I-laser ekhawulezayo kakhulu yesayensi ye-attosecond

I-laser ekhawulezayo kakhulukwisayensi ye-attosecond
Okwangoku, ii-attosecond pulses zifunyanwa kakhulu ngokusebenzisa i-high-order harmonic generation (HHG) eqhutywa zii-strong fields. Umongo wokuveliswa kwazo unokuqondwa njengee-electron ezifakwa kwi-ionized, zikhawuleziswe, kwaye ziphinde zihlanganiswe yi-laser electric field enamandla ukuze zikhuphe amandla, ngaloo ndlela zikhupha ii-attosecond XUV pulses.
Ke ngoko, i-attosecond output ibuthathaka kakhulu kububanzi be-pulse, amandla, ubude be-wavelength, kunye nesantya sokuphindaphinda kwe-i-laser yokuqhuba(I-laser ekhawulezayo kakhulu): ububanzi be-pulse obufutshane buluncedo ekuhlukaniseni ii-attosecond pulses, amandla aphezulu aphucula i-ionization kunye nokusebenza kakuhle, ubude be-wavelength bunyusa amandla okusika kodwa kunciphisa kakhulu ukusebenza kokuguqulwa, kwaye izinga eliphezulu lokuphindaphinda liphucula umlinganiselo wesignali-kwingxolo kodwa linqunyelwe ngamandla e-pulse enye. Izicelo ezahlukeneyo (ezifana ne-electron microscopy, i-X-ray absorption spectroscopy, ukubalwa kwe-coincidence, njl.njl.) zigxininisa ezahlukeneyo kwi-attosecond pulse index, ebeka phambili iimfuno ezahlukeneyo nezipheleleyo zokuqhuba ii-laser. Ukuphucula ukusebenza kwee-laser zokuqhuba kubalulekile ukusetyenziswa kwisayensi ye-attosecond.

Iindlela ezine eziphambili zobuchwepheshe zokuphucula ukusebenza kweeleser zokuqhuba (i-Ultra fast laser)
1. Amandla aphezulu: Yenzelwe ukoyisa ukusebenza kakuhle kokuguqulwa kwe-HHG kunye nokufumana ii-attosecond pulses eziphezulu. Utshintsho lobuchwepheshe luye lwatshintsha ukusuka kwi-chirped pulse amplification yendabuko (CPA) ukuya kwi-optical parametric amplification family, kubandakanya i-optical parametric chirped pulse amplification (OPCPA), i-dual chirped OPA (DC-OPA), i-frequency domain OPA (FOPA), kunye ne-quasi phase matching OPCPA (QPCPA). Ukudibanisa ngakumbi iindlela zokudibanisa i-coherent beam synthesis (CBC) kunye ne-pulse splitting amplification (DPA) ukoyisa imida yomzimba ye-single channel amplifier, njengeziphumo zobushushu kunye nomonakalo ongengomgca, kunye nokufezekisa isiphumo samandla se-Joule level.
2. Ububanzi be-pulse obufutshane: Yenzelwe ukuvelisa ii-pulse ze-attosecond ezizimeleyo ezinokusetyenziselwa ukuhlalutya i-electronic dynamics, ezifuna ii-pulse ezimbalwa okanye ezingaphantsi kwe-periodic driving kunye ne-stable carrier envelope phase (CEP). Ubuchwepheshe obuphambili buquka ukusebenzisa iindlela ze-nonlinear post compression ezifana ne-hollow core fiber (HCF), i-multi thin film (MPSC), kunye ne-multi-channel cavity (MPC) ukucinezela ububanzi be-pulse ukuya kubude obufutshane kakhulu. Uzinzo lwe-CEP lulinganiswa kusetyenziswa i-f-2f interferometer kwaye lufezekiswa nge-active feedback/feedforward (njenge-AOFS, i-AOPDF) okanye iindlela zokuzinzisa ezizenzekelayo ezingasebenziyo ngokusekelwe kwiinkqubo zomahluko we-frequency.
3. Ububanzi obude bomda: Yenzelwe ukutyhala amandla e-photon e-attosecond kwi-"water window" band ukuze kuthathwe imifanekiso ye-biomolecule. Iindlela ezintathu eziphambili zobuchwepheshe zezi:
I-Optical parametric amplification (OPA) kunye ne-cascade yayo: Sisisombululo esiphambili kuluhlu lwamaza obude obuyi-1-5 μ m, sisebenzisa iikristale ezifana neBiBO kunye neMgO: LN; >Iikristale ezifana neZGP kunye neLiGaS ₂ ziyafuneka kwibhendi yamaza obude obuyi-5 μ m.
Ukuveliswa kweFrequency yokwahluka (i-DFG) kunye neFrequency yokwahluka kwe-Intra Pulse (i-IPDFG): zinokubonelela ngemithombo yembewu ngozinzo lwe-CEP olungasebenziyo.
Itekhnoloji yelaser ethe ngqo, efana ne-Cr: ZnS/Se transition metal doped chalcogenide lasers, yaziwa ngokuba yi-"mid infrared titanium sapphire" kwaye ineenzuzo zesakhiwo esincinci kunye nokusebenza kakuhle okuphezulu.
4. Izinga eliphezulu lokuphindaphinda: lijolise ekuphuculeni umlinganiselo wesignali-ingxolo kunye nokusebenza kakuhle kokufunyanwa kwedatha, kunye nokujongana nemida yeziphumo zokutshaja kwendawo. Iindlela ezimbini eziphambili:
Itekhnoloji yokuphucula i-resonance cavity: ukusebenzisa i-resonant cavities echanekileyo kakhulu ukuphucula amandla aphezulu e-megahertz level repetitive frequency pulses ukuqhuba i-HHG, isetyenzisiwe kwiindawo ezifana ne-XUV frequency combs, kodwa ukuvelisa i-attosecond pulses ezizimeleyo kusazisa imingeni.
Izinga eliphezulu lokuphindaphinda kunyei-laser enamandla aphezului-direct drive, kuquka i-OPCPA, i-fiber CPA edityaniswe ne-nonlinear post compression, kunye ne-thin film oscillator, ifikelele kwi-isolated attosecond pulse generation ngesantya sokuphindaphindwa kwe-100 kHz.