激光器驅(qū)動(dòng)電路中英文翻譯

1、激光器驅(qū)動(dòng)電路中英文翻譯激光器驅(qū)動(dòng)電路中英文翻譯激光器驅(qū)動(dòng)電路中英文翻譯中文2540字LaserdrivercircuitSmallchangeswilldirectlysemiconductorlaserdrivecurrenttotheoutputintensityfluctuation.Tostabilizetheoutputpowersemiconductorlaser,Voltagenegativefeedbackprincipletodesignaconstantcurrentdrivingcircuitcomprisesasoftstartingandcurrentlimitin

2、gprotectioncircuitbasedon;Atthesametime,accordingtotheneedofthelightsourceismodulatedtoeliminatetheinfluenceofbackgroundlightand,integratedlasermodulationcircuitcomprisesacrystaloscillationcircuitanddividercircuitdesign.Makingthespecificcircuitandcompletetherelevantexperimental.Theexperimentalresult

3、sshowthatthecircuitcanprovideadrivingcurrentofhighstability,Currentstabilityupto0.05%;Softstartandcurrent-limitingprotectioncircuitcanprotectthesemiconductorlaserandenhancetheimpactcapability.Modulationcircuitgeneratesacarriersignalneededforlaserdiodemodulationanddirecttocompletetheoutputlightmodula

4、tion,Theswitchcanbeconvenientlyrealizedfrom256Hzto512kHzrangeof12kindsofcommonlyusedmodulationfrequencyselection.Semiconductorlaserwithitsexcellentcharacteristics,highefficiency,simplestructure,smalliswidelyusedinscientificresearch,nationaldefense,medical,andotherareasofprocessing,itsdrivetechnology

5、becomesmoreandmoreimportant.Semiconductorlaseristheidealelectron-photondirectconversiondevices,quantumefficiencyisveryhigh,thecurrentsmallchangeswillleadtoagreatchange,theoutputlightintensityofthetherefore,semiconductorlaserdrivecurrentrequirementsisveryhigh.Drivingtechnologyofsemiconductorlaserusua

6、llyadoptsconstantcurrentdrivemode,thiswork,throughtheprincipleofnegativefeedbackcontrolloop,directlyprovidetheeffectivecontrolofthedrivecurrent.Inaddition,thetransientcurrentorvoltagespikes,andovercurrent,overvoltagewilldamagethesemiconductorlaserdrivecircuit,thereforeshouldbeconsideredintheprotecti

7、oncircuitagainstelectricshockmeasuresandspecial.Insomeapplications,DCsemiconductorlasersproduceDCdrivelightinthemeasurementprocessisvulnerabletointerferencefromambientlightslowchange,whichcouldnotbeseparatedfromtheenvironmentlightrequiredDCopticalsignal,thesignal-to-noiseratioistoosmall,sotocarryont

8、hemodulation.Whenthehigh-speedmodulatedsemiconductorlasers,therewillbedynamiccharacteristicsis1complex,suchastherelaxationoscillation,sincethepulseandmulti-pulsephenomena.Inthispaper,experimentswereconductedtostudythecharacteristicsoflowfrequencymodulation.Semiconductorlaseroutputisstable,andcanbedi

9、rectlymodulated,ithasbeenwidelyappliedinopticalsystem,isthepreferredsourcesensorsystem.Thispaperdescribesthedesignofahighstabilitydrivingcurrent,modulation,simpleoperationandlowcostdrivingcircuitforthelightsourceofopticalfibersystems.Inthispaper,thedesignofdrivingthesemiconductorlasermodulationcircu

10、itcomposedoffourparts,includingconstantcurrentcircuit,asoftstart,currentlimitprotectionandmodulationsignalgeneratingcircuit.Theconstantcurrentcircuittogenerateahighstabledrivecurrent.Softstartistheroleofeliminatingsurgemaybepresentinthecircuit,topreventtheharmofsurgeforlaser.Toavoiddamageduetoovercu

11、rrentcausedbysemiconductorlasercannotberestored,thenaddingcurrent-limitingprotectioninadrivercircuit.Circuittorealizethemodulationandfrequencycanbeadjustedtogenerateamodulatedsignal.Theconstantcurrentcircuitisshowninfigure1,Thein-phaseendvoltagereferenceVrintoA1opamp,theoperationalcontrolamplifierco

12、nductinglevel,andthustoobtainthecorrespondingoutputcurrent.TheoutputcurrentgeneratedbysamplingvoltagesamplingresistorRs,thesamplingvoltageisamplifiedastheinvertinginputvoltagefeedbackvoltagefeedbackamplifierA1,andvoltageandthein-phaseinputendofcomparison,Q2toadjusttheoutputvoltagethroughthetriode,ad

13、justmentandoutputcurrentofsemiconductorlasers,sothatthewholeclosed-loopfeedbacksysteminthedynamicbalance.+12VR7A11KQ2Vr2N2222AOPAMPU71-12V2laserAR?61OPAMPR81A1R5A161R6A161M5.1KFigure1ConstantcurrentmapBecausetheswitchinstantaneousinpowersupplygeneratesavoltage,currentsurge,aswellasthesurgeinterferen

14、ceeffectsarelikelytocausethebreakdownand2thedamageofthesemiconductorlaser,andthereforemustbeinthedesignofsoftstartcircuitdrivelaser,namelytheuseofthechargeanddischargeofRCcircuit,delaytime,thespecificcircuitasshowninFigure2asshownin.SwitchS1isclosed,thecurrentthroughtheresistorR1andcapacitorC3tochar

15、ge,thebaseelectrodeofthetriodeQvoltagegraduallyrises.Asthecapacitorchargingandtheconductionofthetriode,outputvoltageVoisachievedfrom0tothemaximumriseslowly,untilthecapacitorchargesaturation,thevoltageandcurrentstabilizing.Whenthepowersupplyisdisconnected,theprocessofreverse,soastorealizethecurrentan

16、dvoltagedecreasesslowly.S1U1R1Q78L052N2222A1Vout31MVinDNGC3C6C21051052104V0Figure2SoftstartcircuitdiagramLasersoftstarttimeandthechargingcapacitorandthecorrespondingresistance,whenthecapacitorchargingtendstosaturation,theoutputvoltagesoftstartcircuitcanachievemaximum.PowersupplyvoltageisVI,thecapaci

17、torvoltageisVo,thecapacitorchargingformula:1V0Vi(1eRC)Accordingtothisformulacancalculatetheelectricchargeanddischargetime.Semiconductorlaserwithotherdevices,havenormalworkingcurrent,ifthecurrentexceedsthisrange,thelaserwillbedamaged,thereforemustrestrictcurrentlaserinthesetrange.Emittervoltagetransi

18、storQ2asthefeedbackvoltageterminalphaseinA3opamp,whenthefeedbackvoltageislessthanthelimitvoltage,VA3opampoutputlowlevel,thetransistorQ1isturnedon,thistimebyatriodeQ2outputvoltagefeedbackvoltageisgreaterthanthelimit;whenthevoltageofV,A3opampoutputhigh,triodeQ1cutoff,thislimitsthetriodeQ2emissionincre

19、asesverycurrent,andislimitedtoaspecificvalue.SoevenifthecurrentcausedbyVrcontrolvoltageexceedstheset3value,thetriodeQ1andQ2areconnectedinseries,sothetotalcurrentwillbeclampedinthesettingcurrentvalue.Modulationsignalgeneratingcircuitiscomposedofacrystaloscillatingcircuitanddividercircuitiscomposedoft

20、woparts,usedtogeneratethehighstabilityoffrequency,dutycyclesquarewavesignalisstable.Crystaloscillatingcircuitdirectlygeneratedbytheactiveoscillator,oscillationfrequencyis1MHz.FrequencydividercircuitcomposedofaCMOSintegratedcircuit4040.1MHzpulsesignalafterthefrequencyby4040,pinoutputfrequencyfromthes

21、witchisselected,thedutycycleis50%,amplitudeis5Vsquarewavesignal.Themodulationfrequencydividingfrequencywere256Hz,512Hz,1kHz,2kHz,4kHz,8kHz,16kHz,32kHz,64kHz128kHz,256kHz,512kHz.Drivinganimportanttechnicalparametersofcircuitforcurrentstability.Currentstabilityisinacertainperiodoftime,severalmeasureme

22、ntsthroughthecurrentsizeofthesemiconductorlaser,namelytheratioofoutputcurrentstabilityfortherelativechangeamountandinputcurrent,stabilitycalculation,therewillbecurrentrelativechangeisdefinedasthemeasurementofthemaximumandminimumvalues,willmeasuretheaveragevalueastheinputcurrentvalue.Drivecircuitbase

23、donvoltagenegativefeedbackprinciple,byconstantcurrentdrivemodetorealizethecontroloftheinjectioncurrentandoutputpowerofsemiconductorlaser,anditcanprovidehighstableoutputcurrent,currentstability0.05%.Drivecircuitwithsoftstart,currentlimitcircuitprotection,reducethedamageofsemiconductorlasertosurgebrea

24、kdownandcurrent,themodulationcircuitandthedrivecircuiteffectivelycombined,realizethefrequencyis,thedevelopmentofnewtechnologyofopticalfibercommunicationisessential.Thecausesofdispersion:Oneisthelightemittedbythelightsourceisnotmonochromaticlight;twoisthemodulationsignalhasacertainbandwidth.Thedisper

25、sionoftheclassification:Bydifferentmodesordifferentfrequency(orwavelength)lightsignalcomponents,transmissioninopticalfibers,duetothephysicalphenomenonofdifferentgroupvelocitiescausesignaldistortioniscalledfiberdispersion.Thefiberdispersionisdividedintomodedispersion(orintermodaldistortion),materiald

26、ispersionandwaveguidedispersion.Aftertwokindsofdispersionisthedispersionapattern,alsoknownasintra-modaldispersion.Dispersionharm:Fiberdispersioninopticalsignalwaveformdistortion,performanceforthepulsewidth,itisthetimedomaincharacteristicsofopticalfiber.4Indigitalcommunicationsystem,pulsebroadeningof

27、opticalsignalisanimportantindex.Pulsebroadeningistoolargecancauseadjacentpulsegapdecreases,theadjacentpulsewilloverlapandregenerativerepeaterdecisionerrorsoccur,whichincreasestheBER,transmissionbandwidthnarrowing,limitthetransmissioncapacityofopticalfiber.Saidmethodofdispersion:Commonlyuseddispersio

28、nrepresentationhasmaximumtimedelayfor$S,pulsewidthRandopticalbandwidthof3dBBthree.Themaximumtimedelaydifferencedelaydescriptionfiberinthefastestandmostslowwavecomponent.Usedtodescribetheeffectoffiberdispersiononthetransmissionsignalpulsebroadeningandopticalfiberbandwidth.Asectionofopticalfiberasanet

29、workanalysisofthedispersioncharacteristics,theavailabletimedomainmethodandfrequencydomainmethod.Wheninthetimedomainanalysis,dispersioneffectisrepresentedbythepulsebroadening,andanalyzedinthefrequencydomain,thetransmissionbandwidthsaid.5激光器驅(qū)動(dòng)電路半導(dǎo)體激光器驅(qū)動(dòng)電流的微小變化將直接致使其輸出光強(qiáng)的顛簸。為實(shí)現(xiàn)半導(dǎo)體激光器的堅(jiān)固功率輸出,鑒于電壓負(fù)反應(yīng)原理設(shè)計(jì)

30、了包含軟啟動(dòng)和限流保護(hù)電路的恒流驅(qū)動(dòng)電路;同時(shí)針對(duì)為除去背景光的影響而對(duì)光源進(jìn)行調(diào)制的需要,設(shè)計(jì)了包含晶體振蕩電路和分頻電路的集成激光器調(diào)制電路。制作詳細(xì)電路并完成了有關(guān)實(shí)驗(yàn)。實(shí)驗(yàn)結(jié)果表示該電路能夠供給高堅(jiān)固度的驅(qū)動(dòng)電流,電流堅(jiān)固度達(dá)0.05%;軟啟動(dòng)和限流保護(hù)電路可保護(hù)半導(dǎo)體激光器并提升其抗沖擊能力。調(diào)制電路產(chǎn)生半導(dǎo)體激光器調(diào)制所需的載波信號(hào)并直接達(dá)成輸出光調(diào)制,經(jīng)過(guò)開(kāi)關(guān)可方便地實(shí)現(xiàn)從256Hz到512kHz范圍內(nèi)12種常用調(diào)制頻次的選擇。半導(dǎo)體激光器以其超小型、高效率、構(gòu)造簡(jiǎn)單等優(yōu)秀特色被廣泛應(yīng)用于科研、國(guó)防、醫(yī)療、加工等領(lǐng)域,其相應(yīng)的驅(qū)動(dòng)技術(shù)也顯得愈來(lái)愈重要。半導(dǎo)體激光器是理想的電子-光

31、子直接變換器件,有很高的量子效率,微小的電流變化都將致使其輸出光強(qiáng)的很大變化,所以,半導(dǎo)體激光器的驅(qū)動(dòng)電流要求特別高。半導(dǎo)體激光器的驅(qū)動(dòng)技術(shù)平常采納恒流驅(qū)動(dòng)方式,在此工作方式下,經(jīng)過(guò)負(fù)反應(yīng)原理控制回路,直接供給驅(qū)動(dòng)電流的有效控制。其余,瞬態(tài)的電流或電壓尖峰脈沖,以及過(guò)流、過(guò)壓都會(huì)破壞半導(dǎo)體激光器,所以驅(qū)動(dòng)電路中還應(yīng)試慮特其余抗電沖擊舉措和保護(hù)電路。在一些丈量應(yīng)用中,直流驅(qū)動(dòng)的半導(dǎo)體激光器產(chǎn)生的直流光在丈量過(guò)程中簡(jiǎn)單遇到遲緩變化的環(huán)境光的攪亂,致使沒(méi)法從環(huán)境光中分別出所需直流光信號(hào),本文系統(tǒng)信噪比過(guò)小,所以要對(duì)其進(jìn)行調(diào)制。當(dāng)半導(dǎo)體激光器進(jìn)行高速調(diào)制時(shí),會(huì)出現(xiàn)很復(fù)雜的動(dòng)向特色,如馳豫振蕩、自脈動(dòng)以

32、及多脈沖等現(xiàn)象。本文對(duì)其低頻調(diào)制特色進(jìn)行了實(shí)驗(yàn)研究。半導(dǎo)體激光器輸出有足夠的堅(jiān)固性,且可直接調(diào)制,它已在光纖系統(tǒng)中獲取廣泛應(yīng)用,是傳感器系統(tǒng)的首選光源。本文為光纖系統(tǒng)的光源設(shè)計(jì)了一種高堅(jiān)固度驅(qū)動(dòng)電流、可調(diào)制、操作簡(jiǎn)單且成本低價(jià)的驅(qū)動(dòng)電路。本文設(shè)計(jì)的半導(dǎo)體激光器驅(qū)動(dòng)調(diào)制電路由四大多數(shù)構(gòu)成,包含恒流電路、軟啟動(dòng)、限流保護(hù)和調(diào)制信號(hào)產(chǎn)生電路。恒流電路產(chǎn)生高堅(jiān)固度驅(qū)動(dòng)電流。軟啟動(dòng)的作用是除去電路中可能存在的浪涌,防備浪涌對(duì)激光器的危害。為防備因?yàn)檫^(guò)流等要素惹起半導(dǎo)體激光器不能夠恢復(fù)的破壞,則在驅(qū)動(dòng)電路中加入限流保護(hù)。調(diào)制信號(hào)產(chǎn)生電路實(shí)現(xiàn)調(diào)制和頻次可調(diào)。實(shí)質(zhì)的恒流電路見(jiàn)圖1,基準(zhǔn)電壓Vr送入運(yùn)放A1的同

33、相端,該運(yùn)放控制放大器的導(dǎo)通程度,并由此獲取相應(yīng)的輸出電流。該輸出電流經(jīng)過(guò)取樣電阻Rs產(chǎn)生取樣6電壓,該取樣電壓經(jīng)放大后作為反應(yīng)電壓反應(yīng)回電壓放大器A1的反相輸入端,并與同相輸入端的電壓比較,經(jīng)過(guò)三極管Q2對(duì)輸出電壓進(jìn)行調(diào)整,從而對(duì)半導(dǎo)體激光器的輸出電流進(jìn)行調(diào)整,使整個(gè)閉環(huán)反應(yīng)系統(tǒng)處于動(dòng)向的均衡中。+12VR7A11KQ2Vr2N2222AOPAMPU71-12V2laserAR?61OPAMPR81AR5AR6A1161161M5.1K圖1恒定電流圖因?yàn)樵陔娫撮_(kāi)關(guān)開(kāi)啟的瞬時(shí)會(huì)產(chǎn)生電壓、電漂泊涌沖擊,以及外界攪亂產(chǎn)生的浪涌影響都有可能造成半導(dǎo)體激光器的擊穿和破壞,所以必然在激光器驅(qū)動(dòng)電路中設(shè)計(jì)

34、軟啟動(dòng)電路,即利用RC電路的充放電,實(shí)現(xiàn)時(shí)間上的延緩,詳細(xì)電路如圖2所示。開(kāi)關(guān)S1閉合后,電流經(jīng)電阻R1向電容C3充電,三極管Q基極電壓漸漸高升。跟著電容的充電以及三極管的導(dǎo)通,輸出電壓Vo實(shí)現(xiàn)了從0到最大的遲緩上漲,直到電容充電飽和后,此時(shí)電壓和電流趨于堅(jiān)固。當(dāng)電源斷開(kāi)時(shí),上述過(guò)程反向,從而實(shí)現(xiàn)電流和電壓的遲緩降落。S1U1R1Q78L052N2222A1Vout31MVinDNGC3C62C2105105104V0圖2軟啟動(dòng)電路圖激光器的軟啟動(dòng)時(shí)間與充電電容和相應(yīng)電阻有關(guān),當(dāng)電容充電趨于飽和時(shí),軟啟動(dòng)電路的輸出電壓能夠達(dá)到最大。設(shè)電源電壓為Vi,電容電壓為Vo,電容充電公式為:71V0Vi(1eRC)依據(jù)此公式能夠計(jì)算電路充放電的時(shí)間。半導(dǎo)體激光器同其余器件同樣,都有正常工作電流,假如電流超出這個(gè)范圍,激光器將會(huì)被破壞,所以必然把激光器的工作電流限制在設(shè)定范圍內(nèi)。三極管Q2的發(fā)射極電壓作為反應(yīng)電壓加在運(yùn)放A3的同相端,