简介：WepresentaHerriott-typemultipasslaserabsorptionspectrometerenhancedbyopticalheterodynedetection.Theproposalisdemonstratedbymeasuringthespectraofwatervapormoleculeintheregionfrom12247.6873to12249.6954cm-1.Comparedwithdirectabsorptionspectroscopy,thesignal-to-noiseratioisimprovednearlyonemagnitudeoffactorbycombiningwiththeopticalheterodynespectroscopyandextraweakabsorptionlinesareobserved.Theminimumdetectableabsorptionisestimatedat4.36×10-8cm-1andthemeasuredlineshapedominatedbyDopplerbroadeningcanbepreciselyrecoveredbydirecttransformationofexperimentalopticalheterodynespectralprofile.

简介：WeanalyzetherandomdisturbanceinthetransmissionoflightthroughaspinningGlan-Thompsontypeprismpolarizer.ThedisturbancemakesthedependenceofthetransmissionontherotationanglesignificantlydeviatesfromtheMaluscosine-squaredlawandseverelyspoilstheoutputlightquality.Slightvibrationofthepolarizerasitrotatescombingthemulti-beam-interferenceeffectraisesthedisturbance.Furtheranalysisrevealsthesensitivedependenceofthedisturbanceonthecomposingmaterialoftheprismgap,andtheappropriateselectionofsuchmaterialcanmakethedisturbanceminimizetoverydesirablelevels.Themodelresultsshowquitegoodagreementwithexperiments.

简介：Anovelno-guidelightpentype3D-coordinatemeasurementsystemwiththreesetsofpositionsensitivedevices(PSDs)torealizeintersectionconvergeinagingisintroduced.Itiscalledasthelightpentypemeasurementsystem,becausethemeasuringheadisshapedasapenwithseverallightsourcesonit.Thestructuredesign,measurementprincipleandexperimentalresultsarepresented.Thetheoreticalanalysisandexperimentalresultsprovethatthissystemhasadvancedfeaturesofsimplestructure,highautomation,andhighaccuracy,andcanbeusedinthemeasurementfieldsofmechanicalmanufacture,robot,auto,aviationandmedicineeffectively.

简介：Adouble-slitghostinterferenceexperimentperformedonanentangledresourceusingtype-IInon-collineardegeneratespontaneousparametricdown-conversion(SPDC)isdemonstrated.Theinfluenceofthedistancebetweenthedouble-slitandthebucketdetectorprecededbyapinholeisstudied.Theexperimentalresultsshowthattheinterferencefringesbecomeincreasinglydistinctwithhighervisibilitywhenthepinhole-double-slitdistanceincreases.Afirst-orderclassicaltheorybasedontheKlyshko’stwo-photonadvanced-wavepicture,andasecond-orderquantum-imagetheoryareprovidedforexplanations.Thefittingresultsindicatethatthedivergenceoftheconvertedfluorescencesignificantlyaffectstheghostfringes.