A wata sanarwa mai muhimmanci da aka fitar a yammacin ranar 3 ga Oktoba, 2023, an bayyana kyautar Nobel a fannin kimiyyar lissafi ta shekarar 2023, inda aka yaba da gudummawar da masana kimiyya uku suka bayar wadanda suka taka muhimmiyar rawa a matsayin majagaba a fannin fasahar laser ta attosecond.

Kalmar "lasisin attosecond" ta samo asali ne daga ɗan gajeren lokacin da take aiki a kai, musamman a cikin tsarin attosecond, wanda ya yi daidai da daƙiƙa 10^-18. Domin fahimtar zurfin mahimmancin wannan fasaha, fahimtar abin da attosecond ke nufi yana da matuƙar muhimmanci. Attosecond yana tsaye a matsayin wani yanki na lokaci mai matuƙar nisa, wanda ya ƙunshi biliyan ɗaya na biliyan ɗaya na daƙiƙa a cikin faffadan mahallin daƙiƙa ɗaya. Don fahimtar wannan, idan muka kwatanta daƙiƙa ɗaya da babban dutse, attosecond zai yi kama da ƙwayar yashi guda ɗaya da aka gina a gindin dutsen. A cikin wannan tazara ta ɗan lokaci, har ma haske ba zai iya ratsawa da nisan da ya yi daidai da girman atom ɗaya ba. Ta hanyar amfani da lasers na attosecond, masana kimiyya suna samun damar da ba a taɓa gani ba don bincika da sarrafa yanayin electrons a cikin tsarin atom, kamar sake kunnawa a hankali a cikin tsarin sinima, ta haka suna zurfafa cikin hulɗarsu.

Lasers na Attosecondsuna wakiltar ƙarshen bincike mai zurfi da ƙoƙarin da masana kimiyya suka yi, waɗanda suka yi amfani da ƙa'idodin na'urorin gani marasa layi don ƙirƙirar lasers masu sauri. Zuwansu ya samar mana da wani sabon yanayi na lura da bincike kan hanyoyin da ke gudana a cikin ƙwayoyin halitta, ƙwayoyin halitta, har ma da electrons a cikin kayan aiki masu ƙarfi.

Domin fayyace yanayin lasers na attosecond da kuma fahimtar halayensu na yau da kullun idan aka kwatanta da lasers na gargajiya, yana da matuƙar muhimmanci a bincika rarrabuwarsu a cikin "iyalin laser." Rarrabawa ta hanyar tsawon rai yana sanya lasers na attosecond galibi a cikin kewayon ultraviolet zuwa mitoci masu laushi na X-ray, wanda ke nuna gajerun raƙuman su sabanin lasers na gargajiya. Dangane da yanayin fitarwa, lasers na attosecond suna faɗuwa ƙarƙashin rukunin lasers masu bugun zuciya, waɗanda aka siffanta su da ɗan gajeren lokacin bugun zuciya. Don zana kwatancen don haske, mutum zai iya hango lasers masu ci gaba kamar walƙiya da ke fitar da hasken haske mai ci gaba, yayin da lasers masu bugun zuciya suna kama da hasken strobe, suna canzawa cikin sauri tsakanin lokutan haske da duhu. A zahiri, lasers na attosecond suna nuna ɗabi'ar bugun zuciya a cikin haske da duhu, duk da haka sauyawarsu tsakanin yanayin biyu yana gudana a cikin mita mai ban mamaki, suna kaiwa ga sararin attosecond.

Ƙarin rarrabuwa ta hanyar wutar lantarki yana sanya lasers zuwa cikin maƙallan ƙarancin ƙarfi, matsakaici-ƙarfi, da kuma manyan ƙarfin. Lasers na Attosecond suna samun ƙarfin kololuwa mai girma saboda ɗan gajeren lokacin bugunsu, wanda ke haifar da ƙarfin kololuwa mai ƙarfi (P) - wanda aka ayyana a matsayin ƙarfin kuzari a kowane lokaci naúrar (P=W/t). Kodayake bugun laser na Attosecond guda ɗaya bazai iya samun babban kuzari ba (W), taƙaitaccen lokacinsu na lokaci (t) yana ba su ƙarfin kololuwa mai girma.

Dangane da fannonin amfani, lasers sun ƙunshi fannoni daban-daban da suka haɗa da aikace-aikacen masana'antu, likitanci, da kimiyya. Lasers na Attosecond galibi suna samun matsayi a cikin fannin binciken kimiyya, musamman a cikin binciken abubuwan da ke faruwa cikin sauri a cikin fannonin kimiyyar lissafi da sinadarai, suna ba da taga ga tsarin saurin saurin yanayin duniyar microcosmic.

Rarraba laser ta hanyar matsakaiciyar laser tana ƙayyade lasers a matsayin gas lasers, solid-state lasers, liquid lasers, da semiconductor lasers. Samar da attosecond lasers yawanci yana dogara ne akan gas laser media, yana amfani da tasirin gani mara layi don samar da jituwa mai girma.

A taƙaice, lasers na attosecond sun ƙunshi wani nau'i na musamman na lasers na gajerun bugun jini, waɗanda aka bambanta ta hanyar ɗan gajeren lokacin bugun jini, wanda yawanci ana auna shi a cikin daƙiƙa. Sakamakon haka, sun zama kayan aiki masu mahimmanci don lura da sarrafa ayyukan electrons masu sauri a cikin ƙwayoyin halitta, ƙwayoyin halitta, da kayan aiki masu ƙarfi.

Tsarin Samar da Laser na Attosecond Mai Tsada

Fasahar laser ta Attosecond tana kan gaba a cikin sabbin fasahohin kimiyya, tana da yanayi mai ban sha'awa ga samar da ita. Domin fayyace sarkakiyar samar da laser ta Attosecond, za mu fara da taƙaitaccen bayani game da ƙa'idodinta, sannan kuma misalai masu haske da aka samo daga abubuwan da suka faru na yau da kullun. Masu karatu waɗanda suka san sarkakiyar kimiyyar lissafi mai dacewa ba sa buƙatar yanke ƙauna, domin misalai masu zuwa suna nufin sa ilimin kimiyyar lissafi na laser ta Attosecond ya zama mai sauƙin samu.

Tsarin samar da lasers na attosecond ya dogara ne akan dabarar da aka sani da High Harmonic Generation (HHG). Da farko, hasken laser mai ƙarfi na femtosecond (daƙiƙa 10^-15) yana mai da hankali sosai kan kayan da ake nufi da iskar gas. Ya kamata a lura cewa lasers na femtosecond, kamar lasers na attosecond, suna da halaye na samun ɗan gajeren lokaci na bugun jini da ƙarfin kololuwa mai girma. A ƙarƙashin tasirin filin laser mai ƙarfi, electrons a cikin atoms na iskar gas suna 'yantar da su na ɗan lokaci daga ƙwayar atomic ɗinsu, suna shiga cikin yanayin electrons kyauta na ɗan lokaci. Yayin da waɗannan electrons ke juyawa a martanin filin laser, daga ƙarshe suna komawa zuwa kuma suna haɗuwa da ƙwayar atomic ta asali, suna ƙirƙirar sabbin yanayin kuzari mai girma.

A yayin wannan tsari, electrons suna motsawa a cikin sauri mai yawa, kuma idan aka haɗa su da ƙwayoyin atomic, suna fitar da ƙarin makamashi a cikin nau'in hayaki mai jituwa mai yawa, suna bayyana a matsayin photons masu ƙarfi.

Mitar waɗannan sabbin photons masu ƙarfi masu yawa da aka samar su ne ma'auni na mitar laser ta asali, suna samar da abin da ake kira harmonics masu girma, inda "harmonics" ke nuna mitoci waɗanda suka haɗa da ma'auni na mitar asali. Don samun lasers na attosecond, ya zama dole a tace kuma a mayar da hankali kan waɗannan ma'auni masu girma, a zaɓi takamaiman ma'auni da kuma mai da hankali kan wurin mai da hankali. Idan ana so, dabarun matse bugun jini na iya ƙara rage tsawon bugun, suna samar da bugun jini mai gajeru a cikin kewayon attosecond. Babu shakka, ƙirƙirar lasers na attosecond ya ƙunshi tsari mai zurfi da fannoni da yawa, yana buƙatar babban matakin fasaha da kayan aiki na musamman.

Domin bayyana wannan tsari mai rikitarwa, muna bayar da kwatancen kwatancen da aka gina bisa ga yanayin yau da kullun:

Haɗakar Laser ta Femtosecond mai ƙarfi:

Katapult mai ƙarfi sosai wanda zai iya jifa da duwatsu nan take cikin babban gudu, kamar rawar da bugun laser na femtosecond mai ƙarfi ke takawa.

Kayan da aka yi niyya da iskar gas:

Ka yi tunanin wani ruwa mai natsuwa wanda ke nuna kayan da ake nufi da iskar gas, inda kowace digo ta ruwa ke wakiltar tarin ƙwayoyin iskar gas. Aikin tura duwatsu cikin wannan jikin ruwa yana kama da tasirin ƙarfin bugun laser na femtosecond mai ƙarfi akan kayan da ake nufi da iskar gas.

Motsin Electron da Haɗawa (Canjin Jiki):

Lokacin da bugun laser na femtosecond ya shafi ƙwayoyin iskar gas a cikin kayan da ake nufi da iskar gas, adadi mai yawa na electrons na waje suna jin daɗin ɗan lokaci zuwa wani yanayi inda suka rabu da ƙwayoyin atomic ɗinsu, suna samar da yanayi kamar plasma. Yayin da kuzarin tsarin ke raguwa daga baya (tunda bugun laser ɗin yana da ƙarfi, yana nuna tazara na dakatarwa), waɗannan electrons na waje suna komawa kusa da ƙwayoyin atomic ɗin, suna fitar da photons masu ƙarfi.

Babban Tsarin Haɗin Kai:

Ka yi tunanin duk lokacin da digo na ruwa ya koma saman tafkin, yana haifar da ripples, kamar manyan harmonics a cikin lasers na attosecond. Waɗannan ripples suna da mitoci da girma mafi girma fiye da ripples na asali da bugun laser na femtosecond na farko ya haifar. A lokacin aikin HHG, wani haske mai ƙarfi na laser, kamar ci gaba da jefa duwatsu, yana haskaka abin da ake nufi da iskar gas, kamar saman tafkin. Wannan filin laser mai ƙarfi yana tura electrons a cikin iskar gas, kamar ripples, nesa da atoms na iyaye sannan ya ja su baya. Duk lokacin da electron ya koma ga atom, yana fitar da sabon hasken laser tare da mita mafi girma, kama da tsarin ripple mai rikitarwa.

Tacewa da Mayar da Hankali:

Haɗa duk waɗannan sabbin hasken laser da aka samar yana haifar da launuka daban-daban (mita ko tsawon tsayi), wasu daga cikinsu suna samar da laser attosecond. Don ware takamaiman girma da mitar ripple, zaku iya amfani da matattara ta musamman, kamar zaɓar ripples da ake so, kuma kuyi amfani da gilashin ƙara girma don mayar da hankali kan wani yanki na musamman.

Matsi na Pulse (idan ya cancanta):

Idan kana da niyyar yaɗa ripples cikin sauri da gajere, za ka iya hanzarta yaɗa su ta amfani da wata na'ura ta musamman, ta hanyar rage lokacin da kowace ripple ke ɗauka. Samar da lasers na attosecond ya ƙunshi haɗakar hanyoyin aiki masu rikitarwa. Duk da haka, idan aka wargaza shi aka kuma gani, zai zama mai sauƙin fahimta.