ING-INF/02 - Campi ElettromagneticiElectrical and Electronic EngineeringElectronics
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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
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Passive RFID Strain-Sensor Based on Meander-Line Antennas

2011

The processing of backscattered signals coming from RFID tags is potentially useful to detect the physical state of the tagged object. It is here shown how to design a completely passive UHF RFID sensor for strain monitoring starting from a flexible meander-line dipole whose shape factor and feed section are engineered to achieve the desired sensing resolution and dynamic range. This class of devices is low-cost, promises sub-millimeter resolution and may found interesting applications in the Structural Health Monitoring of damaged structures and vehicles as well as during extreme and adverse events.

BackscatterComputer sciencebusiness.industryElectrical engineeringSettore ING-INF/02 - Campi Elettromagneticilaw.inventionDipoleRFID sensor SHMUltra high frequencylawDipole antennaStructural health monitoringSensitivity (control systems)Electrical and Electronic EngineeringbusinessElectrical impedanceStrain gauge
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Error mitigation using RaptorQ codes in an experimental indoor free space optical link under the influence of turbulence

2015

In free space optical (FSO) communications, several factors can strongly affect the link quality. Among them, one of the most important impairments that can degrade the FSO link quality and its reliability even under the clear sky conditions consists of optical turbulence. In this work, the authors investigate the generation of both weak and moderate turbulence regimes in an indoor environment to assess the FSO link quality. In particular, they show that, due to the presence of the turbulence, the link experiences both erasure errors and packet losses during transmission, and also compare the experimental statistical distribution of samples with the predicted Gamma Gamma model. Furthermore,…

Computer scienceOptical linkReliability (computer networking)Optical linksTelecommunication network reliabilityRytov variance valueSettore ING-INF/01 - ElettronicaTelecomunicacióRaptorQ codesRedundancy (information theory)Indoor free space optical linkFSO communicationsStatisticsTEORIA DE LA SEÑAL Y COMUNICACIONESRedundancy (engineering)Gamma Gamma modelrateless codeElectrical and Electronic Engineeringpacket error rate (PER)Error-free transmissionNetwork packetbusiness.industrySettore ING-INF/03 - TelecomunicazioniSettore ING-INF/02 - Campi ElettromagneticiÒpticaComputer Science ApplicationsTransmission (telecommunications)Bit error rateErasureProbability distributionFree Space Optical (FSO) communicationTelecommunicationsbusinessOptical turbulenceFSO link reliabilityindoor linkError mitigation
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The RFID technology for neurosciences: feasibility of limbs' monitoring in sleep diseases.

2009

This contribution investigates the feasibility of the passive UHF RF identification technology for the wireless monitoring of human body movements in some common sleep disorders by means of passive tags equipped with inertial switches. Electromagnetic and mechanical models as well as preliminary experimentations are introduced to analyze all the significant issues concerning the required power, the tag antenna design, the read distance, and the expected biosignals collected by the interrogation device.

Computer scienceRemote patient monitoringRadio WavesPolysomnographytag antennaRFID sensor Human health monitoringAccelerometerRF identification (RFID)MotionRestless Legs SyndromemedicineWirelessHumansTelemetryaccelerometer; RF identification (RFID); sensor network; sleep disorder; tag antennaElectrical and Electronic Engineeringsensor networksleep disorderSleep disorderbusiness.industrySettore ING-INF/02 - Campi ElettromagneticiExtremitiesGeneral MedicineModels Theoreticalmedicine.diseaseComputer Science ApplicationsNocturnal Myoclonus SyndromeaccelerometerRadio frequencySleep (system call)TelecommunicationsbusinessWireless sensor networkComputer hardwareAlgorithmsBiotechnologyIEEE transactions on information technology in biomedicine : a publication of the IEEE Engineering in Medicine and Biology Society
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Humidity Sensing by Polymer-Loaded UHF RFID Antennas

2012

Passive ultra high-frequency radio frequency identification tags, besides item labeling, are also able to exploit capability to sense the physical state of the tagged object as well as of the surrounding environment. Here, a new family of polymer-doped tags are proposed and fully characterized for the detection of ambient humidity. A sensitive chemical species based on PEDOT:PSS is used to load a shaped slot, carved into a folded-like patch tag. The communication and sensing capabilities of the resulting radio-sensor are investigated by means of simulation and measurements that show how to control and balance above opposite requirements by a proper deposition of the sensitive material. The …

Computer sciencebusiness.industryElectrical engineeringHumidityRFIDsensor antennaSettore ING-INF/02 - Campi ElettromagneticiSense (electronics)Microstrip antennaUltra high frequencyPEDOT:PSSRadio-frequency identificationDeposition (phase transition)Electrical and Electronic EngineeringbusinessInstrumentation
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Third-harmonic light polarization control in magnetically resonant silicon metasurfaces

2021

Nonlinear metasurfaces have become prominent tools for controlling and engineering light at the nanoscale. Usually, the polarization of the total generated third harmonic is studied. However, diffraction orders may present different polarizations. Here, we design an high quality factor silicon metasurface for third harmonic generation and perform back focal plane imaging of the diffraction orders, which present a rich variety of polarization states. Our results demonstrate the possibility of tailoring the polarization of the generated nonlinear diffraction orders paving the way to a higher degree of wavefront control.

DiffractionEBLSiliconthird harmonic wave front control diffraction orders polarizationFOS: Physical scienceschemistry.chemical_elementPhysics::Optics02 engineering and technology01 natural sciences010309 opticsQuality (physics)Optics0103 physical sciencesnonlinear diffractionWavefrontPhysicsbusiness.industryNonlinear opticsSettore ING-INF/02 - Campi Elettromagnetici021001 nanoscience & nanotechnologyPolarization (waves)Atomic and Molecular Physics and OpticsNonlinear systemmetasurfaceCardinal pointchemistry0210 nano-technologybusinessthird harmonicOptics (physics.optics)Physics - Optics
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Wideband THz time domain spectroscopy based on optical rectification and electro-optic sampling

2013

We present an analytical model describing the full electromagnetic propagation in a THz time-domain spectroscopy (THz-TDS) system, from the THz pulses via Optical Rectification to the detection via Electro Optic-Sampling. While several investigations deal singularly with the many elements that constitute a THz-TDS, in our work we pay particular attention to the modelling of the time-frequency behaviour of all the stages which compose the experimental set-up. Therefore, our model considers the following main aspects: (i) pump beam focusing into the generation crystal; (ii) phase-matching inside both the generation and detection crystals; (iii) chromatic dispersion and absorption inside the c…

DiffractionTA1501Optical rectificationComputer scienceTerahertz radiationTerahertz radiationPhysics::OpticsSettore ING-INF/01 - ElettronicaArticleCrystalElectro-optic samplingOptical rectificationOpticsSampling (signal processing)Dispersion (optics)Thz time domain spectroscopyWidebandSpectroscopyAbsorption (electromagnetic radiation)Multidisciplinarybusiness.industrySettore ING-INF/02 - Campi ElettromagneticiQC0450Terahertz detectorsTerahertz sourcebusinessTelecommunicationsBeam (structure)
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