24/05/22Izinzwa ze-EMCCD beziyisambulo: khulisa ukuzwela kwakho ngokunciphisa umsindo wakho wokufunda. Hhayi-ke, cishe, ngokweqiniso besikhulisa isiginali ukuze senze umsindo owufundayo ubukeke sengathi mncane.
Futhi sasibathanda, bathola ikhaya eliseduze elinomsebenzi wesignali ephansi njenge-molecule eyodwa kanye ne-spectroscopy base besakazeka phakathi kwabahlinzeki besistimu ye-microscope yezinto ezifana ne-spinning disc, ukulungiswa okuphezulu nokunye. Sabe sesibabulala. Noma thina?
Ubuchwepheshe be-EMCCD bunomlando wabo nabahlinzeki ababili ababalulekile: i-e2V ne-Texas Instruments. I-E2V, manje eyi-Teledyne e2V, iqale lokhu kugoqa ngezinzwa zakuqala ngasekupheleni kwawo-1990 kodwa yenza igxathu langempela ngokuhlukile okwamukeleka kakhulu, inohlu lwama-512 x 512 namaphikseli angu-16-micron.
Le nzwa yokuqala, futhi cishe ebusa kakhulu ye-EMCCD ibe nomthelela wangempela futhi ingxenye yalokhu bekungusayizi wamaphikseli ngempela. Amaphikseli angu-16-micron kusibonakhulu aqoqwe ukukhanya okuphindwe ka-6 kune-CCD edume kakhulu yangaleso sikhathi, i-ICX285, efakwe ochungechungeni oludumile lwe-CoolSnap ne-Orca. Ngalé kosayizi wephikseli, lawa madivayisi abuye akhanyisiwe aguqula ama-photon angu-30% ngaphezulu athatha ukuzwela okukhulu ngokuphindwe ka-6 kuya ku-7.
Ngakho-ke ngempumelelo i-EMCCD yayizwela izikhathi eziyisi-7 ngaphambi kokuthi siyivule futhi sithole umthelela wenzuzo ye-EMCCD. Manje ungaphikisa ukuthi ungabopha i-CCD, noma ungasebenzisa okokubona ukuze udale osayizi bamaphikseli abakhudlwana - abantu abaningi abawenzanga!
Ngaphandle kwalokhu, ukuthola umsindo ofundwayo ngaphansi kwe-electron engu-1 kwakubalulekile. Bekuyisihluthulelo, kepha bekungamahhala. Inqubo yokuphindaphinda ikhulise ukungaqiniseki kwesilinganiso sesignali okusho umsindo odubulayo, igagasi elimnyama, nanoma yini enye esasinayo ngaphambi kokuphindaphinda yanyuswa ngesici esingu-1.4. Ngakho, kwakusho ukuthini lokho? Hhayi-ke, kwakusho ukuthi i-EMCCD yayizwela kakhulu kodwa ekukhanyeni okuphansi kuphela, kuhle-ke lokho kuwuhlobo lokuthi uyidinga nini?
Ngokumelene ne-CCD yakudala, bekungewona umqhudelwano. Amaphikseli amakhulu, i-QE eningi, i-EM Gain. Futhi sonke sasijabule, ikakhulukazi thina esithengisa amakhamera: $40,000, sicela ...
Okuwukuphela kwezinto ebesingazenza kakhulu ngesivinini, indawo yezinzwa, kanye (hhayi ukuthi besazi ukuthi kungenzeka) usayizi wamaphikseli amancane.
Kwabe sekufika izilawuli zokuthekelisa nokuthobela, futhi lokho akuzange kube mnandi. Kuvela ukuthi ukulandelela ama-molecule angawodwa kanye namarokhethi okulandelela kuyafana, futhi izinkampani zamakhamera namakhasimende azo bekufanele zilawule ukuthengiswa kwamakhamera nokuthunyelwa kwamanye amazwe.
Kwabe sekufika i-sCMOS, iqala ngokuthembisa umhlaba - kwase kuthi eminyakeni eyi-10 elandelayo yacishe yayiletha. Amaphikseli amancane athola abantu ama-microns angu-6.5 ababewathanda ngezinjongo ezingu-60x futhi wonke anomsindo ophansi wokufunda cishe wama-electron angu-1.5. Manje lokhu kwakungeyona i-EMCCD, kodwa ngokumelene nama-electron angu-6 wobuchwepheshe be-CCD bokuqhathanisa ngaleso sikhathi kwakumangalisa.
Ama-sCMOS okuqala ayesakhanyisiwe ngaphambili. Kodwa ngo-2016 kwafika i-sCMOS ekhanyiselwe emuva, futhi ukuyenza ibonakale izwela kakhulu ezinguqulweni ezikhanyiswe ngaphambili yayinamaphikseli angu-11-micron. Ngokukhula kwe-QE nosayizi wamaphikseli, amakhasimende azizwe sengathi anenzuzo engu-3.5 x.
Ekugcineni, ngo-2021 umsindo wokufundwa kwe-electron engaphansi wephulwa amanye amakhamera ehle afinyelela kuma-electron angu-0.25 - kwase kuphelile nge-EMCCD.
Noma ngabe...
Nokho, inkinga encane isengusayizi wephikseli. Nalapha ungenza okufunayo ngokubonayo kodwa ohlelweni olufanayo, i-pixel engu-4.6-micron iqoqa ukukhanya okungaphansi okungu-12 x kune-16-micron eyodwa.
Manje usungakwazi ukufaka, kodwa khumbula ukubopha nge-CMOS evamile kwandisa umsindo ngomsebenzi we-binning factor. Ngakho-ke abantu abaningi bajabule ngamaphikseli abo angu-6.5-micron becabanga ukuthi bangakwazi ukuhlanganisa indlela yabo yokuzwela, kodwa baphinda kabili umsindo wabo wokufunda kuma-electron angu-3.
Ngisho noma umsindo ungancishiswa, usayizi we-pixel, futhi ugcwele kahle ngaleyo ndaba, kusese ukuthopha ekuqoqweni kwesignali yangempela.
Enye into ukuzuza kanye nokugqama - ukuba nezimpunga eziningi nokusika isiginali yakho ibe kuncane kunikeza umehluko ongcono. Ungaba nomsindo ofanayo kodwa uma ubonisa izimpunga ezi-2 kuphela ku-electron ngayinye ene-CMOS awutholi okuningi ongadlala ngakho uma unama-electron angu-5 kuphela esignali.
Ekugcineni, kuthiwani nge-shuttering? Kwesinye isikhathi ngicabanga ukuthi siyakhohlwa ukuthi leli thuluzi belinamandla kangakanani ku-EMCCD: izivalo zomhlaba wonke ziyasiza ngempela futhi zilula kakhulu futhi zisebenza kahle ngesivinini, ikakhulukazi ezinhlelweni eziyinkimbinkimbi zezingxenye eziningi.
Okuwukuphela kwekhamera ye-sCMOS engiyibonile isondela ngisho eduze kwenzwa engu-512 x 512 EMCCD yi-Aries 16. Lokhu kuqala ngamaphikseli angu-16-micron futhi iletha ama-electron angu-0.8 omsindo ofundwayo ngaphandle kwesidingo sokuwafaka. Ngezimpawu zama-photon angaphezu kuka-5 (iphikseli ngayinye engu-16-micron), ngicabanga ukuthi iyona engcono kakhulu engake ngayibona futhi cishe ingxenye yentengo.
Ngakho ingabe i-EMCCD ifile? Cha, futhi ngeke ngempela ife kuze kube yilapho sithola okuthile okuhle futhi. Inkinga, kahle, zonke izinkinga: umsindo owedlulele, ukuguga, izilawuli zokuthekelisa...
Ukube ubuchwepheshe be-EMCCD bekuyindiza, bekungaba yi-Concord. Wonke umuntu owayeyindiza wayeyithanda, kodwa cishe babengayidingi futhi manje enezihlalo ezinkulu nemibhede eyisicaba – vele ulale lawo mahora angu-3 engeziwe ngaphesheya kwe-Atlantic.
I-EMCCD, ngokungafani ne-Concord, isaphila ngoba abanye abantu - inombolo encane, eyehla njalo - basayidinga. Noma mhlawumbe bacabanga ukuthi bayakwenza?
Ukusebenzisa i-EMCCD, ubuchwepheshe bezithombe obubiza kakhulu nobuyinkimbinkimbi obusetshenziswa kabanzi abukwenzi ukhethekile, noma uchwepheshe wezithombe - wenza okuthile okuhlukile. Futhi uma ungazange uzame ukushintsha, khona-ke cishe kufanele.
