搜索
WhatisSWIR?Short-waveinfrared(SWIR)lightistypicallydefinedaslightinthe0.9–1.7μmwavelengthrange,butcanalsobeclassifiedfrom0.7–2.5μm.Sincesiliconsensorshaveanupperlimitofapproximately1.0μm,SWIRimagingrequiresuniqueopticalandelectroniccomponentscapableofperforminginthespecificSWIRrange.Indiumgalliumarsenide(inGaAs)sensorsaretheprimarysensorsusedinSWIRimaging,coveringthetypicalSWIRrange,butcanextendaslowas550nmtoashighas2.5μm.Althoughlinearline-scaninGaAssensorsarecommerciallyavailable,area-scaninGaAssensorsaretypicallyITARrestricted.ITAR,InternationalTreatyandArmsRegulations,isenforcedbythegovernmentoftheUnitedStatesofAmerica.ITARrestrictedproductsmustadheretostrictexportandimportregulationsforthemtobemanufacturedand/orsoldwithinandoutsideoftheUSA.Nevertheless,lensessuchasSWIRonescanbeusedforanumberofcommercialapplicationswithproperlicenses.Figure1:ElectromagneticSpectrumIllustratingSWIRWavelengthRangeWHYUSESWIR?UnlikeMid-WaveInfrared(MWIR)andLong-WaveInfrared(LWIR)light,whichisemittedfromtheobjectitself,SWIRissimilartovisiblelightinthatphotonsarereflectedorabsorbedbyanobject,providingthestrongcontrastneededforhighresolutionimaging.Ambientstarlightandbackgroundradiance(nightglow)arenaturalemittersofSWIRandprovideexcellentilluminationforoutdoor,nighttimeimaging.Itisessentialtousealensthatisdesigned,optimized,andcoatedfortheSWIRwavelengthrange.Usingalensdesignedforthevisiblespectrumwillresultinlowerresolutionimagesandhigheropticalaberrations.SinceSWIRwavelengthstransmitthroughglass,lenses,andotheropticalcomponents(opticalfilters,windows,etc.)designedforSWIRcanbemanufacturedusingthesametechniquesusedforvisiblecomponents,decreasingmanufacturingcostandenablingtheuseofprotectivewindowsandfilterswithinasystem.AlargenumberofapplicationsthataredifficultorimpossibletoperformusingvisiblelightarepossibleusingSWIR.WhenimaginginSWIR,watervapor,fog,andcertainmaterialssuchassiliconaretransparent.Additionally,colorsthatappearalmostidenticalinthevisiblemaybeeasilydifferentiatedusingSWIR.SWIRAPPLICATIONSSWIRimagingisusedinavarietyofapplicationsincludingelectronicboardinspection,solarcellinspection,produceinspection,identifyingandsorting,surveillance,anti-counterfeiting,processqualitycontrol,andmuchmore.TounderstandthebenefitsofSWIRimaging,considersomevisualexamplesofcommon,everydayproductsimagedwithvisiblelightandwithSWIR.Short-waveinfrared(SWIR)definesaspecificwavelengthrangeoverwhichopticalandelectroniccomponentsaredesignedandcoated.SWIRimagingoffersanumberofadvantagescomparedtovisiblewhenusedforinspection,sorting,surveillance,qualitycontrol,andhostofotherapplications.Itisimportanttochoosecomponentsspecificallydesigned,optimized,andcoatedfortheSWIRwavelengthrangetoensurethehighestresolutionandlowestaberrations.