Ngā whanaketanga i roto i te ultraviolet tino nuihangarau pūtake mārama
I ngā tau tata nei, kua aro nui te marea ki ngā pūtake hihi ultraviolet teitei i roto i te mara o ngā hihiri irahiko nā te kaha o te hononga, te poto o te roa o te pao me te kaha o te photon, ā, kua whakamahia i roto i ngā rangahau hihi me te whakaahua. Nā te whanaketanga o te hangarau, kuapūtake māramaKei te whanake haere ki te auau auau teitei ake, te rere o te photon teitei ake, te kaha photon teitei ake, me te whānui o te pāorooro poto ake. Ehara i te mea ka arotau noa tēnei ahunga whakamua i te taumira ine o ngā pūtake mārama ultraviolet tino nui, engari ka whakarato hoki i ngā huarahi hou mō ngā au whanaketanga hangarau ā muri ake nei. Nō reira, he mea nui te ako hohonu me te mārama ki te pūtake mārama ultraviolet tino nui o te auau auau teitei hei matatau me te whakamahi i ngā hangarau hou.
Mō ngā inenga mātai irahiko i runga i ngā tauine wā femtosecond me attosecond, he maha ngā wā kāore e ranea te maha o ngā huihuinga i inehia i roto i te hihi kotahi, ā, kāore e ranea ngā pūtake mārama auau iti hei whiwhi tatauranga pono. I taua wā anō, ka whakaitihia e te pūtake mārama he iti te rerenga photon te ōwehenga tohu-ki-haruru o te whakaahua moroiti i te wā whakaaturanga iti. Mā te tūhuratanga me ngā whakamātautau tonu, he maha ngā whakapainga kua mahia e ngā kairangahau i roto i te arotautanga hua me te hoahoa tuku o te mārama ultraviolet tino auau auau teitei. Kua whakamahia te hangarau tātari spectral matatau i honoa ki te pūtake mārama ultraviolet tino auau auau teitei hei whakatutuki i te ine tika o te hanganga rauemi me te tukanga hihiri hiko.
Ko ngā tono o ngā pūtake mārama ultraviolet tino nui, pērā i ngā inenga o te angular resolved electron spectroscopy (ARPES), me whai hihi o te mārama ultraviolet tino nui hei whakamārama i te tauira. Ka whakaohokia ngā irahiko i runga i te mata o te tauira ki te āhua tonu e te mārama ultraviolet tino nui, ā, kei roto i te pūngao nekeneke me te koki tukunga o ngā irahiko whakaahua ngā mōhiohio hanganga roopu o te tauira. Ka whiwhi te tātari irahiko me te mahi koki taumira i ngā irahiko whakaahua kua whakapūatatia, ā, ka whiwhi i te hanganga roopu tata ki te roopu valence o te tauira. Mō te pūtake mārama ultraviolet tino nui, he auau iti te auau tāruarua, nā te mea he nui ngā photon kei roto i tana pā kotahi, ka whakaohokia e ia he maha ngā photon i runga i te mata tauira i roto i te wā poto, ā, ka puta he whānui nui o te tohatoha o te pūngao nekeneke o te irahiko whakaahua mā te taunekeneke Coulomb, e kiia nei ko te pānga utu wāhi. Hei whakaiti i te awe o te pānga utu wāhi, me whakaiti ngā irahiko whakaahua kei roto i ia pā me te pupuri tonu i te rere photon pumau, nō reira me akiaki terēserime te auau auau teitei hei whakaputa i te pūtake mārama ultraviolet tino kaha me te auau auau teitei.
Mā te hangarau kōhao whakarei ake i te haruru ka taea te whakaputa i ngā haruru oro teitei i te auau auau MHz.
Hei whiwhi i tētahi pūtake mārama ultraviolet tino kaha me te tere whakahokinga tae atu ki te 60 MHz, i whakahaerehia e te tīma Jones i te Whare Wānanga o British Columbia i te United Kingdom te whakaputanga harmonic ota teitei i roto i te kōhao whakarei ake i te resonance femtosecond (fsEC) hei whakatutuki i tētahi pūtake mārama ultraviolet tino kaha, ā, i whakamahia ki ngā whakamātautau irahiko whakatau koki wā-whakatau (Tr-ARPES). Ka taea e te pūtake mārama te tuku i te rerenga photon neke atu i te 1011 ngā tau photon ia hekona me te harmonic kotahi i te tere whakahokinga o te 60 MHz i roto i te awhe pūngao o te 8 ki te 40 eV. I whakamahia e rātou he pūnaha laser muka kua tāpirihia ki te ytterbium hei pūtake purapura mō te fsEC, ā, i whakahaerehia ngā āhuatanga pāorooro mā te hoahoa pūnaha laser kua whakaritea hei whakaiti i te haruru auau taupatupatu kawe (fCEO) me te pupuri i ngā āhuatanga pēhanga pāorooro pai i te mutunga o te mekameka whakakaha. Hei whakatutuki i te whakarei ake i te auorotanga pumau i roto i te fsEC, e toru ngā koropiko whakahaere servo e whakamahia ana hei whakahaere urupare, ka hua ake he pumau kaha i ngā nekehanga herekore e rua: ko te wā haerenga hoki-mai o te huringa pātere i roto i te fsEC e ōrite ana ki te wā pātere taiaho, me te nekehanga ā-wāhanga o te kaikawe mara hiko e pā ana ki te kōpaki pātere (arā, te wāhanga kōpaki kaikawe, ϕCEO).
Mā te whakamahi i te hau krypton hei hau mahi, i tutuki i te tīma rangahau te whakaputanga o ngā harmonika teitei ake i roto i te fsEC. I whakahaerehia e rātou ngā inenga Tr-ARPES o te karāpeti, ā, i kitea te whakamahana tere me te whakakotahitanga puhoi o ngā taupori irahiko kāore i te whakaohohia e te wera, me te hihiri o ngā āhua whakaoho tika kāore i te wera tata ki te taumata Fermi i runga ake i te 0.6 eV. He taputapu nui tēnei pūtake mārama mō te ako i te hanganga hiko o ngā rauemi uaua. Heoi, he tino teitei ngā whakaritenga mō te whakaata, te utu marara, te whakatikatika pai o te roa o te kōhao me te raka tukutahitanga o te whakaputanga o ngā harmonika teitei ake i roto i te fsEC, ka pā nui ki te maha whakarei ake o te kōhao whakarei ake i te oro. I taua wā anō, he wero anō hoki te urupare ā-wāhanga kore-raina o te plasma i te pūwāhi arotahi o te kōhao. Nō reira, i tēnei wā, kāore anō tēnei momo pūtake mārama kia waiho hei ultraviolet tino nui.pūtake māramatanga harmonic teitei.
Wā tuku: 29 Paenga-whāwhā 2024