Mu chilengezo chofunika kwambiri madzulo a pa Okutobala 3, 2023, Mphoto ya Nobel mu Fizikisi ya chaka cha 2023 idawululidwa, poyamikira zopereka zabwino kwambiri za asayansi atatu omwe adachita mbali zofunika kwambiri monga oyambitsa mu gawo la ukadaulo wa laser wa attosecond.

Mawu akuti "laser ya attosecond" amachokera ku nthawi yochepa kwambiri yomwe imagwira ntchito, makamaka motsatira dongosolo la attoseconds, lofanana ndi masekondi 10^-18. Kuti timvetse kufunika kwakukulu kwa ukadaulo uwu, kumvetsetsa kwakukulu kwa zomwe attosecond imatanthauza ndikofunikira kwambiri. Attosecond imayimira gawo la mphindi zambiri, ndikupanga gawo limodzi mwa magawo biliyoni a gawo limodzi mwa magawo biliyoni a sekondi mkati mwa sekondi imodzi. Kuti timvetse izi, ngati titayerekeza sekondi ndi phiri lalitali, attosecond ingakhale yofanana ndi mchenga umodzi womwe uli pansi pa phirilo. Mu nthawi yochepa iyi, ngakhale kuwala sikungadutse mtunda wofanana ndi kukula kwa atomu imodzi. Pogwiritsa ntchito ma laser a attosecond, asayansi amapeza mphamvu zosayerekezeka zowunikira ndikusintha mphamvu zovuta za ma elekitironi mkati mwa mapangidwe a atomu, mofanana ndi kubwerezabwereza pang'onopang'ono kwa chimango ndi chimango mu sewero la kanema, potero akufufuza momwe amagwirira ntchito.

Ma laser a AttosecondIzi zikuyimira mapeto a kafukufuku wochuluka komanso khama logwirizana la asayansi, omwe agwiritsa ntchito mfundo za kuwala kosakhala kolunjika kuti apange ma laser othamanga kwambiri. Kubwera kwawo kwatipatsa mwayi watsopano wowonera ndi kufufuza njira zosinthika zomwe zimachitika mkati mwa maatomu, mamolekyu, komanso ma elekitironi muzinthu zolimba.

Kuti timvetse bwino mtundu wa ma laser a attosecond ndi kuzindikira makhalidwe awo osazolowereka poyerekeza ndi ma laser achikhalidwe, ndikofunikira kufufuza momwe amagawidwira m'magulu osiyanasiyana "a m'banja la laser." Kugawa malinga ndi kutalika kwa mafunde kumaika ma laser a attosecond makamaka mkati mwa ma frequency a ultraviolet mpaka ma X-ray ofewa, kusonyeza kutalika kwawo kwa mafunde afupiafupi mosiyana ndi ma laser achikhalidwe. Ponena za njira zotulutsira, ma laser a attosecond amagwera m'gulu la ma laser oyendetsedwa, omwe amadziwika ndi nthawi yawo yochepa kwambiri ya pulse. Kuti tifanizire kumveka bwino, munthu akhoza kuganiza kuti ma laser oyendetsedwa mosalekeza ali ngati tochi yomwe imatulutsa kuwala kosalekeza, pomwe ma laser oyendetsedwa amafanana ndi kuwala kwa strobe, komwe kumasinthasintha mwachangu pakati pa nthawi zowunikira ndi mdima. Mwachidule, ma laser a attosecond amasonyeza khalidwe logunda mkati mwa kuwala ndi mdima, komabe kusintha kwawo pakati pa zikhalidwe ziwirizi kumachitika pafupipafupi modabwitsa, kufika ku gawo la ma attosecond.

Kugawa kwina ndi mphamvu kumaika ma laser m'mabraketi amphamvu zochepa, mphamvu yapakati, ndi mphamvu yapamwamba. Ma laser a Attosecond amapeza mphamvu yapamwamba kwambiri chifukwa cha nthawi yawo yochepa kwambiri ya pulse, zomwe zimapangitsa kuti mphamvu yayikulu kwambiri (P) - yomwe imatanthauzidwa ngati mphamvu ya mphamvu pa unit time (P=W/t). Ngakhale kuti ma pulse a attosecond laser payokha sangakhale ndi mphamvu yayikulu kwambiri (W), kutalika kwawo kochepa (t) kumawapatsa mphamvu yapamwamba kwambiri.

Ponena za madera ogwiritsira ntchito, ma laser amaphatikizapo ntchito zosiyanasiyana monga mafakitale, zamankhwala, ndi sayansi. Ma laser a Attosecond amapeza malo awo makamaka mu kafukufuku wa sayansi, makamaka pofufuza zinthu zomwe zikusintha mwachangu m'madera a fizikisi ndi chemistry, zomwe zimapatsa mwayi wowona momwe zinthu zikuyendera mwachangu padziko lapansi la microcosmic.

Kugawa magulu pogwiritsa ntchito laser medium kumatanthauza kuti ma laser ndi ma gas laser, solid-state lasers, liquid lasers, ndi semiconductor lasers. Kupanga ma attosecond lasers nthawi zambiri kumadalira pa gas laser media, kugwiritsa ntchito zotsatira za nonlinear optical kuti apange ma harmonics apamwamba.

Mu mafupipafupi, ma laser a attosecond amapanga gulu lapadera la ma laser afupifupi, omwe amadziwika ndi nthawi yawo yochepa kwambiri ya kugunda kwa mtima, yomwe nthawi zambiri imayesedwa mu ma attosecond. Zotsatira zake, akhala zida zofunika kwambiri pakuwonera ndikuwongolera njira zothamanga kwambiri za ma elekitironi mkati mwa ma atomu, mamolekyulu, ndi zinthu zolimba.

Njira Yabwino Kwambiri Yopangira Attosecond Laser

Ukadaulo wa laser wa Attosecond uli patsogolo pa zatsopano za sayansi, ndipo uli ndi zinthu zovuta kwambiri zomwe zingagwiritsidwe ntchito popanga. Kuti timvetse bwino zovuta za kupanga laser ya attosecond, tikuyamba ndi kufotokoza mwachidule mfundo zake, kutsatiridwa ndi mafanizo omveka bwino ochokera ku zochitika za tsiku ndi tsiku. Owerenga omwe sadziwa bwino zovuta za fizikisi yoyenera sayenera kutaya mtima, chifukwa mafanizo otsatirawa cholinga chake ndi kupangitsa kuti fizikisi yoyambira ya laser ya attosecond ipezeke mosavuta.

Njira yopangira ma laser a attosecond imadalira kwambiri njira yodziwika kuti High Harmonic Generation (HHG). Choyamba, kuwala kwa ma laser a femtosecond amphamvu kwambiri (masekondi 10^-15) kumayikidwa mwamphamvu pa chinthu chopangidwa ndi mpweya. Ndikofunikira kudziwa kuti ma laser a femtosecond, ofanana ndi ma laser a attosecond, ali ndi makhalidwe ofanana ndi kukhala ndi nthawi yochepa ya pulse komanso mphamvu yayikulu. Mothandizidwa ndi mphamvu ya laser, ma elekitironi omwe ali mkati mwa ma atomu a mpweya amamasulidwa kwakanthawi kuchokera ku ma atomu awo, ndikulowa pang'onopang'ono mu mkhalidwe wa ma elekitironi omasuka. Pamene ma elekitironi awa akusinthasintha poyankha mphamvu ya laser, pamapeto pake amabwerera ndikugwirizananso ndi ma atomu awo oyamba, ndikupanga mphamvu zatsopano.

Pa nthawiyi, ma elekitironi amayenda mofulumira kwambiri, ndipo akamalumikizana ndi atomiki, amatulutsa mphamvu yowonjezera mu mawonekedwe a mpweya wambiri wogwirizana, womwe umaonekera ngati ma photon amphamvu kwambiri.

Ma frequency a ma photon atsopano amphamvu kwambiri amenewa ndi ma integral multiple a ma frequency oyambirira a laser, kupanga zomwe zimatchedwa ma harmonics apamwamba, pomwe "harmonics" amatanthauza ma frequency omwe ndi ma integral multiple a ma frequency oyambirira. Kuti mupeze ma attosecond laser, kumakhala kofunikira kusefa ndikuyika ma harmonics apamwamba awa, kusankha ma harmonics enieni ndikuyika pamalo ofunikira. Ngati mukufuna, njira zochepetsera ma pulse zitha kufupikitsa nthawi ya pulse, ndikupanga ma pulses afupi kwambiri mu attosecond range. Mwachionekere, kupanga ma attosecond lasers kumakhala njira yotsogola komanso yophatikizana, yomwe imafuna luso lapamwamba komanso zida zapadera.

Pofuna kufotokoza momveka bwino njira yovutayi, tikupereka kufanana kophiphiritsira komwe kumachokera m'zochitika za tsiku ndi tsiku:

Mapulse a Laser a Femtosecond Olimba Kwambiri:

Tangoganizani muli ndi katapult wamphamvu kwambiri wokhoza kuponya miyala nthawi yomweyo pa liwiro lalikulu, mofanana ndi ntchito yomwe imachitidwa ndi ma pulse amphamvu kwambiri a femtosecond laser.

Zinthu Zopangira Mpweya:

Taganizirani za madzi odekha omwe akuyimira chinthu chochokera ku gasi, komwe dontho lililonse la madzi limayimira ma atomu ambirimbiri a gasi. Kuchita kwa miyala kulowa m'madzi awa mofananamo kumawonetsa momwe ma pulse amphamvu a femtosecond laser amakhudzira chinthu chochokera ku gasi.

Kusuntha ndi Kubwerezabwereza kwa Ma Electron (Kusintha Kwathupi):

Pamene ma pulse a laser a femtosecond amakhudza ma atomu a mpweya mkati mwa zinthu zomwe zimafuna mpweya, ma electron ambiri akunja amasangalala kwakanthawi komwe amachoka ku ma atomu awo, ndikupanga mkhalidwe wofanana ndi plasma. Pamene mphamvu ya dongosololi imachepa pambuyo pake (popeza ma pulse a laser amayendetsedwa mwachibadwa, okhala ndi nthawi zosiya), ma electron akunja awa amabwerera pafupi ndi ma atomu, kutulutsa ma photon amphamvu kwambiri.

Kupanga Harmonic Kwambiri:

Tangoganizirani nthawi iliyonse yomwe dontho la madzi limagwera pamwamba pa nyanja, limapanga ma ripples, monga momwe ma harmonics apamwamba amakhalira mu ma laser a attosecond. Ma ripples awa ali ndi ma frequency ndi amplitude apamwamba kuposa ma ripples oyamba omwe amayambitsidwa ndi primary femtosecond laser pulse. Panthawi ya HHG, kuwala kwa laser kwamphamvu, kofanana ndi kuponya miyala mosalekeza, kumaunikira cholinga cha gasi, chofanana ndi pamwamba pa nyanja. Mphamvu ya laser iyi imayendetsa ma elekitironi mu gasi, mofanana ndi ma ripples, kutali ndi ma atomu awo oyamba kenako nkuwakoka. Nthawi iliyonse elekitironi ikabwerera ku atomu, imatulutsa kuwala kwa laser kwatsopano komwe kumakhala ndi ma frequency apamwamba, kofanana ndi ma ripples ovuta kwambiri.

Kusefa ndi Kuyang'ana Kwambiri:

Kuphatikiza ma laser awa atsopano kumabweretsa mitundu yosiyanasiyana (ma frequency kapena ma wavelengths), ena mwa iwo amapanga attosecond laser. Kuti muthe kupeza kukula ndi ma frequency enaake, mutha kugwiritsa ntchito fyuluta yapadera, monga kusankha ma ripples omwe mukufuna, ndikugwiritsa ntchito galasi lokulitsa kuti liwayang'ane pamalo enaake.

Kupsinjika kwa Magazi (ngati kuli kofunikira):

Ngati mukufuna kufalitsa ma ripples mwachangu komanso mwachidule, mutha kufulumizitsa kufalikira kwawo pogwiritsa ntchito chipangizo chapadera, kuchepetsa nthawi yomwe ripple iliyonse imakhala. Kupanga ma laser a attosecond kumaphatikizapo njira zovuta zolumikizirana. Komabe, zikagawidwa ndikuwonetsedwa, zimakhala zosavuta kuzimvetsa.