0000000000011128

AUTHOR

Ashwani Kumar

showing 14 related works from this author

10 Gb/s transmission and thermo-optic resonance tuning in silicon-plasmonic waveguide platform

2011

The first system-level experimental results of hybrid Si-DLSPP structures incorporated into a SOI chip are reported. We demonstrate over 7nm thermo-optical tuning of a Si-Plasmonic racetrack-resonator and verify error-free 10Gb/s transmission through 60um Si-Plasmonic waveguide.

Materials scienceSiliconbusiness.industryPhotonic integrated circuitSilicon on insulatorchemistry.chemical_elementChiplaw.inventionOpticsTransmission (telecommunications)chemistrylawOptical cavityOptoelectronicsbusinessWaveguidePlasmon
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Active Plasmonics in True Data Traffic Applications: Thermo-Optic On/Off Gating Using a Silicon-Plasmonic Asymmetric MachZehnder Interferometer

2012

We present the first system-level demonstration of an active plasmonic device in 10-Gb/s data traffic conditions. An asymmetric silicon-plasmonic Mach-Zehnder interferometer with dielectric-loaded plasmonic waveguides serving as the electrically controlled arms, operates as thermo-optic ON/OFF gating element with 2.8-mu s response time and 10.8-mW power consumption. We present the first system-level demonstration of an active plasmonic device in 10-Gb/s data traffic conditions. An asymmetric silicon-plasmonic Mach-Zehnder interferometer with dielectric-loaded plasmonic waveguides serving as the electrically controlled arms, operates as thermo-optic ON/OFF gating element with 2.8-mu s respon…

Siliconchemistry.chemical_elementPhysics::Optics02 engineering and technologyGatingMach–Zehnder interferometerON-INSULATOR01 natural sciencesOptical switch010309 optics020210 optoelectronics & photonicsOptics0103 physical sciences0202 electrical engineering electronic engineering information engineeringSWITCHElectrical and Electronic EngineeringPlasmonPhysicsbusiness.industryResponse timeAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsInterferometrychemistryOptoelectronicsPhotonicsbusiness
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Power monitoring in dielectric-loaded surface plasmon-polariton waveguides

2011

We report on propagating mode power monitoring in dielectric-loaded surface plasmon-polariton waveguides (DLSPPWs) by measuring the resistance of gold stripes supporting the DLSPPW mode propagation. Inevitable absorption of the DLSPPW mode in metal causes an increase in the stripe temperature and, thereby, in its resistance whose variations are monitored with an external Wheatstone bridge being accurately balanced in the absence of radiation in a waveguide. The investigated waveguide configuration consists of a 1-µm-thick and 10-µm-wide polymer ridges tapered laterally to a 1-µm-wide ridge placed on a 50-nm-thin and 4-µm-wide gold stripe, all supported by a magnesium fluoride substrate. Usi…

Magnesium fluorideMaterials scienceWheatstone bridgebusiness.industrySurface plasmonPhotonic integrated circuitBiasingSurface plasmon polaritonAtomic and Molecular Physics and Opticslaw.inventionchemistry.chemical_compoundOpticschemistrylawbusinessAbsorption (electromagnetic radiation)Waveguide
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Elective surgery system strengthening: development, measurement, and validation of the surgical preparedness index across 1632 hospitals in 119 count…

2022

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: The 2015 Lancet Commission on global surgery identified surgery and anaesthesia as indispensable parts of holistic health-care systems. However, COVID-19 exposed the fragility of planned surgical services around the world, which have also been neglected in pandemic recovery planning. This study aimed to develop and validate a novel index to support local elective surgical system strengthening and address growing backlogs. Methods: First, we performed an international consultation through a four-stage consensus process to develop a multidomain index for hospital-level assess…

MaleHealth system resilience.*COVID-19/epidemiologySocial SciencesSağlık BilimleriGlobal HealthFundamental Medical SciencesClinical Medicine (MED)AnaesthesiasurgeryTIP GENEL & DAHİLİnisu navedene ključne riječiElective backlogMedicine and Health SciencesTOOLKlinik Tıp (MED)610 Medicine & healthMEDICINE GENERAL & INTERNAL11 Medical and Health SciencesKlinik Tıpsurgery; global surgery; health-care systemCovid19NIHR Global Health Unit on Global SurgeryGeneral MedicineHospitalsHospital preparedneTıphealth-care systemElective Surgical ProceduresHEALTH SYSTEMS*PandemicsMedicineFemaleLife Sciences & BiomedicineHumanHälso- och sjukvårdsorganisation hälsopolitik och hälsoekonomiTemel Tıp Bilimleri610 Medicine & healthglobal surgeryGenel TıpCAPACITYCOVIDSurg CollaborativeHospitalMedicine General & InternalGeneral & Internal MedicineHealth SciencesHumansPandemicsScience & TechnologyElective Surgical ProcedurePandemicKirurgiPlanned surgeryCOVID-19Health Care Service and Management Health Policy and Services and Health EconomyCLINICAL MEDICINESettore MED/18Settore MED/18 - Chirurgia Generaleelective surgeryHospital assessmentSystems strengtheningSurgeryHuman medicineMETHODOLOGY[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
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Active plasmonics in WDM traffic switching applications

2012

With metal stripes being intrinsic components of plasmonic waveguides, plasmonics provides a "naturally" energy-efficient platform for merging broadband optical links with intelligent electronic processing, instigating a great promise for low-power and small-footprint active functional circuitry. The first active Dielectric-Loaded Surface Plasmon Polariton (DLSPP) thermo-optic (TO) switches with successful performance in single-channel 10 Gb/s data traffic environments have led the inroad towards bringing low-power active plasmonics in practical traffic applications. In this article, we introduce active plasmonics into Wavelength Division Multiplexed (WDM) switching applications, using the …

Optical fiberComputer scienceTRANSMISSIONTransducersSilicon on insulator02 engineering and technology01 natural sciencesMultiplexingArticlelaw.invention010309 opticsMetalPOWER THERMOOPTICAL SWITCHlawWavelength-division multiplexing0103 physical sciencesElectronic engineeringFiber Optic TechnologySurface plasmon resonanceSILICON-ON-INSULATORPlasmonElectronic circuitMultidisciplinaryCHIPReproducibility of ResultsEquipment DesignSurface Plasmon ResonancePERFORMANCE021001 nanoscience & nanotechnologyChipSurface plasmon polaritonInterferometryWavelengthInterferometryTransducerPlasmonic waveguidevisual_artTelecommunicationsvisual_art.visual_art_mediumPOLARITON WAVE-GUIDES0210 nano-technology
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0.48Tb/s (12x40Gb/s) WDM transmission and high-quality thermo-optic switching in dielectric loaded plasmonics

2012

We demonstrate Wavelength Division Multiplexed (WDM)-enabled transmission of 480Gb/s aggregate data traffic (12x40Gb/s) as well as high-quality 1x2 thermo-optic tuning in Dielectric-Loaded Surface Plasmon Polariton Waveguides (DLSPPWs). The WDM transmission characteristics have been verified through BER measurements by exploiting the heterointegration of a 60 mu m-long straight DLSPPW on a Silicon-on-Insulator waveguide platform, showing error-free performance for six out of the twelve channels. High-quality thermo-optic tuning has been achieved by utilizing Cycloaliphatic-Acrylate-Polymer as an efficient thermo-optic polymer loading employed in a dual-resonator DLSPPW switching structure, …

Materials scienceON-CHIP02 engineering and technology01 natural sciencesOptical switchlaw.invention010309 opticsOpticslawWavelength-division multiplexing0103 physical sciencesGOLDPlasmonSCALEExtinction ratiobusiness.industryPhotonic integrated circuitCOMPONENTSTemperatureOptical DevicesSignal Processing Computer-AssistedEquipment DesignSurface Plasmon Resonance021001 nanoscience & nanotechnologySurface plasmon polaritonAtomic and Molecular Physics and OpticsNETWORKSEquipment Failure AnalysisTransmission (telecommunications)TelecommunicationsPOLARITON WAVE-GUIDES0210 nano-technologybusinessWaveguide
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Imidazolium Based Ionic Liquids: A Promising Green Solvent for Water Hyacinth Biomass Deconstruction.

2018

Water hyacinth (WH) is a troublesome aquatic weed of natural and artificial water bodies of India and other tropical countries and causing severe ecological problems. The WH biomass is low in lignin content and contains high amount of cellulose and hemicellulose, making it suitable material for conversion into liquid fuels for energy production. This study highlighted that, how different imidazolium based ionic liquids (ILs) [1-alkyl-3-methylimidazolium bromide, [Cnmim]Br (n = 2, 4, 6, 8, and 10)] with tunable properties can be employed for the degradation of WH biomass. Different characterizations techniques, such as XRD, FT-IR, SEM, and DSC are used to unravel the interplay between ILs an…

0106 biological sciences020209 energyLignocellulosic biomassBiomass02 engineering and technology01 natural scienceslcsh:Chemistryionic liquidschemistry.chemical_compoundHydrolysisBromide010608 biotechnology0202 electrical engineering electronic engineering information engineeringLigninHemicelluloseCelluloselignocellulosic biomassOriginal ResearchGeneral Chemistrypretreatmentcrystallinity indexChemistrylcsh:QD1-999chemistryhydrolysisIonic liquidwater hyacinthNuclear chemistryFrontiers in chemistry
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SARS-CoV-2 infection and venous thromboembolism after surgery: an international prospective cohort study

2021

SARS-CoV-2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri-operative or prior SARS-CoV-2 were at further increased risk of venous thromboembolism. We conducted a planned sub-study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 da…

Malepulmonary embolismInternationalitySettore MED/18 - CHIRURGIA GENERALEDeep veinVascular damage Radboud Institute for Health Sciences [Radboudumc 16]infectious diseasesCardiovascularSARS‐CoV‐2surgeryCOVID-19 ; SARS-CoV-2 ; deep vein thrombosis ; pulmonary embolism ; venous thromboembolismCohort StudiesPostoperative ComplicationsAnesthesiologyMedicine and Health SciencesProspective Studies610 Medicine & healthProspective cohort studyLung11 Medical and Health SciencesConfoundingHematologyMiddle AgedThrombosis17 Psychology and Cognitive SciencesCOVID-19; deep vein thrombosis; pulmonary embolism; SARS-CoV-2; venous thromboembolismPulmonary embolismCOVID-19; SARS-CoV-2; deep vein thrombosis; pulmonary embolism; venous thromboembolism.medicine.anatomical_structureCohortCOVID-19/complicationsPostoperative Complications/etiologyOriginal ArticleFemalePatient SafetyLife Sciences & BiomedicineCOVID-19; SARS-CoV-2; deep vein thrombosis; pulmonary embolism; venous thromboembolismHumanAdultmedicine.medical_specialtyAdolescentClinical Sciencesvenous thromboembolism610 Medicine & healthGlobalSurg CollaborativeVenous Thromboembolism/etiologydeep vein thrombosisNOCOVIDSurg CollaborativeYoung AdultMedicine General & InternalAge DistributionClinical ResearchCOVID‐19General & Internal MedicinemedicineHumansSex DistributionAgedScience & Technologybusiness.industrySARS-CoV-2PreventionNeurosciencesdeep vein thrombosiCOVID-19PneumoniaOdds ratioOriginal Articlesmedicine.diseaseSurgeryReconstructive and regenerative medicine Radboud Institute for Health Sciences [Radboudumc 10]Prospective StudieGood Health and Well BeingAnesthesiology and Pain MedicineHuman medicinePostoperative ComplicationCohort StudiebusinessVenous thromboembolism[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
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First demonstration of active plasmonic device in true data traffic conditions: On/off thermo-optic modulation using a hybrid silicon-plasmonic asymm…

2012

We demonstrate the first system-level evaluation of an active plasmonic device in 10Gb/s data traffic conditions. Thermo-optic ON/OFF modulation with 3μs response time and 10mW power consumption is presented using an asymmetric MZI silicon-plasmonic gate.

Data trafficMaterials scienceSiliconbusiness.industrychemistry.chemical_elementSilicon on insulatorResponse timeAmplitude-shift keyingOpticschemistryPower consumptionModulationOptoelectronicsbusinessPlasmon
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Dielectric-loaded plasmonic waveguide components: Going practical

2013

Surface plasmon propagating modes supported by metal/dielectric interfaces in various configurations can be used for radiation guiding similarly to conventional dielectric waveguides. Plasmonic waveguides offer two attractive features: subdiffraction mode confinement and the presence of conducting elements at the mode-field maximum. The first feature can be exploited to realize ultrahigh density of nanophotonics components, whereas the second feature enables the development of dynamic components controlling the plasmon propagation with ultralow signals, minimizing heat dissipation in switching elements. While the first feature is yet to be brought close to the domain of practical applicatio…

Materials scienceNanophotonicsOptical communicationPhysics::Optics02 engineering and technologyDielectric01 natural sciences010309 optics0103 physical sciencesPlasmonModulationbusiness.industrySurface plasmon021001 nanoscience & nanotechnologyCondensed Matter PhysicsAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsActive plasmonicsModulationSwitchingTelecommunicationsOptoelectronicsPhotonicsRouting (electronic design automation)0210 nano-technologybusiness
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Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study

2021

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26…

Lung DiseasesMaleInternationalitySARS-Cov-2 ; COVID-19 ; surgery ; pathways ; pre-operative isolationSettore MED/18 - CHIRURGIA GENERALEVascular damage Radboud Institute for Health Sciences [Radboudumc 16]pathwaysLung DiseaseESTUDOS PROSPECTIVOSCohort StudiesPatient IsolationsurgeryPostoperative Complications80 and overProspective StudiesProspective cohort study610 Medicine & healthAged 80 and overSARS-Cov-2; COVID-19; surgery; pathways; pre-operative isolationIncidence (epidemiology)Treatment OutcomeElective Surgical ProceduresFemaleElective Surgical ProcedureCohort studyHumanpre-operative isolationmedicine.medical_specialtyIsolation (health care)SARS-Cov-2Preoperative careNOCOVID-19; SARS-Cov-2; pathways; pre-operative isolation; surgeryAnesthesiologyPreoperative CaremedicineHumansElective surgeryLS7_4AgedElective Surgical Procedurebusiness.industrypathwayCOVID-19SurgeryReconstructive and regenerative medicine Radboud Institute for Health Sciences [Radboudumc 10]Prospective StudieAnesthesiology and Pain MedicineHuman medicinePostoperative ComplicationCohort Studiebusiness[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
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Data Transmission and Thermo-Optic Tuning Performance of Dielectric-Loaded Plasmonic Structures Hetero-Integrated on a Silicon Chip

2012

We demonstrate experimental evidence of the data capture and the low-energy thermo-optic tuning credentials of dielectric-loaded plasmonic structures integrated on a silicon chip. We show 7-nm thermo-optical tuning of a plasmonic racetrack-resonator with less than 3.3 mW required electrical power and verify error-free 10-Gb/s transmission through a 60-mu m-long dielectric-loaded plasmonic waveguide. We demonstrate experimental evidence of the data capture and the low-energy thermo-optic tuning credentials of dielectric-loaded plasmonic structures integrated on a silicon chip. We show 7-nm thermo-optical tuning of a plasmonic racetrack-resonator with less than 3.3 mW required electrical powe…

EXPRESSIONMaterials scienceSiliconGPR120PREFERENCEchemistry.chemical_elementPhysics::Optics02 engineering and technologyDielectric01 natural sciencesRATS010309 opticsALPHA-GUSTDUCIN0103 physical sciencesSensitivity (control systems)DIETARY LIPIDSElectrical and Electronic EngineeringPlasmonRECEPTORbusiness.industry021001 nanoscience & nanotechnologyACIDSAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsMICEchemistryPlasmonic waveguideTransmission (telecommunications)Silicon chipOptoelectronicsSENSITIVITY0210 nano-technologybusinessData transmission
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WDM switching employing a hybrid silicon-plasmonic A-MZI

2012

We demonstrate a system-level evaluation of an A-MZI with 60μm long DLSPP active branches exhibiting more than 14dB extinction ratio. Error-free switching operation is achieved for a 4×10Gb/s incoming WDM data stream with only 13.1mW power consumption.

Data streamAmplified spontaneous emissionMaterials scienceSiliconchemistryExtinction ratioWavelength-division multiplexingSurface plasmonPolaritonElectronic engineeringchemistry.chemical_elementPlasmon
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Low energy routing platforms for optical interconnects using active plasmonics integrated with Silicon Photonics

2013

Power consumption and bandwidth of electronics appear as the main set of technology barriers in next-generation Data Center and High-Performance Computing (HPC) environments. The limited capacity and pitch lane of electrically wired interconnects require the development of new disruptive technologies to cope with the massive amount of data moving across all hierarchical communication levels, namely rack-to-rack, backplane, chip-to-chip and even on-chip interconnections. Plasmonics comes indeed as a disruptive technology that enables seamless interoperability between light beams and electronic control signals through the underlying metallic layer, providing thereby an inherent energy-efficie…

RouterSilicon photonicsComputer scienceBandwidth (signal processing)02 engineering and technology01 natural sciencesMultiplexer010309 optics020210 optoelectronics & photonicsBackplaneWavelength-division multiplexing0103 physical sciencesBroadband0202 electrical engineering electronic engineering information engineeringElectronic engineeringElectronics
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