1. Keeb kwm
Fiber Laser yog ib lub laser uas siv lub ntiaj teb tsis tshua muaj lub ntiaj teb doped iav fiber ntau li qhov nruab nrab qhov nce, uas muaj thaj tsam ntawm qhov chaw / ntim qhov sib piv ntawm ntau tshaj 1000 npaug ntawm cov tsoos khoom thaiv laser, nrog rau kev ua kom sov zoo. Rau ib puas watts ntawm fiber ntau laser, ntuj tshav kub dissipation tuaj yeem ua tau raws li qhov xav tau ntawm cov cua sov dissipation. Txawm li cas los xij, nrog kev txhim kho sai ntawm fiber ntau lasers, lawv cov zis hluav taws xob nce xyoo los ntawm lub xyoo, txawm tias ncav cuag kilowatt nplai, vim muaj ntau yam, xws li quantum poob, fiber ntau yuav ua rau muaj kev cuam tshuam loj heev. Thermal diffusion ntawm cov khoom siv matrix ua rau muaj kev ntxhov siab thiab kev hloov pauv hloov pauv, qhov qis qis ntawm cov txheej txheem polymerization yog qhov ua rau thermal puas, uas tuaj yeem ua rau thermal fiber ntau tawg; Nrog rau qhov nruam tsub zuj zuj ntawm cov cua sov, lub doped core kub yuav nce, tus naj npawb ntawm hais nyob rau hauv lub laser subenergy theem nce ua rau kom muaj zog pib zog thiab nqes hav efficiency ntawm lub laser txo, thaum lub txo nyob rau hauv lub quantum efficiency yuav ua rau cov zis wavelength hloov. . Txhawm rau txhawm rau txhim kho lub zog hluav taws xob laser txuas ntxiv, fiber ntau laser yuav tiv taus lub zog siab dua lub twj tso kua mis lub teeb txhaj tshuaj thiab lub zog ntom ntom ntawm cov teeb liab teeb pom kev zoo, txhawm rau daws nws cov teebmeem thermal yog qhov kev sib tw loj heev uas ntsib lub zog fiber ntau laser system.
2. Qhov chaw ntawm thermal teebmeem hauv fiber ntau laser
2.1 Quantum poob nyhuv
Quantum poob cov nyhuv yog qhov tseem ceeb ntawm cov cua sov hauv thaj chaw fiber ntau tseem yog lub hauv paus ntawm cov cua sov. Vim qhov sib txawv ntawm qhov sib txawv ntawm lub twj tso kua mis wavelength thiab lub teeb liab wavelength, tag nrho cov fiber ntau laser tshuab tau nrog ib feem ntawm quantum poob. Noj 1080 nm laser output wavelength ua piv txwv, qhov kev faib ua feem ntawm quantum poob ntawm 915 nm twj wavelength yog li 15.3 feem pua.
2.2 Ntau qhov poob
Fiber coatings saum toj no qhov tseem ceeb kub ntawm 80 degree yuav tsim cov khoom denaturation los yog nto chaffing thiab lwm yam tshwm sim. Nyob rau hauv high-power nruam fiber ntau laser ua hauj lwm, fiber coatings muaj feem ntau yuav ua tau ntau tshaj qhov txwv ntawm thermal loads uas yuav zam tau, ua rau cladding lub teeb to, thiab thaum kawg yuav ua rau tag nrho cov burnout ntawm laser.
Lub ntsiab lus fusion ntawm fiber ntau muaj qhov cuam tshuam loj dua thermal, feem ntau yog los ntawm ob yam: 1) cov khoom siv fiber ntau thiab cov khoom siv rov qab nqus ntawm lub teeb hloov dua siab tshiab yuav ua kom sov, nyob rau hauv qhov ntev ntev, yuav luag tag nrho cov pob tshab recoating txheej ntawm kev nqus ntawm lub teeb. tsawg heev, tab sis nws nto yuav tsim ib co micro-voids, huab cua yog ib tug tsis zoo conductor ntawm tshav kub, lub xub ntiag ntawm voids ua rau lub thermal kuj yuav loj, yog li nws yog ib qho yooj yim los tsim thermal deposition ntawm lub fusion point Yog li ntawd, fusion point. nws yooj yim rau thermal deposition, ua rau muaj qhov kub thiab txias; 2) fusion tsis haum lossis ob ntu ntawm cov khoom siv kho qhov muag fiber ntau tsis sib xws, uas yuav ua rau fusion poob, muaj thermal kuj ua rau qhov kub thiab txias ntawm fusion point. Qhov nce ntawm qhov kub thiab txias ua rau thermal puas rau cov fiber ntau optical, thiab tib lub sijhawm muaj kev cuam tshuam ntau dua rau cov lej aperture ntawm optical fiber ntau, thiab qhov kev hloov pauv ntawm cov lej aperture cuam tshuam rau kev taw qhia lub teeb.
2.3 Cov nyhuv hluav taws xob tshwm sim
Hauv cov qauv MOPA, thaum lub teeb liab tsis muaj zog, qhov ntau ntawm cov twj tso kua mis txhaj tshuaj tuaj yeem ua rau muaj qhov tshwm sim ntawm fiber ntau spontaneous radiation (ASE). Ib tug loj npaum li cas ntawm random spontaneous hluav taws xob teeb xau los ntawm cov tub ntxhais mus rau hauv lub iav cladding raws li zoo raws li lub fiber txheej thiab overheats thiab hlawv cov organic txheej. Tsis tas li ntawd, tiam ntawm ASE kuj ua rau kom quantum poob, ua rau kom muaj cua sov nyob rau hauv cov tub ntxhais cheeb tsam ntawm fiber ntau.
2.4 Stimulated Raman scattering nyhuv
Nrog rau qhov tshwm sim ntawm ultra-high-power fiber lasers, lub zog laser lub zog nyob rau hauv cov tub ntxhais cheeb tsam maj mam nce, thiab cov nyhuv Raman tawg (SRS) maj mam dhau los ua qhov tseem ceeb txwv rau kev txhim kho lub zog. Thaum lub sijhawm ua haujlwm siab, thaum lub teeb liab laser optical fais fab mus txog qhov chaw pib ntawm SRS, lub teeb liab laser excites thiab twj Raman teeb nrog qis zaus, ua rau Raman lub teeb amplification txheej txheem. Nyob rau tib lub sijhawm, nrog rau quantum poob, SRS yuav ua rau muaj teeb meem cua sov hauv thaj tsam tseem ceeb ntawm cov fiber ntau.
3. Cov nyhuv thermal
Cov nyhuv thermal ntawm fiber ntau laser muaj qhov cuam tshuam tsis zoo ntawm cov fiber ntau thiab cov khoom tso tawm, yog li nws tseem ceeb heev kom txo tau qhov tsis zoo ntawm thermal nyhuv. Kev tawm tsam ntawm cov nyhuv thermal feem ntau tsom rau peb yam hauv qab no:
1) Tsim nyog xaiv ntawm fiber ntau tsis raws li qhov kub thiab txias txoj kev xav qauv ntawm fiber ntau;
2) Kev xaiv tsim nyog ntawm cov qauv siv thiab cov twj tso kua mis yog qhov tsim nyog rau kev ua kom pom qhov sib txawv ntawm qhov kub thiab txias thiab txo cov nyhuv thermal;
3) Kev xaiv cov txheej txheem sab nraud ntawm cov cua sov tuaj yeem txo qhov tsis zoo ntawm cov teebmeem thermal.
3.1 Optimization ntawm fiber ntau tsis
Lub ntsiab tseem ceeb cuam tshuam rau qhov kub thiab txias ntawm cov khoom siv fiber ntau yog cov thermal conductivity ntawm cov tub ntxhais thiab sab hauv thiab sab nrauv cladding, radial loj, qhov nqus coefficient, thiab qhov ntev ntawm cov fiber ntau optical. Kev xaiv tsim nyog ntawm cov khoom siv fiber ntau tuaj yeem tswj tau cov cua sov ntawm cov fiber ntau kom ntseeg tau tias kev ua haujlwm zoo thiab ruaj khov ntawm fiber ntau.
Cov tub ntxhais loj loj tuaj yeem txo qhov kub ntawm cov tub ntxhais, tab sis loj heev yuav cuam tshuam rau cov nqaj zoo. Txheej txheej raws li qhov nruab nrab nruab nrab ntawm fiber ntau thermal conduction, nws cov thickness muaj kev cuam tshuam zoo rau kev ua haujlwm kub ntawm fiber ntau. Raws li kev xav, qhov sib txawv ntawm qhov kub thiab txias ntawm cov txheej txheej sab hauv thiab sab nrauv ntawm txheej txheej thiab cov tuab yog qhov zoo sib xws, qhov thinner txheej txheej, qhov me dua qhov kev tiv thaiv tshav kub, qhov me me qhov kub qhov sib txawv ntawm sab hauv thiab sab nrauv ntawm tag nrho. txheej txheej, lub zog siab dua qhov system tuaj yeem tiv taus. Txawm li cas los xij, vim muaj kev cuam tshuam ntawm cov cua sov hloov mus rau ntawm qhov chaw ntawm cov khoom siv fiber ntau, thiab txheej txheej txheej muaj lub luag haujlwm ntawm kev tiv thaiv cov fiber ntau, thiab yog li ntawd yuav tsum xaiv qhov tuab ntawm txheej txheej.
Thaum cov fiber ntau txias hauv huab cua, kev sib raug zoo ntawm thermal conduction kuj Rcond, thermal convection kuj Rconv thiab tag nrho cov thermal resistance Rtot thiab txheej txheej thickness yog qhia hauv daim duab 2(a). Cov txheej txheej thickness yog zoo correlated nrog Rcond thiab tsis zoo correlated nrog Rconv, yog li nws yog tsim nyog los xaiv lub txheej txheej thickness kom ntseeg tau tias ib tug tsawg thermal kuj. Kev sib raug zoo ntawm fiber ntau ntev thiab nqus coefficient thiab kub yog qhia hauv daim duab 2(b), los ntawm kev txo qhov nqus coefficient ntawm fiber ntau, qhov nqus ntawm lub zog nqus dej tuaj yeem txo tau zoo, qhov txo qhov nqus ntawm lub zog nqus tau txhais tau tias txo cov thermal. deposition, uas txo qhov kub ntawm cov fiber ntau, tab sis nyob rau hauv thiaj li yuav ua tau zoo tib yam tso zis yuav tsum tau mus nce qhov ntev ntawm fiber, Wang li al. kawm tag nrho cov twj tso kua mis ntawm 1000 W, dual-kawg lub zog ntawm 500 W, kev siv 0.25 dpi yog siv los ua kom tiav cov zis tib yam. Wang et al. pom tias tag nrho cov twj tso kua mis yog 1000 W thiab dual-kawg twj tso kua mis yog 500 W. Lub zog tso zis yog 630 W nrog 60 m ntev fiber ntau nrog 0.25 dB nqus coefficient, thiab 725 W nrog 1.0 dB 20 m ntev fiber ntau, tab sis qhov siab tshaj plaws ntawm cov fibers tom kawg yog siab dua li ntawm cov qub fiber ntau los ntawm 200 degree. Qhov kub siab tshaj plaws ntawm cov fibers tom kawg yog siab tshaj qhov qub fiber ntau. Raws li qhov kawg ntawm cov twj tso kua mis lub zog yog qhov muaj zog tshaj plaws, txawm hais tias txo qhov nqus coefficient ntawm fiber ntau tuaj yeem txo qhov nqus ntawm lub zog nqus, tab sis raws li qhov kev xav tau ntawm kev ua haujlwm ntawm kev nqus nqus nqus, lub laser yog tias qis dua. -doped, low-absorption fibers, yuav tsum tau nce qhov ntev ntawm fiber ntau, uas nyob rau hauv lem ua rau tshwm sim ntawm lwm yam teeb meem xws li cov nyhuv nonlinear raws li ib tug poob ntawm cov zis efficiency, thiab hais txog.
3.2 Kev xaiv txoj kev siv dej
Kev faib tawm yog qhia hauv daim duab 3. Daim duab 3 (e) qhia qhov tsis sib xws coefficient ntawm nruab nrab ntu ntawm fiber ntau nqus coefficient yog siab dua ob sab, kom ntseeg tau tias qhov kub ntawm qhov sib faib yog qhov sib txawv, cov zis hluav taws xob yog tib yam li hauv daim duab 3 (d) thaum qhov xav tau fiber ntau yog luv luv los ntawm ntau tshaj 20m; Daim duab 3 (f) yuav muab lub zog tso rau hauv xya ntu, qhov kub thiab txias yog qhov sib txawv dua, thiab qhov kub thiab txias tuaj yeem tswj tau ntau yam zoo tagnrho. Txoj kev siv dej yog qhov tseem ceeb heev rau fiber ntau lasers. 2011 Jena University tau tsim ib kilowatt-scale side pumping fiber laser siv faib sab siv fiber ntau, 2014 SPI launched ib kilowatt-scale side pumping fiber laser khoom, nyob rau hauv 2015, Tuam Tshoj qhia tias National University of Defense Technology thiab nees nkaum-peb tshawb fawb lub koom haum. ntawm Tuam Tshoj Electronics Technology Group koom ua ke tsim ib qho kev faib sab-coupled cladding siv fiber ntau, thiab ua ib qho kev faib sab-coupling fiber laser nrog cladding siv fiber ntau. cladding twj siv fiber ntau, thiab ua kom muaj lub zog fiber ntau hauv zos, ua tiav cov zis hluav taws xob kilowatt. Kev siv ntau ntu tsis siv cov twj tso kua mis los yog cov qauv siv sab nraud tuaj yeem ua kom ntseeg tau tias qhov kub thiab txias ntawm cov fiber ntau tsis sib xws, txo qhov cuam tshuam ntawm thermal teebmeem thiab txo qhov ntev ntawm fiber ntau. Txawm li cas los xij, faib sab siv cov fiber ntau rub, txo cov fusion coupling poob ntawm txhua ntu ntawm fiber ntau thiab kev txhim kho kev ua tau zoo yog tus yuam sij rau kev siv tshuab. Nrog rau kev tawg thiab kev loj hlob ntawm cov thev naus laus zis tseem ceeb xws li kev tsim fiber ntau, rub thiab fusion splicing, ntau txoj kev siv dej yuav raug siv rau hauv kev tsim cov fiber ntau fiber ntau lasers, uas tuaj yeem ua ke nrog cov cuab yeej siv hluav taws xob sab nraud kom zoo cuam tshuam cov tiam ntawm thermal teebmeem hauv fiber ntau thiab ua tiav cov khoom ruaj khov ntawm cov lasers siab dua.
3.3 Kub dissipation tsim
Thermal conduction, thermal convection thiab thermal hluav taws xob yog peb txoj hauv kev ntawm kev hloov hluav taws xob, vim qhov coefficient ntawm thermal hluav taws xob me me, nws cov kev cuam tshuam tuaj yeem tsis quav ntsej feem ntau, conduction thiab convection yog cov txheej txheem kub dissipation. Rau lub zog me me fiber ntau laser, feem ntau tsuas yog xav txog fiber ntau natural convection tshav kub dissipation, thermal hluav taws xob muaj kev cuam tshuam tsawg dua, tuaj yeem txiav txim siab tsim nyog.
Convection tshav kub hloov feem ntau suav nrog ntuj convection tshav kub hloov thiab yuam convection hloov tshav kub. Qhov kev txiav txim siab ntawm convective tshav kub dissipation yog qhov loj ntawm convective heat transfer coefficient. Lub convective tshav kub hloov coefficient h muaj feem xyuam rau cov kua dej, txaus tus nqi thiab convection cheeb tsam. Raws li pom nyob rau hauv Table 1, nyob rau hauv tib yam kev mob, yuam convection tshav kub hloov coefficient yog siab tshaj lub ntuj convection tshav kub hloov coefficient, dej convection tshav kub hloov coefficient yog ob peb zaug ntawm huab cua convection tshav kub hloov coefficient. Qhov loj dua qhov convective tshav kub hloov coefficient, qhov zoo dua qhov kub dissipation ntawm fiber. Ntuj cua convection tshav kub dissipation feem ntau yog siv nyob rau hauv qis zog fiber ntau laser.
Thaum lub fiber ntau laser outputs pua pua ntawm watts los yog kilowatts ntawm lub hwj chim, nws yog ib qhov nyuaj rau ua tau raws li cov cua kub dissipation yuav tsum tau los ntawm ntshiab convection txias, thiab nws yog tsim nyog los xaiv ib tug tshwj xeeb tshav kub conduction txoj kev los ua lub tshav kub ntawm lub fiber mus rau ib tug tshwj xeeb kub dab dej. , thiab tom qab ntawd ua kom muaj txiaj ntsig zoo ntawm cov khoom siv hluav taws xob los yog convection diffusion los ntawm lub dab dej kub. Cov duab sib cuag lossis ua tiav ntawm cov khoom siv kho qhov muag thiab lub dab dej kub tsis haum, raws li qhia hauv daim duab 4, thiab muaj cov voids ntawm kev sib cuag, uas yuav cuam tshuam cov cua sov. Lub ntsiab tseem ceeb cuam tshuam rau thermal conduction ntawm optical fiber ntau thiab lub dab dej kub yog qhov thermal tsis kam, uas yog ib qho kev ntsuas ntawm theem ntawm thermal conduction ntawm cov tshav kub hloov pauv.
Cov qauv theoretical ntawm thermal kuj ntawm optical fiber ntau thiab cov dab dej kub tuaj yeem ua kom yooj yim li
Qhov twg Ts yog qhov kub thiab txias ntawm fiber ntau, T∞ yog qhov kub ntawm lub dab dej, q ″ yog cov cua sov (W / m2), uas yog qhov piv ntawm thermal load q' (W / m) rau thaj tsam, Rcontact yog lub thermal tiv thaiv, Rcond yog thermal tsis kam ntawm qhov sib txawv txheej, L yog lub thickness ntawm qhov sib txawv txheej, k yog thermal conductivity ntawm cov khoom muab tub lim nyob rau hauv qhov sib txawv, thiab A yog qhov chaw ntawm lub tshav kub flux hla. . Los ntawm kev noj cov qauv saum toj no, nws tuaj yeem pom tau tias ua kom muaj qhov thermal me me tuaj yeem txo qhov kub ntawm cov khoom siv fiber ntau. Txij li cov huab cua ntawm ob qhov kev sib txuas lus muaj cov thermal conductivity tsawg heev (kair=0.026 W/mK), cov thermal kuj tuaj yeem txo tau zoo los ntawm kev sau cov khoom siv thermal interface (TIM) nrog cov thermal conductivity, thaum lub thickness ntawm qhov sib txawv L yog me npaum li sai tau.
Ntxiv nrog rau kev txo qis qhov sib txawv thiab ua kom cov thermal conductivity, qhov kub ntawm fiber ntau tuaj yeem txo los ntawm kev tswj cov duab ntawm lub dab dej kub. Feem ntau cov duab plaub, V-shaped thiab U-shaped notch heat sink qauv tau qhia nyob rau hauv daim duab 5. Lub thermal kuj ntawm peb qhov sib txawv zawj qauv rau lub melting point ntawm recoated fiber ntau tau soj ntsuam, thiab nrog rau lwm yam tsis zoo ib yam, U-puab. zawj nrog qhov luv tshaj plaws perimeter muaj qhov tsawg tshaj plaws thermal tsis kam thiab ua kom txias zoo dua, thaum lub V-shaped zawj nrog qhov ntev tshaj plaws perimeter muaj qhov loj tshaj plaws thermal tsis kam thiab txias txias, thiab qhov sib txawv tsis pom tseeb hauv kev siv tswv yim, thiab U-hom thiab V-hom qauv siv ntau zaus, thiab cov cua kub dissipation yog pom tseeb zoo dua li ntawm cov khoom siv hluav taws xob nkaus xwb.
Thaum lub laser fiber ntau ua haujlwm ntawm lub zog qis, nws tuaj yeem ua cua txias los ntawm semiconductor txias module (TEC) thiab lub dab dej kub, thiab thaum lub laser fiber ntau ua haujlwm ntawm lub zog siab dua, nws tuaj yeem ua dej txias kom ua haujlwm ruaj khov. kub. Li et al. thov TEC rau sab nraud cua txias ntawm EYDFL, thiab siv ob-kawg siv cov qauv siv TEC rau peripheral aluminium kub dab dej rau thawj 10.2 cm fiber ntau hauv kev ua haujlwm siab, thiab U-shaped zawj yog qhia hauv daim duab. . 12(a). U-shaped zawj yog qhia hauv daim duab 12(a). Qhov nkhaus xiav hauv daim duab 6(b) qhia txog qhov kub thiab txias ntawm cov fiber ntau hauv kev sib cuag nrog lub dab dej kub, thiab qhov nkhaus liab yog qhov ntsuas qhov ntsuas kub ntawm cov fiber ntau, thiab kev siv TEC thiab cov dab dej kub kom txo tau qhov kub thiab txias. cov fiber.
Rau lub zog loj fiber ntau laser, ntau cov kev tshawb fawb tau txais kev kho cua sov dissipation kom tau txais cov khoom siv hluav taws xob siab tshaj li kilowatt qib yam tsis muaj qhov cuam tshuam tsis zoo thiab qhov tshwm sim thermal puas, thiab kev tswj xyuas thermal zoo ua kom ruaj khov ntawm fiber ntau laser. Nyob rau hauv txoj kev tshawb no, fiber ntau cua sov dissipation yog tsuas yog nqa tawm los ntawm lub dav hlau winding thiab lub tog raj kheej winding, siv hlau kub dab dej nrog U-type los yog V-hom grooves engraved, thiab qhov sib txawv ntawm cov fiber thiab cov grooves yog sau nrog thermally conductive silicone. roj (thermal conductivity feem ntau ntau dua 2 W / mK) kom tshem tawm cov cua sov los ntawm kev siv dej txias, thiab nws cov qauv yog qhia hauv daim duab 7.
Nrog rau txoj kev loj hlob ntawm high-power fiber laser thermal tswj technology, semiconductor siv, fiber ntau txuas thiab cladding optical filtering thiab lwm yam tseem ceeb technologies, thermal nyhuv raws li ib tug ntawm cov bottlenecks nyob rau hauv lub hwj chim li yuav zoo tswj, thiab lub hwj chim ntawm lub fiber laser. yuav txhim kho txuas ntxiv mus. Nyob rau tib lub sijhawm, kev tswj xyuas thermal zoo kuj tseem tuaj yeem txhawb txoj kev loj hlob ntawm fiber ntau laser integrated ntim tshuab, kom lub zog fiber ntau laser tuaj yeem siv rau ntau qhov chaw ib puag ncig.
