简介:WeproposeanddemonstrateapseudoFabry–Pérotfilterintheterahertzfrequencyrangeof0.1–0.5THz.Itconsistsofalternativeliquidcrystallayersandmetallicslats.Separatesharpresonantpeaksareshowninthesimulatedtransmissionspectra,andtheirpositionsshifttowardhigherfrequencieswhentherefractiveindexofliquidcrystaldecreases.Themeasuredtransmissionspectraareconsistentwithcorrespondingsimulations.Viathermallytuningtherefractiveindexofthefilledliquidcrystal,theresonanttransmissionfrequenciesshiftaccordingly.Theworksuppliesanoveldesignfortunableterahertzfilters,whichwouldplayimportantrolesinterahertzimaging,sensing,highspeedcommunication,andsecurityapplications.
简介:大数据分析是检查具有各种类型的大量数据并快速生成以识别隐藏模式、未知相关性和其他有用信息的过程。在现代汽车集团的研发中心,有许多类型的机器能够以前所未有的规模生成数据。作者开发了一种名为VDMS的车辆信号采集设备。这种类型的传感器每天在大数据系统上存储超过1TB的数据。因此,分析不断增加的数据量和高速流传感器数据的能力是必不可少的。本文研究了传感器数据的分析方法,首先,建立了从信号数据相关性分析到分类模型的分析过程,并开发了针对信号优化的分析方法。另外,提出了一种将异常信号数据形成图案并检测特定图案的方法。
简介:Applicabilityofguidedmoderesonantstructurestotunableopticalfilteringandsensingisdemonstratedusingnematicliquidcrystals.Asasensor,aminimumrefractiveindexdetectivityof10-5isdemonstratedwhileasatunablefilter,tunabilityrangeoffewtensofnanometerswith2-nmbandwidthispresented.Theoptimumdesignisachievedbymaximizingtheevanescentfieldregionintheanalytewhichmaximizestheoverlapintegral.Thedevicecanbeoperatedinreflectionortransmissionmodesatnormalincidence.Itcanalsobeoperatedatasinglewavelengthbymeasuringtheangularprofileofthelightbeam.
简介:Awavelength-sweptlaserisconstructedusingafreespaceexternalcavityconfigurationcoupledwithafiberbasedringcavityatthe850nmregion.Theexternalcavityfilteremploysagalvo-mirrorscannerwithadiffractiongratingforwavelengthselection.Thefilterisconnectedtoaringcavitythroughanopticalcirculator.Theringcavitycontainsabroadbandsemiconductoropticalamplifierwithahighopticaloutput.Theperformanceofthislaserisdemonstratedwithbroadbandwidthsandnarrowlinewidths.The3dBlinewidthandthebandwidthofthissourceare0.05nm(~20GHz)and48nm,respectively.Themaximumoutputpoweris26mWat160mAcurrent.
简介:ThesensitivityofDopplerwindlidarisanimportantparameterwhichaffectstheperformanceofDopplerwindlidar.Aerosolscatteringratio,atmospherictemperature,andwindspeedobviouslyaffectthemea-surementofDopplerwindlidarwithiodinefilter.Wediscussabouttherelationshipbetweenthemea-surementsensitivityandtheaboveatmosphericparameters.Thenumericalrelationshipbetweenthemisgiventhroughthetheoreticalsimulationandcalculation.
简介:Two-dimensionalmetallicphotoniccrystalslabswithsquarelatticeareproposedtobeusedforthedesignofwaveguidebandpassfiltersoperatinginmillimetertoterahertzregion.Filtercharacteristicsarestudiedwhenrodradiiandlatticeconstantsarechanged.Basedonthefrequencyscalingtechnique,aseriesofhigherfrequencyfiltershasbeendesigned.Byusinglaserdrillingandweldingprocessingtechniques,acompactwaveguidefilterembeddedinanEIA-WR10waveguidewithcentralfrequency145.5GHzand3-dBbandwidthof5.26GHzisfabricatedandmeasured.Themeasurementdataagreewellwiththesimulationprediction.
简介:Ademultiplexingschemebasedonsemiconductoropticalamplifier(SOA)andopticalfilterforopticaltimedivisionmultiplexingdifferentialquadraturephaseshiftkeying(OTDM-DQPSK)systemisproposedandinvestigatedexperimentally.Withonlyacommonhalfbaudrateelectricalclockmodulated33%dutycyclereturn-to-zero(RZ-33)opticalclocksignalaspump,thisschemeiscost-effective,energy-efficient,andintegration-potential.Aproof-of-conceptexperimentiscarriedoutforthedemultiplexingofa2×40-GBdOTDM-DQPSKsignal.Error-freeperformanceisdemonstrated,andtheaveragepowerpenaltyforbothchannelsisabout3dB.