Yuav Ua Li Cas Ntsuas Laser Beam Zoo? (Part 2)

Beam Qualityyog ib qho ntawm cov tseem ceeb tsis tau ntawm laser beam yam ntxwv. Cov neeg feem ntau siv cov lus "siab ncaj ncees, siab ci, siab coherence" los piav txog cov yam ntxwv ntawm lub teeb ci laser, thiab lub laser linewidth txiav txim siab lub sijhawm ntawm lub laser coherence rau qee yam, lub zog laser muaj qhov cuam tshuam zoo nrog lub laser brightness. , thiab laser beam zoo yog ze ze rau lub laser directivity.

Yog li ntawd, laser beam zoo muaj qhov cuam tshuam tseem ceeb ntawm daim ntawv thov kev sib txuas lus laser, kev hloov hluav taws xob nyob deb, kev tsim laser, thiab lwm yam.

3. StrehlRate

Streller ratio yog txhais raws li qhov piv ntawm qhov deb-field ncov lub teeb siv ntawm qhov tseeb beam axis mus rau lub ncov lub teeb siv ntawm lub zoo tagnrho beam axis nrog tib lub zog thiab niaj hnub theem. Nws cov lus qhia yog:

SR≈exp (-(2πδΥ λ)2) (5)

Qhov twg, Δ- yoj aberration ntawm lub laser beam, λ- laser wavelength. Streller qhov piv ntawm qhov qhia txog lub teeb ci siab tshaj plaws ntawm qhov chaw nyob deb, uas nyob ntawm qhov yuam kev wavefront thiab tuaj yeem cuam tshuam qhov cuam tshuam ntawm wavefront distortion ntawm lub nqaj zoo.

Feem ntau siv nyob rau hauv atmospheric optics, nws yog tsuas yog siv los soj ntsuam cov kev ua tau zoo ntawm adaptive optics systems los txhim kho beam zoo.

Streelby SR plays lub luag haujlwm tseem ceeb hauv kev ntsuas qhov hloov kho qhov muag kho qhov cuam tshuam ntawm lub zog hluav taws xob laser riam phom tshuab. Lub zog hluav taws xob laser riam phom feem ntau yog muaj ob lub subsystems: high-zog laser thiab beam directional ntaus ntawv.

Thaum lub zog hluav taws xob laser riam phom muaj kev kho qhov muag kho qhov muag, tsuas yog cov nqaj zoo ntawm cov kab hluav taws xob tawm ntawm lub laser, cov nqaj zoo ntawm cov kab hluav taws xob tawm ntawm tus thawj coj ntawm cov nqaj, thiab cov nqaj zoo ntawm cov hluav taws xob zoo rau lub laser. lub hom phiaj saum npoo tsis txaus los cuam tshuam qhov kev txhim kho ntawm cov nqaj zoo ntawm qhov kev hloov pauv hauv lub zog qhov chaw thauj khoom ntawm lub zog siab laser, thiab cov nqaj zoo ntawm cov nqaj ua ntej thiab tom qab kev kho kom haum yuav tsum raug soj ntsuam.

SR yog siv los cuam tshuam cov nqaj zoo ntawm lub kaum sab xis ntawm theem, uas tuaj yeem cuam tshuam zoo dua qhov kev ua tau zoo ntawm kev hloov kho kom kho lub wavefront distortion. Los ntawm kev ntsuas thiab kev sib piv ntawm SR nyob rau hauv qhib thiab kaw lub voj voog ntawm kev hloov kho qhov muag, kev ua haujlwm ntawm kev hloov kho qhov muag tuaj yeem txheeb xyuas thiab txhais tau tias:

n=SRS 'n (6)

Cov qauv saum toj no tuaj yeem cuam tshuam txog kev kho qhov cuam tshuam ntawm wavefront distortion los ntawm kev hloov kho qhov muag. Nyob rau hauv lub kaw-voj kev khiav hauj lwm mob, lub adaptive optical system kuj muaj qhov teeb meem ntawm jitter, uas yuav cuam tshuam rau qhov zoo ntawm lub beam.

Raws li kev txheeb xyuas ntawm cov ntsiab lus tseem ceeb cuam tshuam rau kab teeb pom kev zoo, txoj kev xoom tawm tswv yim them nyiaj thiab kev them nyiaj wavefront distortion yog qhov tseem ceeb tshaj plaws rau kev tswj cov kab hluav taws xob zoo. Txawm li cas los xij, Strehl piv tsuas yog qhia txog lub teeb ci siab tshaj plaws ntawm qhov chaw kho qhov muag nyob deb, thiab tsis tuaj yeem muab lub teeb siv hluav taws xob cuam tshuam los ntawm kev siv hluav taws xob.

Tsis tas li ntawd, nws tsuas tuaj yeem cuam tshuam txog lub teeb pom kev zoo thiab tsis tuaj yeem muab cov lus qhia muaj txiaj ntsig zoo hauv kev tsim kho qhov muag.

4. M-factor

M2 yam ntawm laser beam zoo tau lees paub los ntawm thoob ntiaj teb optical zej zog thiab pom zoo los ntawm International Organization for Standardization (ISO). M2 yam dhau los ntawm cov kev txwv ntawm cov kab teeb pom kev zoo tshaj plaws, thiab nws yog qhov tseem ceeb heev los siv M2 yam raws li tus qauv ntsuas rau kev tswj kom zoo thiab pab tsim cov tshuab laser.

Txoj kev ntsuas M2 feem ntau yog siv rau cov kab teeb ci laser nrog kev siv hluav taws xob tas mus li hauv cov kab hluav taws xob uas tsim los ntawm cov lasers qis. Vim tias lub sijhawm thib ob ntawm lub nqaj yog siv los txheeb xyuas qhov dav ntawm lub nqaj, qhov ntsuas ntsuas yuav tsum tau siab.

Nyob rau hauv lub brightness formula, lub laser beam duav txoj kab uas hla yog siv los sawv cev rau lub luminance cheeb tsam ntawm lub teeb qhov chaw ΔS{{0}}λd2o, lub laser beam deb field divergence lub kaum sab xis yog siv los sawv cev rau lub kaum sab xis ntawm lub teeb. qhov chaw ΔΨ=14πθ2f, thiab cov khoom d0θf yog qhia los ntawm M2 yam, ces lub laser beam brightness mis qhia tau hais tias: B= pδs ·ΔΨ=P(M2)2· λ2(21) Cov yam ntxwv ntawm lub laser beam tuaj yeem qhia tau los ntawm ntau qhov tsis zoo, xws li lub zog, wavelength, thiab beam zoo. Lub beam zoo M2 yog ib qho tseem ceeb parameter rau characterize lub siab brightness thiab zoo spatial coherence ntawm lub laser beam.

Kev faib tawm ntawm lub teeb pom kev nyob rau hauv qhov chaw thiab qhov ntau zaus yog siv los sawv cev rau lub teeb pom kev zoo M2, uas yog, M2= 4πσs-σSv, nws tuaj yeem paub tias M2 yam tuaj yeem cuam tshuam cov yam ntxwv ntawm kev siv. faib thiab theem faib ntawm lub teeb teb]. Piv nrog rau lwm txoj kev ntsuam xyuas, qhov M2 qhov zoo tuaj yeem cuam tshuam cov ntsiab lus ntawm cov nqaj zoo, muaj zog thoob ntiaj teb, thiab muaj kev cuam tshuam txog kev faib tawm ntawm lub teeb siv.

Qhov tseem ceeb M2 tsis haum rau kev soj ntsuam cov nqaj zoo ntawm lub zog siab laser. Lub resonant kab noj hniav ntawm lub siab lub zog laser feem ntau tsis ruaj khov, thiab cov zis laser beam tsis zoo, yog li yuav tsis muaj "optical duav". Ntxiv mus, rau lub siab-zog laser beam nrog discrete zog faib, qhov chaw vojvoog xam los ntawm lub ntsiab lus ntawm lub sij hawm thib ob yog deb ntawm qhov tseeb. Qhov tshwm sim M2 qhov yuam kev yog qhov loj.

Qhov tseem ceeb M2 xav kom qhov kev siv zog ntawm cov kab hluav taws xob hla ntu tsis tuaj yeem muaj qhov siab, piv txwv li, rau "super-Gaussian beam" M2 yam tsis muaj feem xyuam.

Lub ntsiab txhais thiab ntsuas ntawm laser beam zoo yog tsim nrog tiam thiab kev loj hlob ntawm lasers. Tam sim no, lub ntsiab lus thiab kev ntsuas ntawm laser beam zoo tsis tau mus txog qhov kev pom zoo, thiab lawv nyob rau hauv lub xeev ntawm "kev tshawb fawb thiab siv". Txawm li cas los xij, nrog kev ua tiav ntawm laser science thiab kev nce qib ntawm thev naus laus zis, lub ntsiab lus thiab kev ntsuas ntawm cov nqaj zoo tseem tab tom ntsib ntau yam teeb meem tshiab thiab cov teeb meem.

Cov ntaub ntawv tiv tauj:

Yog tias koj muaj lus nug, thov hu rau peb. Txawm peb cov neeg muas zaub nyob qhov twg thiab peb cov kev xav tau yog dab tsi, peb yuav ua raws li peb lub hom phiaj los muab peb cov neeg siv khoom zoo, tus nqi qis, thiab kev pabcuam zoo tshaj plaws.