Yuav kom yaj cov ntaub ntawv ntawm ob sab ntawm qhov interface thiab tsim kom muaj kev sib txuas ntawm thaj tsam me me, qhov chaw tsom mus rau laser yuav tsum tau tsom mus rau ntawm cov qauv, uas ua rau muaj kev thov hnyav rau qhov tseeb ntawm lub tshuab vuam. Tsis tas li ntawd, vim yog qhov loj ntawm axial intensity gradient ntawm Gaussian beam tom qab tsom mus rau, qhov kub ntawm thaj chaw tsom mus rau tsis sib npaug, ua rau nws yooj yim tsim cov micro- thiab nano-void defects hauv thaj chaw cuam tshuam los ntawm laser, uas ua rau cuam tshuam rau qhov zoo ntawm cov qauv vuam.
Cov thev naus laus zis tsim lub teeb pom kev zoo siv tau los tsim cov kab teeb Bessel xoom kom zoo dua qhov kev faib tawm ntawm lub teeb pom kev zoo ntawm laser. Txoj hauv kev no txo qhov axial intensity gradient thiab txuas ntxiv qhov ntev ntawm lub teeb pom kev zoo, yog li ua rau qhov sib piv tob-rau-dav ntawm thaj chaw thermal effect tsim los ntawm laser. Yog li ntawd, nws txo qhov yuav tsum tau ua kom raug ntawm lub tshuab vuam laser, txhim kho ob qho tib si vuam zoo thiab ua haujlwm tau zoo.
1. Kev Tsim thiab Kev Tsim Qauv ntawm Cov Beams Bessel Uas Tsis Diffraction
Xyoo 1987, Durnin thawj zaug tau tawm tswv yim txog lub teeb Bessel uas tsis muaj qhov sib txawv, uas qhia txog cov yam ntxwv tshwj xeeb uas tsis sib txawv: nws qhov kev faib tawm ntawm lub teeb transverse tseem tsis hloov pauv thaum lub sijhawm nthuav dav, thiab qhov loj ntawm qhov chaw nruab nrab yeej ib txwm nyob ze rau qhov txwv diffraction. Tsis tas li ntawd, cov teeb Bessel kuj qhia txog cov yam ntxwv kho tus kheej thaum lub sijhawm nthuav dav. Thaum qhov chaw nruab nrab raug thaiv, lub teeb nyob ib puag ncig yuav sib sau ua ke rau hauv nruab nrab kom "kho" qhov chaw nruab nrab. Cov lus qhia lej rau kev faib tawm ntawm lub teeb transverse ntawm lub teeb Bessel uas tsis muaj qhov sib txawv yog:
Hauv kev hais lus:
- J0 sawv cev rau qhov kev ua haujlwm Bessel xoom.
- r thiab φ yog cov ntsiab lus radial thiab angular coordinate, raws li.
- z yog qhov deb ntawm kev nthuav dav.
- Kr thiab Kz yog cov ntsiab lus transverse thiab longitudinal wavevector, feem.
Qhov chaw tseem ceeb ntawm lub teeb Bessel uas tsis muaj qhov ntsuas muaj peev xwm kaw tau zoo, ua rau muaj kev cuam tshuam ntawm TW/cm² lossis siab dua, uas tuaj yeem ua rau cov khoom nqus tsis sib xws. Qhov tseem ceeb tshaj, qhov tsis sib txawv ntawm cov teeb Bessel uas tsis muaj qhov ntsuas muab qhov tob dua ntawm kev tsom mus rau qhov tob dua thiab qhov sib txawv ntawm qhov sib txawv ntawm axial me dua, yog li tsim kom muaj qhov kub thiab txias sib npaug thiab tiv thaiv kev tsim cov qhov tsis zoo ntawm kev vuam.
Daim duab hauv qab no qhia txog kev sib piv ntawm qhov ntev ntawm Bessel beams thiab Gaussian beams nyob rau hauv tib lub peev xwm confinement. Bessel beams muaj qhov tob ntawm kev tsom mus rau thaum tswj hwm qhov transverse micron-level focal spot diameter.
Muaj ntau txoj hauv kev los tsim cov kab Bessel xoom, thiab peb txoj hauv kev tseem ceeb hauv qab no yog qhov siv tau:
Txoj Kev Siv Lub Qhov Rauv: Txoj kev siv lub qhov rauv, raws li lub npe qhia, cuam tshuam nrog kev siv lub qhov rauv los tsim cov teeb Bessel. Qhov no kuj yog thawj txoj kev ua tiav rau kev tsim cov teeb Bessel. Daim duab hauv qab no qhia txog txoj kev siv lub qhov rauv rau kev tsim cov teeb Bessel. Ib nthwv dej dav hlau raug cuam tshuam rau ntawm lub qhov rauv los ntawm sab laug thiab kev diffraction tshwm sim.
Tom qab ntawd, lub lens zoo ua qhov Fourier transform, ua rau muaj Bessel beam tom qab lub lens. Qhov kev nthuav dav tsis sib txawv Zmax muaj feem cuam tshuam nrog lub cheeb d ntawm lub annular slit thiab lub qhov aperture ntawm lub lens.
Txawm hais tias txoj kev no tuaj yeem tsim cov kab teeb Bessel xoom, qhov kev hloov pauv hluav taws xob qis heev, ua rau nws nyuaj rau siv rau hauv cov teb ua laser.
Txoj Kev Hloov Lub Teeb Chaw: Cov txheej txheem tsim ntawm lub teeb Bessel xoom-order yog qhov tseem ceeb ntawm kev hloov pauv qhov faib theem ntawm lub teeb. Yog li ntawd, lub teeb Bessel xoom-order kuj tseem tuaj yeem tsim tau siv lub teeb modulator chaw. Lub teeb modulator chaw yog ib hom khoom siv optoelectronic modulation uas tswj lub teeb pom kev zoo thiab kev faib theem los ntawm cov teeb liab hluav taws xob. Lub teeb Bessel xoom-order tuaj yeem tsim tau los ntawm kev siv lub lens theem conical, raws li pom hauv daim duab hauv qab no, rau lub vaj huam sib luag ua haujlwm ntawm lub teeb modulator chaw.
Txoj kev Axicon: Ib qho axicon yog ib qho ntawm cov khoom siv diffractive uas siv iav passive feem ntau rau kev tsim cov kab teeb Bessel. Thaum lub teeb Gaussian feem ntau tshwm sim thiab hla dhau lub axicon, nws qhov kev faib tawm theem raug hloov kho, hloov nws mus rau hauv lub teeb Bessel xoom yam tsis muaj kev poob zog, raws li pom hauv daim duab hauv qab no.
Vim tias tus nqi qis, yooj yim siv, thiab qhov ua rau laser puas tsuaj ntau ntawm cov iav axicons, nrog rau lawv cov kev siv hluav taws xob zoo heev, axicons yog qhov kev xaiv tseem ceeb rau kev tsim cov ultrashort pulse Bessel beams hauv thaj chaw ntawm kev ua laser. Daim duab hauv qab no qhia txog daim duab qhia txog qhov nqaim ntawm lub teeb thiab kev sib kis ntawm lub teeb Bessel xoom. Los ntawm kev kho qhov loj me thiab kev taw qhia ntawm 4f imaging system, qhov deb ntawm kev nthuav dav tsis-diffractive, lub kaum sab xis ib nrab, thiab lub kaum sab xis hauv qhov kev taw qhia ntawm lub teeb Bessel tuaj yeem tswj tau yooj yim.
Thaum lub teeb Bessel xoom-order nrog lub kaum sab xis ib nrab ntawm Ư1 thiab qhov deb ntawm kev nthuav dav tsis muaj diffraction ntawm Zmax hla dhau lub kaw lus 4f uas muaj lub lens (L1) thiab lub lens lub hom phiaj (L2), qhov ntev ntawm cov duab geometric yuav raug nias ntxiv. Qhov kev loj hlob sab nraud yog kwv yees li M = f1 / f2 = 5, thiab qhov kev loj hlob ntev yog kwv yees li M2 = 25. Yog li, daim duab kawg ntawm lub teeb Bessel xoom-order hauv cov qauv tuaj yeem sawv cev los ntawm cov kev ntsuas geometric:
Cov qauv geometric ntawm Bessel beam duab sab hauv cov qauv iav quartz nyob rau hauv ntau lub kaum sab xis sib txawv thiab beam compression magnifications.
| lub kaum sab xis ntawm lub kaum sab xis α (°) | Lub teeb tawm tswv yim d(mm) | (um) | M=f1/f2 | Ư2 (°) | Zmax2 | |
| 0.5 | 3.8 | 1.03 | 20 | 3.1 | 3504 | 10.04 |
| 0.5 | 3.8 | 1.03 | 30 | 4.7 | 1555 xyoo | 6.7 |
| 0.5 | 3.8 | 1.03 | 40 | 6.2 | 873 | 5.02 |
| 0.5 | 3.8 | 1.03 | 50 | 7.8 | 558 | 4.02 |
| 1 | 3.8 | 1.03 | 20 | 6.2 | 1747 xyoo | 5.02 |
| 1 | 3.8 | 1.03 | 30 | 9.3 | 772 | 3.36 |
| 1 | 3.8 | 1.03 | 40 | 12.4 | 432 | 2.52 |
| 1 | 3.8 | 1.03 | 50 | 15.5 | 274 | 2.04 |
| 2.5 | 3.8 | 1.03 | 20 | 15.5 | 684 | 2.04 |
| 2.5 | 3.8 | 1.03 | 30 | 23.3 | 294 | 1.38 |
| 2.5 | 3.8 | 1.03 | 40 | 38.83 | 94.4 | 0.86 |
Kev faib tawm ntawm qhov muaj zog ntawm lub zog ntawm Bessel beam
- r thiab z: Cov khoom sib koom ua ke radial thiab axial, raws li.
- λ: Qhov nruab nrab ntawm lub laser.
- w: 1/e² lub vojvoog ntawm qhov teeb meem Gaussian beam.
- P0: Lub zog siab tshaj plaws ntawm lub laser ultrashort pulse.
- β1: Lub kaum sab xis ib nrab ntawm lub Bessel beam tom qab lub beam compression.
- k: Lub voj voog ntawm nthwv dej.
- J0: Kev ua haujlwm Bessel xoom.
Kev faib tawm ntawm lub zog ntawm lub teeb Bessel uas tsis muaj qhov ntsuas sab hauv iav quartz: Sab laug yog qhov faib tawm ntawm lub zog pom kev raws li qhov kev taw qhia thiab qhov pom ntawm qhov seem, thiab sab xis yog qhov faib tawm ntawm lub zog pom kev raws li qhov axis thiab qhov pom ntawm qhov seem.
2. Cov yam ntxwv ntawm Femtosecond Pulse Bessel Beam hauv Fused Silica Glass
Daim Duab (a) qhia cov duab me me ntawm kev sib cuam tshuam ntawm femtosecond pulse Bessel beams thiab fused silica iav ntawm ntau lub zog pulse. Lub laser pulse dav yog kho ntawm 220 fs, thiab lub kaum sab xis ib nrab ntawm Bessel beam sab hauv tus qauv yog 12.4 °. Nws tuaj yeem pom tias thaj chaw cuam tshuam laser qhia txog cov qauv linear ib-seem. Thaum lub zog laser pulse tsawg dua 9.5 μJ, qhov refractive index ntawm cov khoom siv hauv thaj chaw focal nce ntxiv, tshwm sim ua thaj chaw dub hauv micrograph.
Thaum lub zog laser pulse tshaj 9.5 μJ, qhov refractive index ntawm cov khoom siv hauv thaj chaw focal txo qis, tshwm sim ua thaj chaw dawb hauv micrograph, thiab qhov ntev ntawm thaj chaw dawb nce nrog kev nce zog pulse. Los ntawm kev txhuam cov qauv, peb tau pom cov yam ntxwv morphological ntawm thaj chaw dawb ntawm lub zog pulse ntawm 15.4 μJ nyob rau hauv lub scanning electron microscope, raws li pom hauv Daim Duab (b). Nws tuaj yeem xaus lus tias ib qho nanopore nrog lub cheeb tsam ntawm kwv yees li 200 nm yog tsim nyob rau hauv thaj chaw nrog qhov txo qis refractive index.
Los ntawm kev siv cov ion beam etching thiab in-situ scanning electron microscope observation systems, peb tau lees paub ntxiv tias muaj cov nanopore (Daim Duab c). Yog li ntawd, txhawm rau kom txo qhov tshwm sim ntawm cov teeb meem laser, lub zog ib zaug yuav tsum tsis pub tshaj 9.5 μJ thaum lub sijhawm laser welding.
3. Ua tiav qhov zoo Micro-Welding ntawm Fused Silica Glasses siv Bessel Ultrashort Pulse Laser.
Daim Duab (a) qhia txog daim duab micrograph saib saum toj ntawm qhov chaw vuam ntawm cov qauv. Nws tuaj yeem pom tias cov kab laser vuam yog sib xws thiab du. Txawm hais tias tseem muaj qee qhov tsis zoo ntawm cov qhov me me hauv thaj chaw vuam, tag nrho, nws zoo dua li Gaussian laser vuam kab. Kev ntsuas qhia tau tias qhov dav ntawm cov kab vuam yog kwv yees li 18 μm, thiab qhov sib nrug ntawm cov kab vuam yog 40 μm. Daim Duab (b) qhia txog daim duab micrograph saib sab ntawm cov qauv kab vuam.
Nws tuaj yeem pom tias qhov sib txawv ntawm cov qauv ploj mus tag tom qab ua laser, thiab cov khoom siv ze ntawm qhov interface tau sib xyaw ua ib qho tom qab dhau los ntawm cov txheej txheem thermal melting-cooling. Kev ntsuas qhia tau tias qhov tob ntawm thaj chaw thermal melting uas laser ua rau ncav cuag txog li 227 μm. Qhov no qhia tau tias thaum lub sijhawm laser vuam nrog cov kev ntsuas no, qhov tob axial ntawm qhov chaw focal tuaj yeem ncav cuag txog li 227 μm, uas yog plaub npaug ntawm Gaussian laser vuam nyob rau hauv tib qho xwm txheej.
4. Yuav cov iav Bessel qhov twg?
Wavelength Opto-Electronic muaj cov iav Bessel zoo uas siv rau hauv cov ntawv thov ua laser. Qhov kev hloov kho ntawm qhov tob ntawm qhov pom ntawm lub teeb tso zis los ntawm kev kho qhov loj ntawm lub qhov nkag ntawm lub teeb yog qhov zoo nkauj tshaj plaws ntawm lub kaw lus Bessel beam optical no.
| Tshooj No. | Qhov ntev ntawm lub zog (nm) | Ua Haujlwm Nrug Deb (hli) | Max Input Beam Dia (hli) | Tsim Qhov Tob Ntawm Kev Pom Kev (hli) | Tag Nrho Ntev (hli) |
|---|---|---|---|---|---|
| BESL-355-D10-T1 | 355 | 15.50 | 10 | 1.0 | 377.00 |
| BESL-532-10-D10 | 532 | 11.86 | 10 | 1.5 | 202.84 |
| BESL-1064-D10-T2 | 1064 | 10.80 | 10 | 2.0 | 238.00 |
| BESL-1064-D20-T12 | 1064 | 15.00 | 20 | 12.0 | 315.05 |
Lub sijhawm tshaj tawm: Lub Kaum Hli-10-2024