TSWV YIM RAU COV LUS FIBER LASER Daim Ntawv Thov
Cov lasers fiber ntau tau pom ib qho kev ua thiab tshawb nrhiav qhov twg nic: Nd: YAG lasers kim dhau los lossis muaj cov khoom ntom nti uas tsis tsim nyog (piv txwv li cov nqi loj M2). Cov neeg siv cov lasers fiber ntau yuav muaj kev txhawj xeeb nrog kev hloov pauv ntawm lawv cov khoom siv tam sim no ntawm cov khoom siv kho qhov muag lossis yuav ua li cas hais kom meej cov optics tshiab. Tsab xov xwm no hais txog cov kev txhawj xeeb thiab cov ntsiab lus tseem ceeb uas yuav tsum tau ua tshwj xeeb.
Cov lasers fiber ntau tau txais cov av hauv ntau qhov kev siv xws li drilling, welding, foil txiav, laser npav, thiab npliag micro-machining. Cov kws tshawb fawb tshawb nrhiav tseem pom tias lawv muaj txiaj ntsig zoo raws li cov peev txheej vim tias lawv cov hneev me me thiab tus nqi qis M2. Kev ua tiav ntawm cov lasers muaj raws li lawv cov kev sib xyaw ua ke ntawm cov yam ntxwv ntawm cov nqaj tsis muaj los ntawm lwm qhov chaw hauv tib lub voos kab ntsig: yeem CW lossis kev ua haujlwm pulsed, polarization tswj (random, linear lossis ncig), nqaim spectral bandwidth, thiab TEM00 M2 qhov tseem ceeb nce 1 . Nrog xws li kev txhim kho ntawm M2 dhau Nd: YAG lasers, muaj peev xwm muaj zog dua tuaj yeem pom tau. Ntau txoj kab nrig ntom nti tau yog ua tau, uas ua rau lub ntsej muag tsis zoo rau cov cim thiab cov kis qis rau micromachining. Kev ua haujlwm ntawm qhov sib txawv ua haujlwm kuj tseem nce ntxiv. Yog li, lub khw lag luam xav kom muaj kev xav tau ntau zuj zus hauv cov khoom siv kho qhov muag tau tsim los rau cov ntawv thov fiber ntau.
1 Qhov Teeb Meem Ntawm Beam Zoo
Cov txheej txheem xaiv cov txheej txheem hnyav ncawv rau ntawm qhov muaj zog loj qhov ua tau tiav nrog cov lasers. Cov kab ke kho qhov muag ntawm lub ntsej muag hluav taws xob yog cov xim fiber ntau uas tuaj yeem tsim los txo cov qauv ntau, yog li tso cai cov tuam txhab tsim cov lag luam lasers nrog M2 = 1.05. M2 yog qhov sib piv ntawm lub laser nqaj lub multimode inch-divergence khoom rau lub zoo tagnrho diffraction txwv (TEM00) nqaj kab-divergence khoom:
Qhov twg Θ0 yog lub nqaj divergence nyob rau hauv milliradians thiab w0 yog qhov dav ntawm cov zis nqaj duav (yog tias qhov nqaj ncig, ces w0 tuaj yeem hloov los ntawm cov nqaj deter). Los yog rau qhov ua tau focal qhov taub d0:
Daim duab 1 piav qhia qhov txwv siv nyob rau hauv kab zauv (2). Fiber laser manufacturers feem ntau muab nqaj xa lub taub hau nrog qhov sib txuam tsim tawm ntawm 5mm mus rau 20mm inch (D0). Cov kev laij lej qhia tau tias qhov theoretical focal spot inch d0 ntawm 10μm yog ua tau nrog 19mm focal ntev lens. Yog li no, rau 50W fiber ntau laser ntawm 1075nm, cov nqaj tsom tau ntim zoo kawg nkaus uas pom tau tias lub zog muag ceev
Ntau cov sib xyaw ua ke tau muab nyob rau hauv cov lus 1. Thaum lub nqaj kauj optics yuav tsis pom muaj qhov chaw zoo meej, muaj qhov muaj kev nyab xeeb uas tus qauv tsim qauv xav saib xyuas; cov siab, qhov txawv txav ntawm qhov tsis muaj zog ntau yuav cuam tshuam rau cov khoom siv kho qhov muag thaum ua kom haum.
Rau qis lub zog pulsed fiber lasers thiab nruab nrab-ntau CW lasers (ntawm qhov kev txiav txim ntawm 1-5W nruab nrab lub zog), N-BK7 iav los ntawm Schott chott.de) yog qhov tsim nyog thiab pheej yig khoom siv substrate rau ob qho cuam tshuam thiab hloov pauv qhov muag qhov twg lub zog ntawm thaj chaw kho qhov muag yog <50mw> N-BK7 yog borosilicate yas kho qhov muag iav nrog cov qib siab thiab lub siab sib kis hauv qhov pom thiab ze-infrared. Cov tshuaj tiv thaiv kev tiv thaiv (AR) tuaj yeem siv rau ntawm qhov rais, lo ntsiab muag thiab tsom iav ib nrab kom nce tag nrho qhov kis tau tus mob los ntawm cov khoom siv. Ntawm cov zog no, xws li nqaim ("V"-co) AR txheej txheej los yog txheej txheej dav dav AR txheej txheej tau siv los txo qhov chaw ntawm qhov xav tau los ntawm thaj tsam li 4% mus rau <0.25% ntawm="" ib="" lub="" yoj="" yoj="" lossis=""><0.5% dhau="" ntawm="" qhov="" bandwidth="" ntawm="" 250-400nm="" rau="" cov="" teeb="" tsa="" tau="" kho="" laser="" (saib="" daim="" duab="">
Nqaim "V"-lub tsho muaj ntau-txheej (feem ntau ob-txheej) dielectric los tiv thaiv kev tiv thaiv kom pom kev ua tiav qhov theoretical qhov cuam tshuam tsawg kawg ntawm kev nqaim ntawm lub yoj yoj. Kev nce siab yuav nce siab rau ob sab ntawm qhov tsawg kawg nkaus uas muab nws "V" duab rau hauv kev cuam tshuam nrog kab hluav taws xob teeb. Cov tuam txhab Asmeskas feem ntau siv cov ntsiab lus "V-tsho" lossis "laserline" los qhia qhov sib txawv ntawm cov txheej txheej no los ntawm lawv cov dav dav AR.
Lwm cov khoom siv xaiv rau siv nrog 1-5W fiber ntau lasers yog N-SF11 iav los ntawm Schott uas muaj qhov ntsuas refractive n = 1.754 ntawm 1060 nm, siab dua ntawd ntawm N-BK7 (1.507). Qhov no muab qhov yooj yog tias lub lens nrog luv focal ntev yuav tsum rau daim ntawv thov. Vim tias ob qho tib si N-SF11 thiab N-BK7 muaj cov thermal expansion coefficients nyob rau hauv 8 × 10-6 / ° C ntau yam, fused silica yog qhov kev xaiv zoo dua ntawm cov khoom siv qis dua yog tias thermal stability tseem ceeb. Fused silica muaj qhov ua kom nthuav dav thermal ntawm tsuas yog 0.57 × 10-6 / ° C, ib qho kev txiav txim ntawm qhov ntau dua ruaj khov dua li lwm cov khoom siv kho qhov muag. Fiber laser tuam txhab pom zoo fused silica rau transmissionsive optics rau siv nrog cov laser fiber ntau cov zis ntau dua 50W. Piv txwv li, Southampton Photonics, Inc. pioptics.com) xav pom zoo kom siv cov xov xwm fused silica rau kev thov laser fiber ntau vim tias nws qhov cuam tshuam loj dua laser kev puas tsuaj. Nws muaj cov khoom sib hloov zoo ib yam rau N-BK7 los ntawm 500-2000nm, tab sis muaj ntau qhov ntsuas kub kom ruaj thiab muaj cov kev puas tsuaj ntau dua rau ob qho tib si pulsed thiab CW. IPG Photonics pgphotonics.com) pom zoo IR qib fused silica rau cov lasers fiber ntau nyob rau saum toj 1kW. Ib zaug ntxiv, AR txheej txheej tuaj yeem siv los txo qhov kev rov ua kom zoo dua, tab sis rau cov zog siab dua nws yog qhov zoo tshaj plaws tsuas yog siv ntau txheej "V" -coat AR txheej txheej, uas tiv taus txog 1MW / cm2 lossis ntau dua.
2 Lo ntsiab muag
Hauv qee qhov kev siv, xws li kev kos duab ntawm cov ntxiab kho qhov muag, tswj cov duab kom zoo thoob plaws txhua txoj kab teeb ci yog qhov tseem ceeb. Txawm hais tias singlet lo ntsiab muag, nyob hauv ob qho ntawm fused silica lossis N-BK7, tsim nyog rau cov ntawv thov yooj yim nqaj, cov doublet lossis triplet aplanatic lo ntsiab muag tuaj yeem tsim nyog dua thiaj li txo cov kis tau tus mob tsis zoo. Cov lo ntsiab muag no tau tsim los txo qis ob qho kev teeb tsa ntawm lub ntsej muag hu ua Spherical Aberration thiab Coma. Spherical Aberration yog axially symmetric thiab tshwm sim thaum collimated rays dhau los ntawm cov chaw sab nraud ntawm lub lens tsom rau ntawm qhov sib txawv deb ntawm lub lens dua li cov duab tshav dhau ntawm lub hauv cheeb tsam. Coma yog ib qho tawm ntawm-axis tsis-xaim wavefront distortion uas nce linearly nrog teb lub kaum sab xis lossis qhov deb ntawm tus thawj xibfwb. Hauv kev sib xyaw, cov kev ntxub ntxaug no ua rau sib hloov sib kis tau dhau ntawm lub lens thiab ua rau lub ntsej muag focal los ua cov duab tsis xwm yeem thiab / lossis qhov muag plooj.
Doublet thiab triplet lens tsim tuaj yeem siv cov khoom tawg yooj yim thaum yav dhau los lossis lwm yam khoom siv, nyob ntawm cov qauv tsim tshwj xeeb. Lawv tau ua kom zoo rau lub yoj yoj ib ntus thiab feem ntau ua rau huab cua sib zog los txo qis qhov sib txoom sib luag ua kom yuam kev los ntawm cov xis mas nyob nruab nrab ntawm cov iav. Huab cua sib xyaw cov ntsiab lus kuj tseem tso cai rau ntxiv qhov yooj yim hauv kev tsim vim tias cov chaw nyob ib sab tsis tas yuav tsum muaj qhov nkhaus sib xws. Hloov chaw, txhua qhov ntawm plaub mus rau rau saum npoo yuav tsum yoog tau zoo ntawm nws tus kheej txhawm rau ua kom zoo tshaj plaws kom tsis txhob hnov qab thiab ua tsis taus dab tsi los ntawm kev sib dhos ua tiav. Cemented lub rooj sib txoos yuav tsum zam kom thiaj li ua rau qhov loj qhov kev puas tsuaj tag nrho thiab kev cuam tshuam ntawm lub neej.
3 Nqaim Spectral Qhab Zog
Lub nthwv dej ntu ntawm cov roj carbon fiber yog txiav txim siab los ntawm qhov chaw tsim khoom siv cov twj tso kua mis thiab cov dopants siv hauv cov nquag fiber ntau kab noj hniav. Cov kab ke wavelength yog: 780-800nm rau cov kabmob doping,
1030-1120nm rau ytterbium, 1530-1600nm rau erbium-ytterbium, thiab 1800-2100nm rau thulium. Kev siv bandwidth ntawm ib lub fiber laser yog feem ntau txhais los ntawm fiber Bragg gratings. Cov tshuab laser fiber ntau yuav teev ntau yam, los ntawm qhov kawg tus neeg siv yuav xaiv tau ib lub yoj tshwj xeeb. Qhov tiag tiag bandwidth ntawm txhua lub laser tsuas yog 1-2nm. Qhov no tuaj yeem yog cov ncauj lus tseem ceeb thaum xaiv cov khoom siv xws li kev txiav txim siab dua ntab ntaws uas ua haujlwm kom tsuas yog dhau ntawm txoj kab nqaim.
4 Polarization Optics
Kev siv bandwidth thiab lub zog siv yog qhov tseem ceeb tshaj plaws cov nplaim teeb meem kom paub thaum xaiv ntawm ntau yam polarizers thiab nthwv dej. Polymer linear polarizers tsis yog siv rau kev siv hluav taws xob ntau dua 1W / cm2. Cemented lub voos xwmfab polarizers muaj nyob rau hauv ob qho tib si band nqaim thiab qhov qauv dav dav tab sis kev puas tsuaj ntawm kev cuam tshuam yog tsuas yog sab hauv epoxy. Txawm hais tias ob peb qhov kho qhov muag caws tau tshaj tawm tuaj yeem tiv cov kev siv laser lub zog ntawm 500W / cm2, cov tshuab fiber ntau laser pom zoo kom tsis txhob ua cov cemented optics rau cov lasers fiber ntau tshaj 50W. Saum toj no cov theem, nws yog qhov yuav tsum tau hloov mus rau qhov chaw huab cua lossis cov neeg sib chwv sab nrauv polarizing lub voos xwmfab tsim, uas feem ntau tuaj yeem tswj tau ntau dua 1 MW / cm2 ntawm CW laser teeb.
Rau ntau qhov kev txiav txim siab siv lead ua quartz waveplate ze ntawm 1 hli tuab, 2nm kev hloov pauv nyob rau hauv yoj yoj tuaj yeem ua qhov sib txawv ntawm ib qho zoo kawg nthwv dej thiab qhov tsis muaj qhov cuam tshuam. 1 hli tuab λ / 4 nthwv dej tsim los rau 1082nm tiag tiag yuav yog 0.23λ nthwv dej ntawm 1084nm, lossis λ / 50 tawm. Hloov pauv, qhov sib xyaw xoom xaj waveplate tsim rau tib ob nthwv dej yuav hloov hloov qeeb ntawm ob qho los ntawm <λ 1000="" vuag,="" uas="" zoo="" nyob="" rau="" hauv="" cov="" kev="" ntsuas="" ib="" txwm=""> Xoom kev txiav txim siab ntom nti ua haujlwm tau zoo heev tshaj ± 40-70nm los ntawm tus qauv nthwv dej, thiab tau zoo rau cov teeb tsa tau kho lub laser tau raws li cov neeg uas muaj lub laser kab bandwidth ntawm> 1nm (saib daim duab 3).
5 Daim iav
Cov txheej txheem txheem - piv txwv li cov txheej txheem uas twb muaj lawm - rau lwm cov kab laser yuav tsis phim zoo txaus rau cov kab hluav taws xob tshiab laser wavelengths thiab lub zog rau kev ua haujlwm zoo. Rau cov tshuab hluav taws xob tsis tshua muaj zog, tiv thaiv cov iav tiv thaiv cov xim xws li kub, txhuas thiab nyiaj tuaj yeem yog qhov kev xaiv tsim nyog rau qee yam kev siv qhov twg 100% kev cuam tshuam tsis tas. Lawv yooj yim muaj thiab pheej yig. Txawm li cas los xij, txawm tias nrog cov txheej txheej tiv thaiv, cov hlau xeb hlau yuav muag muag thiab thaum kawg yuav ua rau khawb los yog corroded yog tias tsis ua kom zoo. Hloov theej, multilayer dielectric tsom iav yog cov tawv-tawv, ruaj, thiab muaj kev cuam tshuam zoo ib yam thaum muaj xwm txheej lossis 45 ° (saib daim duab 4). Lawv muaj kev puas tsuaj zoo tshaj li ntawm 20J / cm2 hauv 10-20ns lub kaw lus pulsed thiab yog li yuav tsum tsis txhob thim lossis tsim kev puas tsuaj thaum siv nyob rau hauv tog twg los pulsed lossis CW fiber ntau laser teeb. Txawm hais tias tsis yog qhov dav dav, dielectric txheem iav tsim rau 1064nm Nd: YAG cov tshuab tseem yuav muaj kev cuam tshuam> 99% ntawm 1075nm lossis 1080nm.
6 Xaus
CVI tau tshaj tawm cov kab tshiab ntawm tsom iav tshwj xeeb uas tsim los siv nrog cov fiber ntau cov tshuab laser. Tsis tas li ntawd, CVI tau ntxiv cov roj carbon fiber ntau ntawm lub ntsej muag rau cov khoom uas twb muaj lawm suav nrog AR txheej txheej rau cov khoom siv sib tshooj, xws li nthwv dej, lo ntsiab muag, thiab qhov rais, ntxiv rau cov xim pleev xim rau cov kab teeb, cov tsom iav ib nrab, cov zis txuas, thiab cov tsom iav.
Cov lag luam tsim hluav taws xob laser txuas ntxiv mus thawb cov kev txwv ntawm lawv cov thev naus laus zis, nce CW-lub zog thiab lub zog kev lag luam muaj nyob. Cov kab teeb ci zoo tshaj plaws txuas nrog lub zog siab dua yuav txuas ntxiv ua qhov xav tau ntawm cov khoom siv kho qhov muag siv hauv cov kab ke no. Cov lus qhia tseem ceeb rau cov khoom siv no yuav suav nrog cov khoom tawg yooj yim, ua kev puas tsuaj thiab lub ntsej muag zoo.
