MCVD工艺制备光纤(制造工艺)

新型光纤材料与器件团队NOVELOPTICFIBERSANDDEVICESTEAMMCVD工艺关键技术蒋作文光纤的四大制造技术VAD（轴向汽相沉积）OVD（外部汽相沉积）MCVD（改进的化学汽相沉积）PCVD（等离子体化学汽相沉积）MCVD工艺简介MCVD工艺步骤1——RecipeDevelopmentMainvariablesforeachprocessstepsarefollowing:Gasflows:bubblercarriergas,O2,He,Cl2,SF6etc.PreformtemperatureCarriagespeedSootboxpressureRampingofrelevantparametersMCVD工艺步骤2——TubepreparationTypicalMCVDproductiontubeisconstructedfromthreequartztubes,whichareweldedtogetherpriortoMCVDprocess.inlettube:lowqualityquartzsubstratetube:highqualitysyntheticsilica,formsfinalpreformexhausttube:lowqualityquartzsleevingtube:syntheticsilicaMCVD工艺步骤3——FirePolishing/EtchingPurpose:Tocleantubeouterandinnersurfacetoimprovepreformquality.Temperature:1850-2200CReactantflows:O2+fluorinesourceforetchingSF6+O2MCVD工艺步骤4——CladdingandcoredepositionCladdingdepositionPurpose:depositionofprotectionbarrierforcore.Temperature:1900-2100oCTypicalreactantflows:SiCl4,POCl3,O2,HeCoredepositionPurpose:depositionofrefractiveindexdifferenceTemperature:1900-2200oCTypicalreactantflows:SiCl4,GeCl4,O2,HeMCVD工艺反应机理SiCl4+O2=SiO2+2Cl2GeCl4+O2=GeO2+2Cl24POCl3+3O2=2P2O5+6Cl24BCl3+3O2=2B2O3+6Cl2热泳效应热泳现象是指在温度梯度不为零的气体或悬浮体中，粒子向较冷区域运动的现象。热泳速度正比于温度梯度，而与粒径无关。MCVD工艺步骤5——CollapsingPurpose:toproduceglassrodforjacketingandfiberdrawingTypically2to5forwardand1backwardstepsTemperature:2000-2400oCChlorineusedasadryingagentMCVD工艺步骤5——Preformanalysisdimensionalandopticalparameterevaluation.importantprocessandqualitycontroltoolMorepreformanalysisPreformdimensionsPreform,claddingandcorediametersfromdifferentanglesandlongitudinalpositionsRefractiveindicesSubstratetube,claddingandcorefromdifferentlongitudinalpositionsCutoff,MFD,ChromaticdispersionPreformnon-circularity(preform,cladding,core)Preformconcentricity(preform,cladding,core)MCVD工艺步骤6——RodintubesleevingPurpose:enlargepreformsizetoimproveMCVDproductivityTypicalfinalpreformsize:40to80mmTemperature:2000CVacuumsuctionbetweenrodandtubetoacceleratejoiningprocessFiberdrawingMCVD设备系统主要组成1.Lathe2.GasControlSystem3.PC/PLCControlSystem4.Gas&WaterSupply5.ExtractSystems.SGCMCVDMCVDLatheOxy-hydrogenburnerPyrometerFlamedetectorGasControlandsupplySystemSiliconTetrachloride(SiCl4)SupplyGermaniumTetrachloride(GeCl4)SupplyPhosphorylChloride(POCl3)SupplyBorontrichloride(BCl3)SupplyLatheHydrogen&OxygenSupplySulphurHexafluoride(SF6)SupplyChlorineSupplyOxygenSupplyHeliumSupplyNitrogenSupplyPneumaticsSupplyDryboxtemperaturecontrolGasStationExtractSystems1.Gasinlet2.Jetstreamcolumn3.Reductiontank4.Neutralizationtank5.Absorptioncolumn6.Freshwaterfeed7.Chemicalfeed8.Wastewaterdischarge9.PuregasoutletGasscrubber——JetstreamtankOver90%ofsilicaiscollectedtothe350ljetstreamtank.NaOHandNa2S2O3solutionsareautomaticallyaddedtothetanktokeepthepHinthetankbetween8and8.5andRedoxpotentialbetween-50and+200mV.ThewashedgasisdirectedtoNeutralizationtankthroughamisteliminator.Jetstreamtankreceivescontinuous15-40l/hoverflowfromNeutralizationtank.Gasscrubber——NeutralizationtankThewashedgasfromstage1isdirectedtothestage2throughasetofdampersandmisteliminator(chevrontype).pHofstage2tankiskeptbetween10and11toensureefficientneutralizationoftheHClgas.HCl+NaOH--NaCl+H2OCl2+2NaOH--NaCl+NaClO+H2O新型光纤材料与器件团队NOVELOPTICFIBERSANDDEVICESTEAM谢谢！