Cimultrafast laserntu ob
Dispersion thiab mem tes sib kis: pab pawg qeeb dispersion
Ib qho ntawm cov teeb meem nyuaj tshaj plaws uas tau ntsib thaum siv ultrafast lasers yog tswj lub sijhawm ntawm ultra-luv pulses pib tawm los ntawmlaser. Ultrafast pulses yog qhov cuam tshuam rau lub sij hawm distortion, uas ua rau cov pulses ntev. Qhov no tshwm sim zuj zus thaum lub sij hawm ntawm thawj zaug mem tes shortens. Thaum cov lasers ultrafast tuaj yeem tawm cov pulses nrog lub sijhawm ntawm 50 vib nas this, lawv tuaj yeem nthuav dav hauv lub sijhawm los ntawm kev siv cov iav thiab lo ntsiab muag kom xa cov mem tes mus rau qhov chaw lub hom phiaj, lossis tsuas yog xa cov mem tes los ntawm huab cua.
Lub sij hawm no distortion yog suav hais tias siv ib qho kev ntsuas hu ua pab pawg qeeb dispersion (GDD), tseem hu ua thib ob-order dispersion. Qhov tseeb, kuj tseem muaj cov lus txiav txim siab dua uas yuav cuam tshuam rau lub sijhawm faib ntawm ultrafart-laser pulses, tab sis hauv kev xyaum, nws yog feem ntau txaus los tshuaj xyuas cov nyhuv ntawm GDD. GDD yog ib tug zaus-nyob ntawm tus nqi uas yog linearly proportional rau thickness ntawm cov khoom muab. Transmission optics xws li lo ntsiab muag, qhov rais, thiab lub hom phiaj cov khoom feem ntau muaj qhov zoo GDD qhov tseem ceeb, uas qhia tau hais tias ib zaug compressed pulses tuaj yeem muab qhov kev sib kis ntawm optics ntev ntev dua li cov emissions.laser systems. Cheebtsam nrog qis zaus (piv txwv li, ntev wavelengths) propagate sai dua cov khoom uas muaj ntau dua frequencies (ie, luv wavelengths). Raws li cov mem tes dhau los ntawm ntau thiab ntau qhov teeb meem, lub wavelength hauv mem tes yuav txuas ntxiv mus ntxiv thiab ntxiv rau lub sijhawm. Rau luv luv mem tes ntev, thiab yog li ntawd dav bandwidths, cov nyhuv no yog ntxiv exaggerated thiab yuav ua rau lub sij hawm tseem ceeb mem tes distortion.
Ultrafast laser siv
spectroscopy
Txij li thaum lub advent ntawm ultrafast laser qhov chaw, spectroscopy yog ib qho ntawm lawv cov kev siv tseem ceeb thaj chaw. Los ntawm kev txo cov mem tes ntev mus rau femtoseconds lossis txawm attoseconds, cov txheej txheem dynamic hauv physics, chemistry thiab biology uas keeb kwm tsis tuaj yeem soj ntsuam tam sim no tuaj yeem ua tiav. Ib qho ntawm cov txheej txheem tseem ceeb yog atomic motion, thiab kev soj ntsuam ntawm atomic motion tau txhim kho txoj kev nkag siab ntawm cov txheej txheem tseem ceeb xws li molecular vibration, molecular dissociation thiab lub zog hloov mus rau hauv photosynthetic proteins.
bioimaging
Peak-power ultrafast lasers txhawb cov txheej txheem nonlinear thiab txhim kho kev daws teeb meem rau kev kuaj mob lom neeg, xws li multi-photon microscopy. Nyob rau hauv ntau lub tshuab hluav taws xob, txhawm rau tsim kom muaj lub teeb liab tsis sib xws los ntawm lub hom phiaj lom neeg lossis lub hom phiaj fluorescent, ob lub photons yuav tsum sib tshooj hauv qhov chaw thiab lub sijhawm. Cov txheej txheem nonlinear no txhim kho cov duab daws teeb meem los ntawm kev txo qis tom qab fluorescence cov cim qhia tias mob plague kev tshawb fawb ntawm ib leeg-photon txheej txheem. Cov teeb liab simplified keeb kwm yav dhau yog piav qhia. Qhov me me excitation cheeb tsam ntawm multiphoton microscope kuj tiv thaiv phototoxicity thiab minimizes kev puas tsuaj rau cov qauv.
Daim duab 1: Ib daim duab piv txwv ntawm txoj kab nqaj hauv kev sim ntau lub tshuab tsom iav
Laser cov khoom ua
Ultrafast laser qhov chaw kuj tau hloov kho laser micromachining thiab cov khoom siv vim yog txoj kev tshwj xeeb uas ultrashort pulses cuam tshuam nrog cov ntaub ntawv. Raws li tau hais ua ntej, thaum tham txog LDT, lub sijhawm ntev ntawm cov mem tes ultrafast yog sai dua li lub sijhawm teev ntawm cov cua kub diffusion mus rau hauv lub lattice ntawm cov khoom. Ultrafast lasers tsim ib qho chaw me me uas cuam tshuam rau tshav kub duananosecond pulsed lasers, ua rau qis incision poob thiab ntau precision machining. Lub hauv paus ntsiab lus no kuj tseem siv tau rau cov ntawv kho mob, qhov uas qhov kev txiav txim siab ntau ntxiv ntawm ultrafart-laser txiav pab txo qis kev puas tsuaj rau cov ntaub so ntswg thiab txhim kho cov neeg mob kev paub thaum lub sijhawm phais laser.
Attosecond pulses: yav tom ntej ntawm ultrafast lasers
Raws li kev tshawb fawb txuas ntxiv mus ua ntej ultrafast lasers, tshiab thiab txhim kho lub teeb pom kev zoo nrog lub sijhawm luv luv tau tsim. Txhawm rau kom nkag siab txog cov txheej txheem ntawm lub cev sai dua, ntau tus kws tshawb fawb tau tsom mus rau tiam ntawm attosecond pulses - txog 10-18 s nyob rau hauv huab ultraviolet (XUV) wavelength ntau. Attosecond pulses tso cai rau kev taug qab ntawm electron motion thiab txhim kho peb txoj kev nkag siab ntawm cov qauv hluav taws xob thiab quantum mechanics. Thaum kev koom ua ke ntawm XUV attosecond lasers rau hauv cov txheej txheem kev lag luam tseem tsis tau ua kom muaj kev vam meej, kev tshawb fawb tsis tu ncua thiab kev nce qib hauv lub tshav pob yuav luag yeej thawb cov thev naus laus zis no tawm ntawm chav kuaj thiab mus rau hauv kev tsim khoom, raws li tau ua nrog femtosecond thiab picosecond.laser qhov chaw.
Post lub sij hawm: Jun-25-2024