24/05/22Masensa a EMCCD anali vumbulutso: onjezani chidwi chanu pochepetsa phokoso lanu lowerenga. Chabwino, pafupifupi, zowona, tinali kukulitsa siginecha kuti phokoso lanu lowerenga liwoneke ngati laling'ono.
Ndipo tidawakonda, adapeza nyumba yomwe ili ndi ma siginecha ochepa monga mamolekyu amodzi ndi ma spectroscopy ndikufalikira pakati pa opereka ma microscope pazinthu monga spinning disc, super resolution ndi kupitilira apo. Kenako tinawapha. Kapena tinatero?
Ukadaulo wa EMCCD uli ndi mbiri yake ndi ogulitsa awiri ofunikira: e2V ndi Texas Instruments. E2V, yomwe tsopano ndi Teledyne e2V, idayamba kugubuduza ndi masensa oyambilira chakumapeto kwa zaka za m'ma 1990 koma idapita patsogolo kwambiri ndi mitundu yovomerezeka kwambiri, yokhala ndi 512 x 512 yokhala ndi ma pixel 16-micron.
Sensa yoyambirira iyi, ndipo mwina yayikulu kwambiri ya EMCCD idakhudzadi ndipo theka la izi linali kukula kwa pixel. Mapikiselo a 16-micron pa microscope anasonkhanitsa kuwala kwa 6 nthawi zambiri kuposa CCD yotchuka kwambiri panthawiyo, ICX285, yomwe ili mu mndandanda wotchuka wa CoolSnap ndi Orca. Kupitilira kukula kwa pixel, zida izi zidawunikiranso kutembenuza 30% mafotoni ochulukirapo kutengera kukhudzika kuwirikiza ka 6 kukhala 7.
Chifukwa chake EMCCD inali yovuta kuwirikiza ka 7 tisanayatse ndikupeza phindu la EMCCD. Tsopano mutha kutsutsa kuti mutha kuletsa CCD, kapena mutha kugwiritsa ntchito ma optics kupanga ma pixel akulu akulu - ndi anthu ambiri sanatero!
Kupitilira izi, kuwerenga phokoso pansi pa 1 electron kunali kofunikira. Unali mfungulo, koma sunali waulere. Njira yochulukitsira idakulitsa kusatsimikizika kwa muyeso wa chizindikiro kutanthauza phokoso lowombera, mdima wakuda, ndi china chilichonse chomwe tinali nacho tisanachulutse chinawonjezeka ndi gawo la 1.4. Ndiye kodi zimenezi zinkatanthauza chiyani? Chabwino, zikutanthauza kuti EMCCD inali yovuta kwambiri koma pakuwala kochepa, ndiye kuti ndi nthawi yomwe mumayifuna molondola?
Potsutsana ndi CCD wakale, sikunali mpikisano. Ma pixel akulu, QE yambiri, EM Gain. Ndipo tonse tinali okondwa, makamaka omwe timagulitsa makamera: $40,000, chonde ...
Zinthu zokhazo zomwe tikadachita nazo zinali liwiro, gawo la sensor, komanso (osati kuti timadziwa kuti ndizotheka) kukula kwa pixel yaying'ono.
Kenako zowongolera zotumiza kunja ndi kutsata zidabwera, ndipo sizinali zosangalatsa. Zikuoneka kuti kutsatira mamolekyu amodzi ndi ma roketi omwe amatsata ndi ofanana, ndipo makampani a kamera ndi makasitomala awo amayenera kuwongolera kugulitsa kwa kamera ndi kutumiza kunja.
Kenako sCMOS idabwera, kuyambira ndikulonjeza dziko lapansi - kenako pazaka 10 zikubwerazi idatsala pang'ono kubweretsa. Ma pixel ang'onoang'ono akupeza anthu ma microns 6.5 omwe amawakonda pazolinga 60x ndipo onse okhala ndi phokoso lochepera la ma electron 1.5. Tsopano izi sizinali EMCCD ndithu, koma motsutsa 6 ma elekitironi wa kufananitsa CCD chatekinoloje nthawi zinali zodabwitsa.
Ma sCMOS oyambirira anali adakali kutsogolo. Koma mu 2016 kumbuyo kowunikira sCMOS idafika, ndikupangitsa kuti iwonekere kukhala yovuta kwambiri kumitundu yoyambirira yowunikira inali ndi ma pixel 11-micron. Ndi kuwonjezeka kwa QE ndi kukula kwa pixel, makasitomala adamva ngati ali ndi mwayi wa 3.5 x.
Pomaliza, mu 2021 phokoso lowerengera la sub-electron lidasweka pomwe makamera ena adatsika mpaka ma elekitironi 0.25 - zonse zidatha kwa EMCCD.
Kapena anali...
Chabwino, pang'ono vuto akadali pixel kukula. Apanso mutha kuchita zomwe mukufuna mwakuwona koma pamakina omwewo, pixel ya 4.6-micron imasonkhanitsa kuwala kochepera 12 x kuposa 16-micron imodzi.
Tsopano mutha kubisala, koma kumbukirani kukhala ndi CMOS yabwinobwino kumawonjezera phokoso ndi ntchito ya binning factor. Chifukwa chake anthu ambiri amasangalala ndi ma pixel awo a 6.5-micron poganiza kuti atha kubisala, koma akuchulukitsa kuwirikiza kwa ma electron atatu.
Ngakhale phokoso litha kuchepetsedwa, kukula kwa pixel, komanso bwino pankhaniyi, akadali kunyengerera pakusonkhanitsa ma siginecha enieni.
Chinthu chinanso ndikupindula ndi kusiyanitsa - kukhala ndi imvi zambiri ndikudula chizindikiro chanu chocheperako kumapereka kusiyana kwabwinoko. Mutha kukhala ndi phokoso lomwelo koma mukangowonetsa 2 imvi pa electron iliyonse yokhala ndi CMOS simupeza zambiri zoti musewere nayo mukakhala ndi ma electron 5 okha.
Pomaliza, bwanji za kutseka? Nthawi zina ndimaganiza kuti timayiwala momwe chida ichi chinali champhamvu mu EMCCD: zotsekera zapadziko lonse lapansi zimathandizadi ndipo ndizopepuka komanso zothamanga kwambiri, makamaka pamakina ovuta azinthu zambiri.
Kamera yokhayo ya sCMOS yomwe ndawonapo ikubwera ngakhale pafupi ndi 512 x 512 EMCCD sensa ndi Aries 16. Izi zimayamba ndi ma pixel a 16-micron ndipo zimapereka ma electron a 0.8 a phokoso lowerengera popanda chifukwa cha bin. Pazizindikiro za zithunzi zopitilira 5 (pa pixel 16-micron), ndikuganiza kuti ndizabwino kwambiri zomwe ndidaziwonapo komanso pafupifupi theka la mtengo.
Ndiye EMCCD yafa? Ayi, ndipo sichidzafa mpaka titapezanso chinthu chabwino chotero. Vuto ndiloti, ndiye, mavuto onse: phokoso lambiri, kukalamba, kuwongolera kunja ...
Ngati luso la EMCCD linali ndege, likanakhala Concord. Aliyense amene anawuluka anaikonda, koma mwina sanafune ndipo tsopano ndi mipando ikuluikulu ndi flatbeds - kungogona owonjezera 3 hours kudutsa Atlantic.
EMCCD, mosiyana ndi Concord, ikadali ndi moyo chifukwa anthu ena - ochepa, omwe akucheperachepera - amafunikirabe. Kapena mwina amangoganiza kuti amatero?
Kugwiritsa ntchito EMCCD, luso lojambula lokwera mtengo kwambiri komanso lovuta kwambiri silimakupangitsani kukhala apadera, kapena katswiri wazojambula - mukungochita zosiyana. Ndipo ngati simunayesere kusintha, ndiye kuti muyenera.
