简介：Anovellenssystemwithcorrectionofsecondaryspectrumwithoutusinganomalousglassesispresented.Thelenssystemcomprisesfourseparatedlenscomponents,withthreeofthembeingsubapertures.Twoexamplesofapochromatictelescopearepresented,bothwiththeuseoftypicalnormalglasses,namelycrownK9andflintF5glasses,andlow-costslightlyanomalousdispersionglasses.Secondaryspectrumandotherchromaticaberrationsofthetwodesignexamplesarecorrected.

简介：Anewtypeoffiberopticglucosebiosensorbasedonfluorescencequenchinghasbeendesignedanditspropertieshavebeenstudied.Glucosecanbeoxidizedbyoxygenwhenglucoseoxidaseareusedasthecatalyst,therefore,theconcentrationofglucosecanbemeasuredbydetectingtheconsumptionofoxygen.Forthedetectionofoxygenconcentration,theruthenium(Ⅱ)complex,Ru(bpy)3Cl2,wereusedasthefluorescenceindicatoranditsfluorescencelifetimeweredetectedbylock-intechnology.Thedetectingrangeofthesensoris50-500mg/dlanditsresponsetimeis30seconds,showingthatthiskindofsensorsispossibletobeusedinclinicaldiagnosisanddetection.

简介：Asimpledesignprocedureisusedtogeneratephotoniccrystalfibers(PCFs)withultra-flattenedchromaticdispersion.Onlyfourparametersarerequired,whichnotonlyconsiderablysavesthecomputingtime,butalsodistinctlyreducestheair-holequantity.Theinfluenceoftheair-holediametersofeachringofhexagonalPCFs(H-PCF,including1-hole-missingand7-hole-missingH-PCFs),circularPCFs(C-PCF),squarePCFs(S-PCF),andoctagonalPCFs(O-PCF)isinvestigatedthroughsimulations.ResultsshowthatregardlessofthecrosssectionstructuresofthePCFs,the1stringair-holediameterhasthegreatestinfluenceonthedispersioncurvefollowedbythatofthe2ndring.The3rdringdiameteronlyaffectsthedispersioncurvewithinlongerwavelengths,whereasthe4thand5thringshavealmostnoinfluenceonthedispersioncurve.Thehole-to-holepitchbetweenringschangesthedispersioncurveasawhole.Basedonthesimulationresults,aprocedureisproposedtodesignPCFswithultra-flatteneddispersion.Throughtheadjustmentofair-holediametersoftheinnerthreeringsandhole-to-holepitch,aflatteneddispersionof0±0.5ps/(nm·km)withinawavelengthrangeof1.239–2.083μmfor5-ring1-hole-missingH-PCF,1.248–1.992μmfor5-ringC-PCF,1.237–2.21μmfor5-ringS-PCF,1.149–1.926μmfor5-ringO-PCF,and1.294–1.663μmfor7-hole-missingH-PCFisachieved.

简介：

简介：Diffractiveopticsisanimportanttechniqueforbeamshapingwithhighlightefficiencyandstrongdiffractionpatternflexibility.Sincethediffractionangleislimitedbytheunitsizeofthediffractiveopticalelement(DOE),thesizeoftherequireddiffractionpatternisalwaysrathersmall.InthisLetter,refractive/diffractivehybridopticalelements(RDHOEs)consistingofaDOEandalensareusedtorealizebeamshapingforalargediffractionpattern.Thelens,asthecomponentoftheRDHOEs,cannotonlybeconcavebutalsoconvex,andthedoublesamplingFresneldiffractionalgorithmisdevelopedforthedesignofthesetwotypesofRDHOEs.Thesimulationandexperimentalresultsprovidesolidevidencetodemonstratetheproposedmethodwiththepurephasespatiallightmodulator.

简介：Thenumericalstudyontheperformanceoflarge-mode-area(LMA)fiberscoiledontoaspoolinhighpoweramplifieriscarriedoutasthebend-induceddistortionoffibermodesseverelyaffectstheoutputcharacteristicsofamplifiersystems.Thevariationsforhigh-ordermodebenddistortionwithdifferentorientationsrelativetotheplaneofthefiberbendareobservedandshown.Concerningthepracticalapplications,abend-resistantLMAfiberwiththemodearealargerthan1000μm2andexcellenthighordermodesuppressionisdesignedcompletelybyoptimizingtherefractiveindex(RI)anddopantprofile.TheresultsindicatethatahybridprofileofRIanddopantisthebestchoiceforLMAfiberwithcoiling.

简介：Anoptimizeddesignoflaserrangefindingsystemusingtheself-mixingeffectinasingle-modevertical-cavitysurface-emittinglaser(VCSEL)isproposed.Inordertoimprovetherangingaccuracyandexpanddynamicmeasurementrange,weapplydifferencefrequencyanalogphase-lockedloop(PLL)insteadoffastFouriertransform(FFT)toprocesssignal,andchoosetheoptimumtriangularwavefrequencyfm=500Hzandsmallmodulationcurrent△Ip-p=0.28mAtomodulatesingle-modeVCSEL.Theexperimentresultsshowthat,withoutcontrollingthelaser'stemperature,therangingaccuracyisbetterthan2mmandthemeasurementdynamicrangeisaslargeas50-500mmwhenthesamplingtimeis0,1sandtheroomtemperatureis0-55℃.

简介：Anultra-broadbandandfabrication-tolerantsiliconpolarizationrotatorsplitterisproposedinthisLetter.Benefittingfromthebroadbandandlow-losscharacteristicsofthebi-leveltaperandcounter-taperedcoupler,thedesigneddevicehasasimulatedinsertionlossandcrosstalkoflessthan0.2and-15dBinthewavebandfrom1290to1610nm.Thesecharacteristicsmakeitvaluableinapplicationswithlargebandwidthrequirements,suchasfull-gridCoarsewavelengthdivisionmultiplexer(CWDM)anddiplexer/triplexerfiber-to-the-homesystems.Thefabricationtoleranceofthedesignisalsoanalyzed,showingthatthedeviceperformanceisquitestablewithnormalmanufacturingerrorsinsiliconphotonicsfoundries.