25/08/01Inzwa ye-Electron-Multiplying CCD iwukuvela kwenzwa ye-CCD ukuvumela ukusebenza kokukhanya okuphansi. Ngokuvamile zenzelwe amasiginali wama-photoelectrons angamakhulu ambalwa, kuze kufike ezingeni ngalinye lokubala ama-photon.
Lesi sihloko sichaza ukuthi ziyini izinzwa ze-EMCCD, ukuthi zisebenza kanjani, izinzuzo zazo kanye nokubi, nokuthi kungani zibhekwa njengenguquko elandelayo yobuchwepheshe be-CCD ekufanekisweni kokukhanya okuphansi.
Iyini inzwa ye-EMCCD?
Inzwa ye-Electron-Multiplying Charge-Coupled Device (EMCCD) iwuhlobo olukhethekile lwenzwa ye-CCD ekhulisa amasignali abuthakathaka ngaphambi kokuba afundwe, okuvumela ukuzwela okuphezulu kakhulu ezindaweni ezinokukhanya okuphansi.
Ekuqaleni yakhelwe izinhlelo zokusebenza ezifana ne-astronomy kanye ne-microscope ethuthukisiwe, ama-EMCCD angakwazi ukubona ama-photon eyodwa, umsebenzi izinzwa ze-CCD zendabuko ezilwa nawo. Leli khono lokubona ama-photon angawodwana lenza ama-EMCCD abaluleke kakhulu ezinkambini ezidinga ukuthwebula izithombe okunembile ngaphansi kwamazinga okukhanya aphansi kakhulu.
Zisebenza Kanjani Izinzwa ze-EMCCD?
Kuze kube sezingeni lokufunda, izinzwa ze-EMCCD zisebenza ngezimiso ezifanayo nezinzwa ze-CCD. Kodwa-ke, ngaphambi kokulinganisa nge-ADC, izindleko ezitholiwe ziphindaphindwa ngenqubo ebizwa ngokuthi i- impactionization, 'kwirejista yokuphindaphinda ama-electron'. Ngaphezulu kochungechunge lwezinyathelo ezingamakhulu ambalwa, amashaji asuka kuphikseli ahanjiswa ngochungechunge lwamaphikseli agqunyiwe ku-voltage ephezulu. I-electron ngayinye esinyathelweni ngasinye inethuba lokuletha ama-electron engeziwe. Ngakho-ke isignali iphindaphindeka ngokuqhubekayo.
Umphumela wokugcina we-EMCCD elinganiswe kahle yikhono lokukhetha inani elinembile lokuphindaphinda okumaphakathi, ngokuvamile okungaba ngu-300 kuya ku-400 ngomsebenzi wokukhanya okuphansi. Lokhu kwenza amasiginali atholiwe aphindaphindwe phezulu kakhulu kunomsindo ofundiwe wekhamera, empeleni kunciphisa umsindo ofundwayo wekhamera. Ngeshwa, isimo se-stochastic sale nqubo yokuphindaphinda sisho ukuthi ipikseli ngayinye iphindaphindwa ngenani elihlukile, elethula isici somsindo esengeziwe, esinciphisa isilinganiso se-EMCCD's signal-to-noise (SNR).
Nakhu ukuhlukaniswa kokuthi izinzwa ze-EMCCD zisebenza kanjani. Kuze kube Isinyathelo sesi-6, inqubo ifana ngokuphumelelayo naleyo yezinzwa ze-CCD.
Umfanekiso: Inqubo yokufunda yenzwa ye-EMCCD
Ekupheleni kokuchayeka kwazo, izinzwa ze-EMCCD ziqale zihambise ngokushesha izindleko eziqoqiwe kuhlu lwamaphikseli amboziwe anobukhulu obufanayo nohlu oluzwelayo olukhanyayo (ukudluliswa kozimele). Bese, umugqa owodwa ngesikhathi, izindleko zihanjiswa kurejista yokufunda. Ikholomu eyodwa ngesikhathi, izindleko ezingaphakathi kwerejista yokufunda zidluliselwa kurejista yokuphindaphinda. Esigabeni ngasinye sale rejista (kufika ezigabeni eziyi-1000 kumakhamera we-EMCCD wangempela), yonke i-electron inethuba elincane lokukhulula i-electron eyengeziwe, iphindaphinda isignali ngokuqhubekayo. Ekugcineni, isignali ephindaphindwe iyafundwa.
1. Ukushaja Ukusula: Ukuze uqale ukutholwa, inkokhiso isuswa ngesikhathi esisodwa kuyo yonke inzwa (i-global shutter).
2. Ukuqoqwa Kwezindleko: Imali inqwabelana ngesikhathi sokuchayeka.
3. Shaja Isitoreji: Ngemva kokuchayeka, izindleko eziqoqiwe ziyiswa endaweni efihliwe yenzwa, lapho zingalinda khona ukufundwa ngaphandle kokuthi amaphothoni amasha atholiwe ebaliwe. Lena inqubo 'Yokudlulisa Uhlaka'.
4. Ukuchayeka Kozimele Okulandelayo: Ngamanani atholiwe agcinwe kumaphikseli afihliwe, amaphikseli asebenzayo angaqala ukuvezwa kozimele olandelayo (imodi yokugqagqana).
5. Inqubo yokufunda: Umugqa owodwa ngesikhathi, izindleko zomugqa ngamunye wohlaka oluqediwe ziyiswa 'kurejista yokufunda'.
6. Ikholomu eyodwa ngesikhathi, amashaji asuka kuphikseli ngayinye avaleleka endaweni yokufunda.
7. Electron Ukuphindaphindeka: Okulandelayo, wonke amashaji e-electron asuka ku-pixel afaka irejista yama-electron wokuphindaphindeka, futhi aqhubeke nesinyathelo ngesinyathelo, aphindaphindeke ngenombolo ngokushesha esinyathelweni ngasinye.
8. Funda ngokuphimisela: Isignali ephindaphindekile ifundwa yi-ADC, futhi inqubo iyaphindwa kuze kube yilapho lonke ifremu ifundwa.
Izinzuzo Nezingozi Zezinzwa ze-EMCCD
Izinzuzo ze-EMCCD Sensors
| Inzuzo | Incazelo |
| Ukubala kwezithombe | Ithola ama-photoelectrons angawodwana anomsindo wokufunda ophansi kakhulu (<0.2e⁻), ovumela ukuzwela kwesithombe esisodwa. |
| Ukuzwela Kokukhanya Okuphansi | Ingcono kakhulu kunama-CCD endabuko, kwesinye isikhathi idlula ngisho namakhamera we-sCMOS asezingeni eliphezulu emazingeni okukhanya aphansi kakhulu. |
| Okumnyama Okuphansi Kwamanje | Ukupholisa okujulile kunciphisa umsindo oshisayo, kunika amandla izithombe ezihlanzekile ngesikhathi sokuchayeka isikhathi eside. |
| 'Half-Global' Shutter | Ukudluliswa kozimele kuvumela ukuchayeka okuseduze komhlaba wonke ngokushintsha kokushaja okusheshayo (~1 microsecond). |
● Ukubala kwezithombe: Ngokuphindaphinda kwama-electron aphezulu ngokwanele, umsindo ofundwayo ungaqedwa ngokoqobo (<0.2e-). Lokhu, eceleni kwenani lenzuzo ephezulu kanye nokusebenza kahle kwe-quantum, kusho ukuthi ukuhlukanisa ama-photoelectrons ngamanye kungenzeka.
● Ukuzwela Kokukhanya Okuphansi Kakhulu: Uma kuqhathaniswa nama-CCDs, ukusebenza kokukhanya okuphansi kwe-EMCCDs kungcono kakhulu. Kungase kube khona ezinye izinhlelo zokusebenza lapho i-EMCCD inikeza amandla okuthola angcono kanye nokugqama ngisho kune-sCMOS yesiphetho esiphezulu kumazinga okukhanya aphansi kakhulu.
● Okumnyama Okuphansi Kwamanje: Njengama-CCDs, ama-EMCCD avamise ukuba aphole ngokujulile futhi akwazi ukuletha amanani aphansi kakhulu amnyama.
● 'I-Half Global' Shutter: Inqubo yokudlulisa uzimele ukuqala nokuqeda ukuchayeka ayikona ngesikhathi esisodwa, kodwa ngokuvamile ithatha i-oda le-microsecond engu-1.
Ububi bezinzwa ze-EMCCD
| Ububi | Incazelo |
| Isivinini Esinomkhawulo | Izilinganiso zozimele eziphezulu (~30 fps ku-1 MP) zihamba kancane kakhulu kunezinye izindlela zesimanje ze-CMOS. |
| Umsindo Wokukhuliswa | Imvelo engahleliwe yokuphindaphindeka kwe-electron yethula umsindo owedlulele, kunciphisa i-SNR. |
| Ukushaja Okubangelwa Iwashi (CIC) | Ukunyakaza kokushaja okusheshayo kungethula izimpawu ezingamanga ezikhuliswayo. |
| Ububanzi Obuncishisiwe | Ukuzuza okuphezulu kunciphisa isignali ephezulu inzwa engakwazi ukuyiphatha ngaphambi kokugcwala. |
| Usayizi wePixel Omkhulu | Osayizi bamaphikseli abavamile (13–16 μm) bangase bangahambisani nezidingo eziningi zesistimu yokubona. |
| Imfuneko Yokupholisa Kakhulu | Ukupholisa okujulile okuzinzile kuyadingeka ukuze kuzuzwe ukuphindaphinda okungaguquki nomsindo ophansi. |
| Izidingo Zokulinganisa | Ukuzuza kwe-EM kuyehla ngokuhamba kwesikhathi (ukubola kokuphindaphinda), kudinga ukulinganisa okuvamile. |
| Ukungazinzi kokuvezwa okufushane | Ukuchayeka okufushane kakhulu kungabangela ukukhuliswa kwesignali okungalindelekile nomsindo. |
| Izindleko Eziphakeme | Ukukhiqiza okuyinkimbinkimbi kanye nokupholisa okujulile kwenza lezi zinzwa zibize kakhulu kune-sCMOS. |
| Ukuphila Okulinganiselwe | Irejista yokuphindaphinda kwama-electron iyaguga, ngokuvamile ihlala iminyaka emi-5-10. |
| Thumela Izinselele | Kungaphansi kwemithetho eqinile ngenxa yezicelo zezempi ezingase zibe khona. |
● Isivinini Esinomkhawulo: Ama-EMCCD asheshayo ahlinzeka cishe ngama-fps angu-30 ku-MP engu-1, afana nama-CCDs, ama-oda wobukhulu ahamba kancane kunamakhamera e-CMOS.
● Isingeniso Somsindo: 'Isici somsindo oweqile' esibangelwa ukuphindaphindeka kwe-electron okungahleliwe, uma kuqhathaniswa nekhamera ye-sCMOS yomsindo ophansi enokusebenza kahle kwe-quantum, inganikeza ama-EMCCD umsindo ophakeme kakhulu kuye ngamaleveli esignali. I-SNR ye-high-end sCMOS ngokuvamile ingcono kumasiginali azungeze i-3e-, ngisho nangaphezulu kumasiginali aphezulu.
● Ukushaja Okubangelwa Iwashi (CIC): Ngaphandle kwalapho kulawulwa ngokucophelela, ukunyakaza kwezindleko kuyo yonke inzwa kungethula ama-electron engeziwe abe amaphikseli. Lo msindo ube usuphindaphindwa yirejista yokuphindaphinda kwama-electron. Isivinini sokunyakaza kokushaja okuphezulu (izilinganiso zewashi) ziholela kumazinga aphezulu ozimele, kodwa i-CIC eyengeziwe.
● Ububanzi obuncishisiwe obunamandla: Amanani aphezulu kakhulu okuphindaphinda ama-electron adingekayo ukuze kunqobe umsindo ofundekayo we-EMCCD aholela ebangeni eliguquguqukayo elinciphe kakhulu.
● Usayizi Wephikseli Enkulu: Usayizi omncane wephikseli ojwayelekile wamakhamera we-EMCCD ngu-10 μm, kodwa u-13 noma 16 μm uvame kakhulu. Lokhu kukhulu kakhulu ukufana nezidingo eziningi zokulungiswa kwesistimu yokubona.
● Izidingo Zokulinganisa: Inqubo yokuphindaphinda ama-electron igugisa irejista ye-EM ngokusetshenziswa, inciphisa amandla ayo okuphindaphinda ngenqubo ebizwa ngokuthi 'i-electron multiplication decay'. Lokhu kusho ukuthi inzuzo yekhamera ihlala ishintsha, futhi ikhamera idinga ukulinganisa okuvamile ukuze yenze noma yikuphi ukuthwebula kwezithombe.
● Ukuchayeka Okungahambisani Ngezikhathi Ezifushane: Uma usebenzisa izikhathi zokuchayeka ezimfushane kakhulu, amakhamera e-EMCCD angase akhiqize imiphumela engahambisani ngenxa yokuthi isignali ebuthakathaka iqoqwa umsindo, futhi inqubo yokukhulisa ingenisa ukuguquguquka kwezibalo.
● Imfuneko Yokupholisa Kakhulu: Inqubo yokuphindaphinda ama-electron ithonywa kakhulu izinga lokushisa. Ukupholisa inzwa kukhulisa ukuphindaphindeka kwe-electron etholakalayo. Ngakho-ke ukupholisa kwenzwa ejulile ngenkathi kugcinwa ukuzinza kwezinga lokushisa ngakho-ke kubalulekile ezilinganisweni eziphindaphindekayo ze-EMCCD.
● Izindleko eziphezulu: Ubunzima bokwenziwa kwalezi zinzwa ezinezingxenye eziningi, kuhlanganiswe nokupholisa okujulile, kuholela ezintengo ngokuvamile eziphakeme kunamakhamera ezinzwa wekhwalithi ephezulu we-sCMOS.
● Ukuphila Okulinganiselwe: Ukubola kokuphindaphindeka kwe-electron kubeka umkhawulo ekuphileni kwalezi zinzwa ezibizayo ngokuvamile iminyaka engu-5-10, kuye ngezinga lokusetshenziswa.
● Thumela Izinselele: Ukungenisa nokuthekelisa kwezinzwa ze-EMCCD kuvame ukuba yinselelo ngenxa yokusetshenziswa kwazo ezinhlelweni zempi.
Kungani i-EMCCD Ilandela I-CCD
| Isici | I-CCD | I-EMCCD |
| Ukuzwela | Phezulu | Ukukhanya okuphezulu kakhulu (ikakhulukazi ukukhanya okuphansi) |
| Readout Noise | Kuphakathi | Kuphansi kakhulu (ngenxa yenzuzo) |
| I-Dynamic Range | Phezulu | Okumaphakathi (kukhawulelwe ngenzuzo) |
| Izindleko | Phansi | Phezulu |
| Ukupholisa | Ongakukhetha | Ngokuvamile kuyadingeka ukuze usebenze kahle |
| Sebenzisa Amacala | Isithombe esijwayelekile | Ukukhanya okuphansi, ukutholwa kwesithombe esisodwa |
Izinzwa ze-EMCCD zakha kubuchwepheshe be-CCD bendabuko ngokuhlanganisa isinyathelo sokuphindaphinda ama-electron. Lokhu kuthuthukisa ikhono lokukhulisa amasiginali abuthakathaka futhi kuncishiswe umsindo, okwenza ama-EMCCD abe yinketho ekhethwayo yezinhlelo zokusebenza zokuthwebula izithombe zokukhanya okuphansi kakhulu lapho izinzwa ze-CCD zisilela khona.
Izicelo Ezibalulekile Zezinzwa ze-EMCCD
Izinzwa ze-EMCCD zivame ukusetshenziswa emikhakheni yesayensi neyezimboni edinga ukuzwela okuphezulu kanye nekhono lokubona amasiginali afiphele:
● I-Life Science imaging: Kuzinhlelo zokusebenza ezifana ne-single-molecule fluorescence microscopy kanye nesamba se-internal reflection fluorescence (TIRF) microscopy.
● Isayensi yezinkanyezi: Isetshenziselwa ukuthwebula ukukhanya okufiphele okuvela ezinkanyezini ezikude, imithala, nocwaningo lwe-exoplanet.
● I-Quantum Optics: Okokufakwa kwe-photon kanye nokuhlolwa kolwazi lwe-quantum.
● I-Forensics kanye Nezokuphepha: Kuqashwe ekugadweni kokukhanya okuphansi nokuhlaziya ubufakazi bokulandelela.
● I-Spectroscopy: Ku-Raman spectroscopy kanye nokutholwa kwe-fluorescence ephansi.
Kufanele Uyikhethe Nini Inzwa ye-EMCCD?
Ngokuthuthuka kwezinzwa ze-CMOS eminyakeni yamuva nje, inzuzo yomsindo ofundwayo wezinzwa ze-EMCCD inciphile njengoba manje namakhamera e-sCMOS esekwazi ukufunda umsindo ongaphansi kwe-electron, eceleni kohlu olukhulu lwezinye izinzuzo. Uma ngabe isicelo sike sasebenzisa ama-EMCCDs ngaphambilini, kuhle ukuthi kubuyekezwe ukuthi ingabe lokhu kuyisinqumo esingcono kakhulu esinikezwe ukuthuthukiswa kwe-sCMOS.
Ngokomlando, ama-EMCCD asengakwazi ukwenza ukubala kwe-photon ngempumelelo kakhulu, eceleni kwezinye izinhlelo zokusebenza ezimbalwa ze-niche ezinamaleveli esignali ajwayelekile angaphansi kuka-3-5e- ngephikseli ngayinye phezulu. Noma kunjalo, ngamasayizi amaphikseli amakhudlwana nomsindo wokufundwa kwe-electron engaphansi otholakala kuamakhamera esayensingokusekelwe kubuchwepheshe be-sCMOS, kungenzeka lezi zinhlelo zokusebenza nazo zingenziwa maduze nge-sCMOS ephezulu.
Imibuzo Evame Ukubuzwa
Sithini Isikhathi Esincane Sokuvezwa samakhamera okudlulisa uhlaka?
Kuzo zonke izinzwa zokudlulisa uhlaka, okuhlanganisa nama-EMCCD, umbuzo wesikhathi esincane esingaba khona sokuchayeka uyinkimbinkimbi. Ngokutholwa kwesithombe esisodwa, ukuchayeka kungaqedwa ngokuhlanganisa izindleko ezitholiwe endaweni efihliwe ukuze zifundwe ngokushesha okukhulu, futhi ubuncane bezikhathi zokuchayeka (i-sub-microsecond) obuncane bungenzeka.
Kodwa-ke, ngokushesha nje lapho ikhamera isakaza ngesivinini esigcwele, okungukuthi ithola amafreyimu amaningi / imuvi ngenani eligcwele lozimele, ngokushesha nje lapho isithombe sokuqala siqeda ukuveza, isifunda esimboziwe sithathwa yilolo hlaka kuze kuqedwe ukufunda. Ngakho-ke ukuchayeka akukwazi ukuphela. Lokhu kusho ukuthi, ngokunganaki isikhathi sokuchayeka esiceliwe kusofthiwe, isikhathi sangempela sokuchayeka sozimele abalandelayo ngemva kokuqala kokutholwa kozimele abaningi ngesivinini esigcwele sinikezwa isikhathi sozimele, okungukuthi 1 / Izinga lozimele, lekhamera.
Ingabe i-sCMOS Technology Ithatha Indawo Yezinzwa ze-EMCCD?
Amakhamera we-EMCCD abe nokucaciswa okubili okusize ukugcina inzuzo yawo kuzimo zokucabanga ezinokukhanya okuphansi kakhulu (ngamazinga esiginali aphezulu ama-photoelectrons angu-5 noma ngaphansi). Okokuqala, amaphikseli abo amakhulu, afika ku-16 μm, futhi okwesibili, umsindo wabo we-<1e- read.
Isizukulwane esisha seIkhamera ye-sCMOSkuye kwavela okunikeza lezi zici ezifanayo, ngaphandle kwezithiyo eziningi ze-EMCCDs, ikakhulukazi isici somsindo oweqile. Amakhamera afana ne-Aries 16 yaseTucsen anikela ngamaphikseli angu-16 μm akhanyiswe ngemuva anomsindo ofundwayo ongu-0.8e-. Ngomsindo ophansi kanye namaphikseli amakhulu 'endabuko', lawa makhamera aphinda adlula amakhamera amaningi e-sCMOS aboshwe, ngenxa yobudlelwano phakathi komsindo wokubopha kanye nokufunda.
Uma ufuna ukufunda okwengeziwe nge-EMCCD, sicela uchofoze:
Ingabe I-EMCCD Ingashintshwa Futhi Besingake Sikufune Lokho?
I-Tucsen Photonics Co., Ltd. Wonke amalungelo agodliwe. Uma ucaphuna, sicela wazise umthombo:www.tucsen.com
