简介:Atemperaturesensorbasedonpolarizationnon-reciprocity(PNR)infiber-opticSagnacinterferometer(FSI)wasproposed.Theexperimentalstudywasmadeprimarilyandtheresultsagreewiththeorywell.Discussionshowsthatthiskindoftemperaturesensorcanachievehighprecisionandhavegreatapplicationpotential.
简介:Weproposeanddemonstrateanultrasensitiveintegratedphotoniccurrentsensorthatincorporatesasiliconbasedsingle-mode-multimode-single-modewaveguide(SMSW)structure.ThiskindofSMSWstructureisplacedoveradirectcurrentcarryingpowerresistor,whichproducesJoule’sheattochangethetemperatureoftheSMSWandfurtherresultsinthechangeoftheeffectiverefractiveindexbetweendifferentpropagatingmodes.Interferenceoccurswhenthemodesrecombineatthesecondsinglemodewaveguide.Finally,thecurrentvariationismeasuredbymonitoringtheshiftintheoutputspectrumofthemultimodeinterferometer.Inlowcurrent,thewavelengthshifthasalmostlineardependence:Δλ∝Ic.Thiseffectcanbeusedasacurrentsensorwithaslopeefficiencyof4.24nm/Aintherangeof0–200mA.
简介:Amethodofdetectingdry,icyandwetroadsurfaceconditionsbasedonscanningdetectionofsinglewavelengthbackwardpowerisproposedinthisletter.Thedetectorisusedtoreceivethebackwardscatteredpowerwhichchangeswiththeincidenceangle.Therelationshipbetweenbackwardpowerandincidenceangleisusedtofindouttheeffectiveanglerangeanddistinguishmethod.Experimentandsimulationshowthatitisfeasibletoclassifythesethreeconditionswithinincidenceangleof5.3degree.
简介:Thepiezoelectricfilmelectro-depositionforopticalfibersensorwithZnOcoatingisstudied.Thezincoxideplatingfilmismadeonthecoppersurfacedirectlybycathodicelectro-depositionintheZn(NO_3)_2singlesaltaqueoussolutionsystems.TheinfluencesofmainexperimentalconditionsonthepropertiesofZnOthinfilmintheelectro-depositionprocessesareanalyzedandastable,practicalandeconomictechniqueisobtained.
简介:Applicabilityofguidedmoderesonantstructurestotunableopticalfilteringandsensingisdemonstratedusingnematicliquidcrystals.Asasensor,aminimumrefractiveindexdetectivityof10-5isdemonstratedwhileasatunablefilter,tunabilityrangeoffewtensofnanometerswith2-nmbandwidthispresented.Theoptimumdesignisachievedbymaximizingtheevanescentfieldregionintheanalytewhichmaximizestheoverlapintegral.Thedevicecanbeoperatedinreflectionortransmissionmodesatnormalincidence.Itcanalsobeoperatedatasinglewavelengthbymeasuringtheangularprofileofthelightbeam.
简介:Apiece-wisetransitiondetectionalgorithmthatperformsdisplacementmeasurementsforself-mixingsensorsisdeveloped.Thealgorithmcancorrectlydetectself-mixingfringesatalowsignal-to-noiseratiointhepresenceofdisturbanceswithoutfiltering.Displacementreconstructionsbythephaseunwrappingmethodbasedonthisalgorithmareexperimentallyvalidated,withlasersubjecttothemoderatefeedbackregime.
简介:Anopticalfibersensorforultrathinlayersensingbasedonshort-rangesurfaceplasmonpolariton(SRSPP)isproposed,andthesensingcharacteristicsaretheoreticallyanalyzed.Simulationresultsindicatethatevenforadetectinglayermuchthinnerthanthevacuumwavelength,aresolutionashighas3.7×10-6RIUcanbeobtained.Moreover,anaveragethickness-detectionsensitivityof6.2dB/nmisobtained,whichenablesthesensortodetectthethicknessvariationoftheultrathinlayeruptotensofnanometers.Thesensitiveregionofthicknesscouldbeadjustedbytuningthestructureparameters.
简介:Adoublycladdingsingle-modefiberhumiditysensorisfabricatedbyagarose.Thesensorhasaninsertionlossof0.08dBandapowerchangeof17.83dB.Theresponsesofthesensortoarelativehumidity(RH)rangeform30%to100%atatemperaturerangeform25to34Carevalidated.TheexperimentsdemonstratethattheabsorbabilityofagarosegeltomoisturedecreaseswithincreasingRHinmeasuredgas.Weproposeacalibrationmethodthatuseslookuptablesandconstructacorrespondingcalibrationmatrix.Usingthesensor,weconductreal-timemonitoringofRHinfreshconcreteduringitshardeningprocess.
简介:Byusingagraded-indexmultimodefiber(GI-MMF)witharelativelyflatindexprofileandhighrefractiveindexofthefibercore,amicroextrinsicfiber-opticFabryProtinterferometric(MEFPI)strainsensorisfabricatedthroughchemicaletchingandfusionsplicing.Higherreflectanceofthemicrocavityisobtainedduetotheless-curvedinnerwallinthecenterofthefibercoreafteretchingandhigherindexcontrastbetweentheGI-MMFcoreandair.Themaximumreflectionofthesensorisenhanced12dBthanthatobtainedbyetchingoftheEr-orB-dopedfibers.Highfringecontrastof22dBisobtained.ThestrainandtemperatureresponsesoftheMEFPIsensorsareinvestigatedinthisexperiment.Goodlinearityandhighsensitivityareachieved,withwavelength-strainandwavelength-temperaturesensitivitiesof7.82pm/μεand5.01pm/°C,respectively.
简介:Weproposeahighsensitivitysensorbasedonamodenumber-encodedmulti-longitudinalmodefiberlaser.ThefiberlaserincorporatesauniformfiberBragggrating(FBG)andafiberFabry-Perotinterferometer(FFPI)assensitivecomponentsinthecavity.Thesensorcountsthenumberoflongitudinalmodes(NLM)offiberlaser,whichiscausedbythemismatchbetweenthereflectionbandofFBGandthetransmissionbandofFFPIresultingfromtheapplicationofexternalperturbationtotheFBG.AnelectricalspectrumanalyzerisadoptedtoanalyzetheNLM.Thestrainsensorisexperimentallydemonstratedtohavesensitivityofashighas0.02με/mode.
简介:Aversatileandlow-costsingle-beamself-referencedphase-sensitivesurfaceplasmonresonance(SPR)sens-ingsystemwithultra-highresolutionperformanceispresented.Thesystemexhibitsaroot-mean-squarephasefluctuationof±0.0028°overaperiodof45min,i.e.aresolutionof±5.2×10~(-9)refractiveindexunits.Theenhancedperformancehasbeenachievedthroughtheincorporationofthreedesignelements:atruesingle-beamconfigurationenablingcompleteself-referencingsothatonlythephasechangeassociatedwithSPRgetsdetected,adifferentialmeasurementschemetoeliminatespurioussignalsnotrelatedtothesensorresponse,andtheeliminationofretardationdriftsbyincorporatingtemperaturestabilizationintheliquidcrystalphasemodulator.Ourdesignshouldbringthedetectionsensitivityofnon-labelingSPRbiosensingclosertothatachievablebyconventionalfluorescence-basedtechniques.