Khatelo-pele ea mahlaseli a kotsi a ultraviolettheknoloji ea mohloli oa leseli
Lilemong tsa morao tjena, mehloli e feteletseng ea ultraviolet e phahameng ea harmonic e hohetse tlhokomelo e pharaletseng tšimong ea matla a elektronike ka lebaka la momahano oa bona o matla, nako e khutšoanyane ea nako le matla a phahameng a photon, 'me e sebelisitsoe lithutong tse sa tšoaneng tsa spectral le litšoantšo.Ka tsoelo-pele ea theknoloji, senamohloli o khanyange ntse e tsoela pele ho ea ho makhetlo a holimo a pheta-phetoang, phallo e phahameng ea photon, matla a phahameng a photon le bophara bo khutšoanyane ba ho otla ha pelo.Khatelo-pele ena ha e ntlafatse tharollo ea tekanyo ea mehloli e feteletseng ea mahlaseli a ultraviolet, empa hape e fana ka menyetla e mecha bakeng sa mekhoa ea nakong e tlang ea tsoelo-pele ea theknoloji.Ka hona, boithuto bo tebileng le kutloisiso ea mohloli oa khanya ea ultraviolet e pheta-phetoang khafetsa ke oa bohlokoa haholo bakeng sa ho tseba le ho sebelisa theknoloji e tsoetseng pele.
Bakeng sa litekanyo tsa electron spectroscopy sekala sa nako ea femtosecond le attosecond, palo ea liketsahalo tse lekantsoeng ka lebaleng le le leng hangata ha e lekane, e leng ho etsang hore mehloli ea leseli e tlaase e sa lekana ho fumana lipalo-palo tse tšepahalang.Ka nako e ts'oanang, mohloli o khanyang o nang le photon flux e tlaase e tla fokotsa tekanyo ea pontšo-ho-lerata ea litšoantšo tse nyenyane haholo nakong ea nako e lekanyelitsoeng ea ho pepeseha.Ka lipatlisiso le liteko tse tsoelang pele, bafuputsi ba entse lintlafatso tse ngata molemong oa ntlafatso ea lihlahisoa le moralo oa phetisetso ea khanya e phahameng ea khafetsa ea khanya ea ultraviolet.Theknoloji e tsoetseng pele ea tlhahlobo ea spectral e kopantsoeng le maqhubu a phahameng a pheta-pheta mohloli oa khanya ea ultraviolet e feteletseng e 'nile ea sebelisoa ho finyella tekanyo e phahameng e nepahetseng ea sebopeho sa thepa le ts'ebetso ea matla ea elektronike.
Ts'ebeliso ea mehloli e feteletseng ea leseli la ultraviolet, joalo ka litekanyo tsa elektrone tsa spectroscopy (ARPES), li hloka khanya e matla ea ultraviolet ho bonesa sampole.Lielektrone tse holim'a sampole li thabetse boemo bo tsoelang pele ka khanya e feteletseng ea ultraviolet, 'me matla a kinetic le emission Angle ea li-photoelectrons li na le tlhaiso-leseling ea sebopeho sa sehlopha sa sampole.Elektrone analyzer e nang le Angle resolution function e amohela li-photoelectrons tse mahlaseli 'me e fumana sebopeho sa sehlopha se haufi le sehlopha sa valence sa sampole.Bakeng sa mohloli o fokolang oa ho pheta-pheta o feteletseng oa leseli la ultraviolet, hobane phallo ea eona e le 'ngoe e na le palo e kholo ea photons, e tla thabisa palo e kholo ea li-photoelectrons sebakeng sa mohlala ka nako e khutšoanyane,' me tšebelisano ea Coulomb e tla tlisa keketseho e tebileng ea kabo. matla a photoelectron kinetic, a bitsoang "space charge effect".E le ho fokotsa tšusumetso ea phello ea tefiso ea sebaka, hoa hlokahala ho fokotsa li-photoelectrons tse ka har'a sekhahla se seng le se seng ha u ntse u boloka photon flux e sa khaotseng, kahoo hoa hlokahala ho khannalaserka makhetlo a mangata a ho pheta-pheta ho hlahisa mohloli o feteletseng oa leseli la ultraviolet le maqhubu a phahameng a ho pheta-pheta.
Theknoloji e ntlafalitsoeng ea "resonance cavity" e hlokomela tlhahiso ea li-harmonics tse phahameng ka makhetlo a MHz a pheta-phetoang
E le ho fumana mohloli o feteletseng oa khanya ea ultraviolet ka lebelo la ho pheta-pheta ho fihla ho 60 MHz, sehlopha sa Jones Univesithing ea British Columbia United Kingdom se ile sa etsa tlhahiso e phahameng ea harmonic ka femtosecond resonance enhancement cavity (fsEC) ho finyella katleho e sebetsang. mohloli o feteletseng oa lebone la ultraviolet mme oa e sebelisa litekong tse rarollotsoeng ka nako tse rarollotsoeng tsa elektrone spectroscopy (Tr-ARPES).Mohloli oa leseli o khona ho fana ka photon flux ea linomoro tse fetang 1011 tsa photon motsotsoana ka har'a harmonic e le 'ngoe ka lebelo la ho pheta-pheta la 60 MHz sebakeng sa matla a 8 ho ea ho 40 eV.Ba sebelisitse ytterbium-doped fiber laser system e le mohloli oa peo bakeng sa fsEC, 'me ba laola pulse ka mokhoa o hlophisitsoeng oa laser system ho fokotsa lerata la carrier envelope offset frequency (fCEO) le ho boloka litšobotsi tse ntle tsa khatello ea pulse qetellong ea ketane ea amplifier.Ho fihlela ntlafatso e tsitsitseng ea resonance ka har'a fsEC, ba sebelisa li-loops tse tharo tsa taolo ea servo bakeng sa taolo ea maikutlo, e bakang botsitso bo sebetsang ka likhato tse peli tsa tokoloho: nako ea ho ea le ho khutla ha pulse cycling ka har'a fsEC e ts'oana le nako ea laser pulse, le phase shift. ea mokhanni oa tšimo ea motlakase mabapi le enfelopo ea pulse (ke hore, mohato oa enfelopo ea mojari, ϕCEO).
Ka ho sebelisa khase ea krypton e le khase e sebetsang, sehlopha sa lipatlisiso se fihletse tlhahiso ea li-harmonics tsa maemo a holimo ho fsEC.Ba ile ba etsa litekanyo tsa Tr-ARPES tsa graphite 'me ba hlokomela mocheso o potlakileng le ho kopanya butle butle ha batho ba sa thabiseng ba elektronike, hammoho le matla a linaha tse sa thabiseng ka ho toba haufi le boemo ba Fermi ka holimo ho 0.6 eV.Mohloli ona oa leseli o fana ka sesebelisoa sa bohlokoa sa ho ithuta sebopeho sa elektronike sa thepa e rarahaneng.Leha ho le joalo, tlhahiso ea li-harmonics tse phahameng ho fsEC e na le litlhoko tse phahameng haholo bakeng sa ho bonahatsa maikutlo, puseletso ea ho hasana, ho lokisoa hantle ha bolelele ba cavity le ho notlela ka tsela e lumellanang, e leng ho tla ama haholo ntlafatso ea palo e eketsehileng ea "resonance-enhanced cavity".Ka nako e ts'oanang, karabelo ea karolo e sa lekanyetsoang ea plasma sebakeng sa mantlha sa cavity le eona ke phephetso.Ka hona, hona joale, mofuta ona oa mohloli oa leseli ha o e-s'o fetohe mahlaseli a kotsi a feteletsengmohloli o phahameng oa leseli oa harmonic.
Nako ea poso: Apr-29-2024