Ci gaba a fasahar hasken ultraviolet mai matuƙar tsanani

Ci gaba a cikin matsanancin ultravioletfasahar tushen haske

A cikin 'yan shekarun nan, majiyoyin harmonic masu tsananin ultraviolet sun jawo hankali sosai a fannin yanayin wutar lantarki saboda ƙarfin haɗin kai, ɗan gajeren lokacin bugun jini da kuma ƙarfin photon mai yawa, kuma an yi amfani da su a cikin nazarin spectral da hoto daban-daban. Tare da ci gaban fasaha, wannantushen haskeyana tasowa zuwa ga yawan maimaitawa, yawan kwararar photon, yawan kuzarin photon da kuma gajeriyar faɗin bugun jini. Wannan ci gaba ba wai kawai yana inganta ƙudurin aunawa na tushen hasken ultraviolet mai tsananin gaske ba, har ma yana samar da sabbin damammaki don ci gaban fasaha na gaba. Saboda haka, zurfafa bincike da fahimtar yawan maimaitawa mai yawan gaske tushen hasken ultraviolet mai tsananin gaske yana da matuƙar mahimmanci don ƙwarewa da amfani da fasahar zamani.

Don auna electron spectroscopy akan sikelin lokaci na femtosecond da attosecond, adadin abubuwan da aka auna a cikin haske ɗaya sau da yawa bai isa ba, wanda hakan ya sa ƙarancin hasken remixture ya kasa samun ƙididdiga masu inganci. A lokaci guda, tushen haske mai ƙarancin photon flux zai rage rabon sigina zuwa hayaniya na hoton microscopic a lokacin iyakancewar lokacin fallasa. Ta hanyar ci gaba da bincike da gwaje-gwaje, masu bincike sun yi ci gaba da inganta yawan amfanin ƙasa da ƙirar watsawa na yawan maimaitawa mai yawa hasken ultraviolet mai tsanani. An yi amfani da fasahar nazarin spectral mai ci gaba tare da babban maimaitawa mai yawa tare da babban maimaitawa mai yawa tushen hasken ultraviolet mai tsanani don cimma babban daidaito na tsarin abu da tsarin kuzari na lantarki.

Amfani da tushen hasken ultraviolet mai tsanani, kamar ma'aunin electron spectroscopy mai kusurwa (ARPES), yana buƙatar hasken ultraviolet mai tsanani don haskaka samfurin. Elektrons da ke saman samfurin suna motsawa zuwa yanayin ci gaba ta hanyar hasken ultraviolet mai tsanani, kuma Kusurwar kuzarin motsi da fitarwa ta photoelectrons tana ɗauke da bayanan tsarin band na samfurin. Mai nazarin electron tare da aikin ƙudurin Angle yana karɓar photoelectrons mai haske kuma yana samun tsarin band kusa da band na samfurin. Don ƙarancin maimaitawa mitar tushen hasken ultraviolet mai tsanani, saboda bugunsa guda ɗaya yana ɗauke da adadi mai yawa na photon, zai motsa adadi mai yawa na photoelectrons akan saman samfurin cikin ɗan gajeren lokaci, kuma hulɗar Coulomb za ta haifar da faɗaɗa sosai na rarraba kuzarin motsi na photoelectron, wanda ake kira tasirin cajin sarari. Domin rage tasirin tasirin cajin sarari, ya zama dole a rage photoelectrons da ke cikin kowane bugun yayin da ake kiyaye kwararar photon mai ɗorewa, don haka ya zama dole a tuƙalasertare da yawan maimaitawa mai yawa don samar da hasken ultraviolet mai matuƙar ƙarfi tare da yawan maimaitawa mai yawa.

Fasahar da aka inganta ta hanyar amfani da resonance tana samar da jimloli masu inganci a mitar maimaitawa ta MHz
Domin samun tushen hasken ultraviolet mai matuƙar ƙarfi tare da saurin maimaitawa har zuwa 60 MHz, ƙungiyar Jones a Jami'ar British Columbia da ke Burtaniya ta yi aikin samar da harmonic mai ƙarfi a cikin ramin haɓaka sautin magana na femtosecond (fsEC) don cimma tushen hasken ultraviolet mai matuƙar ƙarfi kuma ta yi amfani da shi ga gwaje-gwajen electron spectroscopy (Tr-ARPES) da aka warware lokaci-lokaci. Tushen hasken yana da ikon isar da kwararar photon fiye da lambobin photon 1011 a kowace daƙiƙa tare da harmonic guda ɗaya a ƙimar maimaitawa na 60 MHz a cikin kewayon kuzari na 8 zuwa 40 eV. Sun yi amfani da tsarin laser fiber mai amfani da ytterbium a matsayin tushen iri don fsEC, da kuma halayen bugun jini da aka sarrafa ta hanyar ƙirar tsarin laser na musamman don rage hayaniyar ambulan ɗaukar kaya (fCEO) da kuma kula da kyawawan halayen matse bugun zuciya a ƙarshen sarkar amplifier. Don cimma ingantaccen haɓakar sauti a cikin fsEC, suna amfani da madaukai guda uku na sarrafa servo don sarrafa amsawa, wanda ke haifar da daidaiton aiki a matakai biyu na 'yanci: lokacin tafiya da dawowa na zagayowar bugun jini a cikin fsEC ya dace da lokacin bugun jini na laser, kuma canjin lokaci na mai ɗaukar filin lantarki dangane da ambulan bugun jini (watau, matakin ambulan mai ɗaukar hoto, ϕCEO).

Ta hanyar amfani da iskar gas ta krypton a matsayin iskar gas mai aiki, ƙungiyar binciken ta cimma nasarar samar da harmonics masu girma a cikin fsEC. Sun yi ma'aunin graphite na Tr-ARPES kuma sun lura da saurin thermiation da kuma sake haɗuwa a hankali na yawan electrons waɗanda ba su da zafi, da kuma yanayin yanayin da ba su da zafi kai tsaye kusa da matakin Fermi sama da 0.6 eV. Wannan tushen haske yana ba da kayan aiki mai mahimmanci don nazarin tsarin lantarki na kayan aiki masu rikitarwa. Duk da haka, samar da harmonics masu girma a cikin fsEC yana da manyan buƙatu don haskakawa, diyya mai warwatsewa, daidaitaccen daidaita tsayin rami da kullewa tare, wanda zai yi tasiri sosai ga haɓaka da yawa na ramin da aka inganta resonance. A lokaci guda, amsawar matakin mara layi na plasma a wurin tsakiya na ramin shi ma ƙalubale ne. Saboda haka, a halin yanzu, wannan nau'in tushen haske bai zama babban ultraviolet mai tsanani ba.tushen haske mai jituwa mai girma.