Cimultrafast laserpart ib
Cov khoom tshwj xeeb ntawm ultrafastlasers
Lub sijhawm luv luv mem tes ntawm ultrafast lasers muab cov tshuab tshwj xeeb uas paub qhov txawv ntawm cov mem tes ntev lossis txuas txuas-yoj (CW) lasers. Txhawm rau tsim kom muaj cov mem tes luv luv, yuav tsum muaj qhov dav spectrum bandwidth. Cov duab mem tes thiab nruab nrab wavelength txiav txim siab qhov tsawg kawg nkaus bandwidth xav tau los tsim cov pulses ntawm ib lub sijhawm tshwj xeeb. Feem ntau, qhov kev sib raug zoo no tau piav qhia nyob rau hauv cov nqe lus ntawm lub sij hawm-bandwidth khoom (TBP), uas yog muab los ntawm cov ntsiab lus tsis meej. Lub TBP ntawm Gaussian mem tes yog muab los ntawm cov qauv hauv qab no: TBPGaussian = ΔτΔν≈0.441
Δτ yog lub sijhawm mem tes thiab Δv yog qhov zaus bandwidth. Hauv qhov tseeb, qhov sib npaug qhia tau hais tias muaj kev sib raug zoo ntawm spectrum bandwidth thiab mem tes ntev, txhais tau hais tias raws li lub sijhawm ntawm cov mem tes txo qis, qhov bandwidth yuav tsum tau ua kom cov mem tes nce. Daim duab 1 qhia txog qhov tsawg kawg nkaus bandwidth xav tau los txhawb ntau lub sijhawm sib txawv ntawm cov mem tes.
Daim duab 1: Yam tsawg kawg nkaus spectral bandwidth yuav tsum tau txhawb nqalaser pulsesntawm 10 ps (ntsuab), 500 fs (xiav), thiab 50 fs (liab)
Cov kev sib tw ntawm ultrafast lasers
Qhov dav spectral bandwidth, lub zog ncov, thiab lub sijhawm luv luv ntawm cov lasers ultrafast yuav tsum tau tswj kom zoo hauv koj lub cev. Feem ntau, ib qho ntawm cov kev daws teeb meem yooj yim tshaj plaws rau cov kev cov nyom no yog cov txiaj ntsig dav dav ntawm lasers. Yog tias koj tau siv cov mem tes ntev dua lossis txuas ntxiv-yoj lasers yav dhau los, koj cov khoom siv kho qhov muag uas twb muaj lawm yuav tsis tuaj yeem cuam tshuam lossis xa tag nrho bandwidth ntawm ultrafast pulses.
Laser puas pib
Ultrafast optics kuj tseem muaj qhov sib txawv thiab nyuaj rau kev tshawb nrhiav qhov kev puas tsuaj laser (LDT) piv rau ntau qhov chaw laser. Thaum optics muab raunanosecond pulsed lasers, LDT qhov tseem ceeb feem ntau yog nyob rau hauv qhov kev txiav txim ntawm 5-10 J / cm2. Rau ultrafast optics, qhov tseem ceeb ntawm qhov loj no yog qhov tsis hnov tsw ntawm, raws li LDT qhov tseem ceeb yog feem ntau nyob rau ntawm qhov kev txiav txim ntawm <1 J / cm2, feem ntau ze rau 0.3 J / cm2. Qhov kev hloov pauv tseem ceeb ntawm LDT amplitude nyob rau hauv lub sijhawm sib txawv ntawm cov mem tes yog qhov tshwm sim ntawm laser puas mechanism raws li cov mem tes ntev. Rau nanosecond lasers lossis ntev duapulsed lasers, lub ntsiab mechanism uas ua rau kev puas tsuaj yog thermal cua sov. Txheej thiab substrate cov ntaub ntawv ntawm lubcov khoom siv kho qhov muagnqus cov xwm txheej photons thiab cua sov rau lawv. Qhov no tuaj yeem ua rau distortion ntawm cov khoom siv lead ua lattice. Thermal expansion, cracking, melting thiab lattice strain yog cov thermal puas mechanisms ntawm cov nolaser qhov chaw.
Txawm li cas los xij, rau ultrafast lasers, lub sij hawm mem tes nws tus kheej yog sai dua lub sij hawm teev ntawm tshav kub hloov ntawm lub laser mus rau cov khoom lattice, yog li cov thermal nyhuv tsis yog lub ntsiab ua rau laser-induced puas. Hloov chaw, lub zog siab tshaj plaws ntawm lub laser ultrafast hloov cov txheej txheem kev puas tsuaj rau hauv cov txheej txheem nonlinear xws li multi-photon absorption thiab ionization. Qhov no yog vim li cas nws thiaj li tsis tuaj yeem nqaim qis LDT qhov ntsuas ntawm nanosecond mem tes rau ntawm cov mem tes ultrafast, vim tias lub cev lub cev ntawm kev puas tsuaj txawv. Yog li ntawd, nyob rau hauv tib yam kev mob ntawm kev siv (xws li, wavelength, mem tes ntev, thiab repetition rate), ib tug kho qhov muag ntaus ntawv nrog ib tug txaus LDT ntsuam xyuas yuav yog qhov zoo tshaj plaws kho qhov muag ntaus ntawv rau koj tej daim ntawv thov. Optics kuaj nyob rau hauv cov xwm txheej sib txawv tsis yog tus sawv cev ntawm qhov ua tau zoo ntawm tib lub optics hauv qhov system.
Daim duab 1: Mechanisms ntawm laser induced kev puas tsuaj nrog txawv mem tes ntev
Post lub sij hawm: Jun-24-2024