Lub Ntsiab Cai ntawm Laser Generation

Vim li cas peb thiaj li yuav tsum paub txog lub hauv paus ntsiab lus ntawm lasers?

Paub txog qhov sib txawv ntawm cov semiconductor lasers, fibers, discs, thiabYAG laserskuj tseem tuaj yeem pab kom nkag siab zoo dua thiab koom nrog kev sib tham ntau ntxiv thaum lub sijhawm xaiv tsa.

Tsab xov xwm no feem ntau tsom mus rau kev tshawb fawb nrov: kev qhia luv luv txog lub hauv paus ntsiab lus ntawm laser tiam, cov qauv tseem ceeb ntawm lasers, thiab ntau hom lasers.

Ua ntej, lub hauv paus ntsiab lus ntawm laser tiam

Laser yog tsim los ntawm kev sib cuam tshuam ntawm lub teeb thiab cov khoom, hu ua stimulated radiation amplification; Kev nkag siab txog stimulated radiation amplification yuav tsum nkag siab Einstein lub tswv yim ntawm spontaneous emission, stimulated absorption, thiab stimulated radiation, nrog rau qee qhov kev xav tseem ceeb.

Lub Hauv Paus Kev Xav 1: Qauv Bohr

Tus qauv Bohr feem ntau muab cov qauv sab hauv ntawm cov atoms, ua rau nws yooj yim to taub tias lasers tshwm sim li cas. Ib lub atom yog tsim los ntawm lub nucleus thiab electrons sab nraum lub nucleus, thiab cov orbitals ntawm electrons tsis yog arbitral. Electrons tsuas muaj qee qhov orbitals, ntawm cov uas lub orbital sab hauv tshaj plaws hu ua lub xeev av; Yog tias ib lub electron nyob hauv lub xeev av, nws lub zog yog qhov qis tshaj plaws. Yog tias ib lub electron dhia tawm ntawm lub orbit, nws hu ua thawj lub xeev excited, thiab lub zog ntawm thawj lub xeev excited yuav siab dua li ntawm lub xeev av; Lwm lub orbit hu ua lub xeev excited thib ob;

Qhov laj thawj uas ua rau laser tshwm sim yog vim tias cov electrons yuav txav mus rau hauv ntau qhov chaw sib txawv hauv cov qauv no. Yog tias cov electrons nqus lub zog, lawv tuaj yeem khiav los ntawm lub xeev av mus rau lub xeev zoo siab; Yog tias ib lub electron rov qab los ntawm lub xeev zoo siab mus rau lub xeev av, nws yuav tso tawm lub zog, uas feem ntau tso tawm hauv daim ntawv ntawm lub laser.

Lub Hauv Paus Kev Xav 2: Einstein Txoj Kev Xav Txog Kev Hluav Taws Xob Uas Muaj Kev Txhawb Nqa

Xyoo 1917, Einstein tau tawm tswv yim txog kev tsim hluav taws xob uas raug txhawb nqa, uas yog lub hauv paus kev xav rau lasers thiab kev tsim laser: kev nqus lossis kev tso tawm ntawm cov khoom yog qhov tshwm sim ntawm kev sib cuam tshuam ntawm lub tshav pob hluav taws xob thiab cov khoom me me uas tsim cov khoom, thiab nws lub hauv paus tseem ceeb yog kev hloov pauv ntawm cov khoom me me ntawm ntau qib zog. Muaj peb txoj hauv kev sib cuam tshuam ntawm lub teeb thiab cov khoom: kev tso tawm tsis tau npaj tseg, kev tso tawm raug txhawb nqa, thiab kev nqus tau raug txhawb nqa. Rau ib lub kaw lus uas muaj ntau cov khoom me me, peb txoj hauv kev no yeej ib txwm nyob ua ke thiab muaj feem cuam tshuam ze.

Kev tso tawm sai sai:

Raws li pom hauv daim duab: ib lub electron ntawm qib siab zog E2 hloov pauv mus rau qib qis zog E1 thiab tso tawm photon nrog lub zog ntawm hv, thiab hv = E2-E1; Cov txheej txheem hloov pauv tsis muaj feem cuam tshuam no hu ua kev hloov pauv tsis muaj feem cuam tshuam, thiab cov nthwv dej teeb uas tso tawm los ntawm kev hloov pauv tsis muaj feem cuam tshuam hu ua kev tawg hluav taws xob.

Cov yam ntxwv ntawm kev tso tawm yam tsis tau npaj tseg: Txhua lub photon yog ywj pheej, nrog rau cov lus qhia sib txawv thiab theem sib txawv, thiab lub sijhawm tshwm sim kuj yog random. Nws yog rau lub teeb tsis sib xws thiab chaotic, uas tsis yog lub teeb uas lub laser xav tau. Yog li ntawd, cov txheej txheem tsim laser yuav tsum txo qhov hom teeb pom kev no. Qhov no kuj yog ib qho ntawm cov laj thawj vim li cas qhov wavelength ntawm ntau lub lasers muaj lub teeb pom kev tsis tau npaj tseg. Yog tias tswj tau zoo, qhov sib piv ntawm kev tso tawm yam tsis tau npaj tseg hauv lub laser tuaj yeem raug tsis quav ntsej. Lub laser ntshiab dua, xws li 1060 nm, nws yog tag nrho 1060 nm, Hom laser no muaj qhov nqus dej thiab lub zog ruaj khov.

Kev nqus tau zoo:

Cov electrons ntawm qib zog qis (qis orbitals), tom qab nqus cov photons, hloov mus rau qib zog siab dua (qis orbitals), thiab cov txheej txheem no hu ua kev nqus tau. Kev nqus tau yog qhov tseem ceeb thiab yog ib qho ntawm cov txheej txheem twj tso kua mis tseem ceeb. Lub twj tso kua mis ntawm lub laser muab lub zog photon los ua rau cov khoom me me hauv qhov nruab nrab hloov pauv thiab tos kom muaj kev tawg hluav taws xob ntawm qib zog siab dua, tso tawm lub laser.

Kev tawg hluav taws xob uas raug txhawb nqa:

Thaum raug lub teeb ntawm lub zog sab nraud (hv = E2-E1), lub electron ntawm qib siab zog raug txhawb los ntawm lub photon sab nraud thiab dhia mus rau qib qis zog (lub voj voog siab khiav mus rau lub voj voog qis). Tib lub sijhawm, nws tso tawm lub photon uas zoo ib yam li lub photon sab nraud. Cov txheej txheem no tsis nqus lub teeb tsa thawj zaug, yog li yuav muaj ob lub photons zoo sib xws, uas tuaj yeem nkag siab thaum lub electron ntuav tawm lub photon uas tau nqus ua ntej, Cov txheej txheem luminescence no hu ua stimulated radiation, uas yog cov txheej txheem rov qab ntawm stimulated absorption.

Tom qab lub tswv yim meej lawm, nws yooj yim heev rau kev tsim lub laser, raws li pom hauv daim duab saum toj no: nyob rau hauv cov xwm txheej ib txwm muaj ntawm kev ruaj khov ntawm cov khoom siv, feem ntau ntawm cov electrons nyob hauv lub xeev av, cov electrons nyob hauv lub xeev av, thiab laser nyob ntawm cov hluav taws xob txhawb nqa. Yog li ntawd, cov qauv ntawm lub laser yog kom tso cai rau kev nqus hluav taws xob txhawb nqa kom tshwm sim ua ntej, coj cov electrons mus rau qib siab zog, thiab tom qab ntawd muab kev txhawb siab kom ua rau muaj ntau tus electrons qib siab zog kom dhau los ntawm cov hluav taws xob txhawb nqa, tso cov photons, Los ntawm qhov no, laser tuaj yeem tsim tau. Tom ntej no, peb yuav qhia txog cov qauv laser.

Cov qauv laser:

Txuas cov qauv laser nrog cov xwm txheej tsim laser uas tau hais ua ntej ib qho los ntawm ib qho:

Qhov xwm txheej ntawm qhov tshwm sim thiab cov qauv sib xws:

1. Muaj ib qho nruab nrab uas muab cov nyhuv amplification ua lub nruab nrab ua haujlwm laser, thiab nws cov khoom me me uas ua haujlwm muaj cov qauv qib zog uas tsim nyog rau kev tsim cov hluav taws xob txhawb nqa (feem ntau muaj peev xwm twj cov electrons mus rau cov orbitals muaj zog siab thiab muaj nyob rau ib lub sijhawm, thiab tom qab ntawd tso cov photons hauv ib qho pa los ntawm cov hluav taws xob txhawb nqa);

2. Muaj ib qho chaw txhawb nqa sab nraud (qhov chaw twj tso kua mis) uas tuaj yeem twj cov electrons los ntawm qib qis mus rau qib siab, ua rau muaj cov lej particle inversion ntawm qib siab thiab qis ntawm lub laser (piv txwv li, thaum muaj cov khoom me me muaj zog ntau dua li cov khoom me me muaj zog), xws li lub teeb xenon hauv YAG lasers;

3. Muaj ib lub qhov resonant uas tuaj yeem ua tiav laser oscillation, ua kom ntev ua haujlwm ntawm cov khoom siv laser ua haujlwm, tshuaj xyuas hom nthwv dej teeb, tswj qhov kev taw qhia ntawm lub beam, xaiv ua kom lub zog hluav taws xob txhawb nqa kom txhim kho monochromaticity (xyuas kom meej tias lub laser raug tso tawm ntawm qee lub zog).

Cov qauv sib xws tau qhia nyob rau hauv daim duab saum toj no, uas yog cov qauv yooj yim ntawm YAG laser. Lwm cov qauv yuav nyuaj dua, tab sis lub hauv paus yog qhov no. Cov txheej txheem tsim laser tau qhia nyob rau hauv daim duab:

Kev faib tawm laser: feem ntau yog cais los ntawm qhov nce nruab nrab lossis los ntawm daim ntawv zog laser

Kev faib tawm nruab nrab ntawm qhov nce:

Cov pa roj carbon dioxide laser: Qhov nruab nrab ntawm cov pa roj carbon dioxide laser yog helium thiabCO2 lasers,nrog lub laser wavelength ntawm 10.6um, uas yog ib qho ntawm cov khoom laser thaum ntxov tshaj plaws uas tau tsim tawm. Lub laser vuam thaum ntxov feem ntau yog raws li carbon dioxide laser, uas tam sim no feem ntau yog siv rau kev vuam thiab txiav cov khoom tsis yog hlau (ntaub, yas, ntoo, thiab lwm yam). Tsis tas li ntawd, nws kuj siv rau ntawm cov tshuab lithography. Carbon dioxide laser tsis tuaj yeem kis tau los ntawm cov fibers optical thiab mus ncig los ntawm txoj kev optical spatial, Lub Tongkuai thaum ntxov tshaj plaws tau ua tiav zoo, thiab ntau cov khoom siv txiav tau siv;

YAG (yttrium txhuas garnet) laser: YAG siv lead ua doped nrog neodymium (Nd) lossis yttrium (Yb) hlau ions yog siv ua laser nce nruab nrab, nrog rau qhov wavelength ntawm 1.06um. Lub YAG laser tuaj yeem tso zis siab dua, tab sis lub zog nruab nrab qis, thiab lub zog siab tshaj plaws tuaj yeem ncav cuag 15 npaug ntawm lub zog nruab nrab. Yog tias nws yog feem ntau yog lub laser pulse, qhov tso zis tas mus li tsis tuaj yeem ua tiav; Tab sis nws tuaj yeem xa mus los ntawm cov fibers optical, thiab tib lub sijhawm, qhov nqus ntawm cov khoom siv hlau nce ntxiv, thiab nws pib siv rau hauv cov khoom siv reflectivity siab, thawj zaug siv hauv 3C teb;

Fiber laser: Cov khoom siv tam sim no hauv kev ua lag luam siv ytterbium doped fiber ua qhov nce nruab nrab, nrog lub wavelength ntawm 1060nm. Nws tseem muab faib ua fiber thiab disc lasers raws li cov duab ntawm nruab nrab; Fiber optic sawv cev rau IPG, thaum disc sawv cev rau Tongkuai.

Semiconductor laser: Qhov nce nruab nrab yog semiconductor PN junction, thiab qhov wavelength ntawm semiconductor laser feem ntau yog ntawm 976nm. Tam sim no, semiconductor ze-infrared lasers feem ntau yog siv rau cladding, nrog cov teeb pom kev zoo tshaj 600um. Laserline yog ib lub tuam txhab sawv cev ntawm semiconductor lasers.

Faib raws li daim ntawv ntawm lub zog ua haujlwm: Pulse laser (PULSE), quasi continuous laser (QCW), continuous laser (CW)

Lub laser pulse: nanosecond, picosecond, femtosecond, qhov no high-frequency pulse laser (ns, pulse width) feem ntau tuaj yeem ua tiav lub zog siab tshaj plaws, high frequency (MHZ) processing, siv rau kev ua cov khoom sib txawv ntawm cov tooj liab thiab txhuas, nrog rau kev ntxuav feem ntau. Los ntawm kev siv lub zog siab tshaj plaws, nws tuaj yeem yaj cov khoom siv hauv paus sai sai, nrog lub sijhawm ua haujlwm tsawg thiab thaj chaw cuam tshuam me me ntawm cua sov. Nws muaj qhov zoo hauv kev ua cov khoom siv ultra-thin (qis dua 0.5 hli);

Quasi continuous laser (QCW): Vim yog qhov rov ua dua siab thiab lub voj voog ua haujlwm qis (qis dua 50%), qhov dav ntawm lub pulseQCW laserncav cuag 50 us-50 ms, sau qhov sib txawv ntawm kilowatt theem txuas ntxiv fiber laser thiab Q-switched pulse laser; Lub zog siab tshaj plaws ntawm quasi txuas ntxiv fiber laser tuaj yeem ncav cuag 10 npaug ntawm lub zog nruab nrab hauv kev ua haujlwm hom txuas ntxiv. QCW lasers feem ntau muaj ob hom, ib qho yog txuas ntxiv vuam ntawm lub zog qis, thiab lwm qhov yog pulsed laser vuam nrog lub zog siab tshaj plaws ntawm 10 npaug ntawm lub zog nruab nrab, uas tuaj yeem ua tiav cov ntaub ntawv tuab dua thiab vuam cua sov ntau dua, thaum tseem tswj cov cua sov hauv qhov ntau me me;

Laser Txuas Ntxiv Mus (CW): Qhov no yog qhov siv ntau tshaj plaws, thiab feem ntau ntawm cov lasers pom hauv khw yog CW lasers uas txuas ntxiv tso zis laser rau kev ua vuam. Fiber lasers raug muab faib ua ib hom thiab ntau hom lasers raws li cov kab uas hla ntawm lub hauv paus thiab cov yam ntxwv ntawm lub teeb, thiab tuaj yeem hloov kho rau ntau qhov xwm txheej ntawm daim ntawv thov.