Amapharamitha ayisisekelo ezimpawu zesignali yokukhanyaama-photodetectors:
Ngaphambi kokuhlola izinhlobo ezahlukene zama-photodetector, imingcele yezimpawu zokusebenza kokusebenza kweama-photodetector esignali yokukhanyazifingqiwe. Lezi zici zifaka phakathi ukuphendula, impendulo ye-spectral, amandla okulingana nomsindo (i-NEP), ukuthola okuthile, kanye nokuthola okuthile. D*), ukusebenza kahle kwe-quantum, kanye nesikhathi sokuphendula.
1. i-responsivity Rd isetshenziselwa ukuchaza ukuzwela kokuphendula kwedivayisi kumandla emisebe ye-optical. Imelelwa yisilinganiso sesiginali esiphumayo kusignali yesigameko. Lesi sici asibonisi izici zomsindo zedivayisi, kodwa sibonisa kuphela ukusebenza kahle kokuguqula amandla emisebe ye-electromagnetic ibe yi-current noma i-voltage. Ngakho-ke, ingahluka ngobude be-wavelength yesiginali yokukhanya kwesigameko. Ngaphezu kwalokho, izici zokuphendula kwamandla nazo ziwumsebenzi we-bias esetshenzisiwe kanye nokushisa kwe-ambient.
2. Isici sempendulo ye-spectral siyipharamitha echaza ubudlelwano phakathi kwesici sempendulo yamandla se-optical signal detector kanye nomsebenzi we-wavelength yesignali ye-incident optical. Izici zempendulo ye-spectral zama-photodetector e-optical signal kuma-wavelength ahlukene zivame ukuchazwa ngobuningi "nge-spectral response curve". Kufanele kuqashelwe ukuthi izici zempendulo ye-spectral eziphezulu kakhulu kuphela ku-curve ezilinganiswa ngenani eliphelele, kanti ezinye izici zempendulo ye-spectral kuma-wavelength ahlukene zivezwa ngamanani ajwayelekile ahlobene ngokusekelwe enanini eliphakeme kakhulu lezimpawu zempendulo ye-spectral.
3. Amandla alingana nomsindo amandla esignali yokukhanya kwesigameko adingekayo lapho i-voltage yesignali yokukhipha ekhiqizwa yisitholi sesignali yokukhanya ilingana nezinga le-voltage yomsindo elingokwemvelo ledivayisi uqobo. Yisici esiyinhloko esinquma ukuqina kwesignali yokukhanya okuncane okungalinganiswa yisitholi sesignali yokukhanya, okungukuthi, ukuzwela kokuthola.
4. Ukuzwela kokuthola okuthile kuyipharamitha ephawulekayo echaza izici ezingokwemvelo zezinto ezithinta ukukhanya zomshini wokuthola ukukhanya. Imelela ubuningi bamanje be-photon yesigameko obuphansi kakhulu obungalinganiswa yisitholi sesignali yokukhanya. Inani layo lingahluka ngokuya ngezimo zokusebenza zesitholi se-wavelength yesibonisi sokukhanya esilinganisiwe (njengokushisa kwe-ambient, i-bias esetshenzisiwe, njll.). Uma i-bandwidth yesitholi inkulu, indawo yesitholi sesignali yokukhanya inkulu, amandla alinganayo nomsindo ancipha i-NEP, futhi ukuzwela kokuthola okuthile kuphakeme. Ukuzwela kokuthola okuthile okuphezulu komtshina kusho ukuthi kufanelekile ukuthola izimpawu zokukhanya ezibuthakathaka kakhulu.
5. Ukusebenza kahle kwe-Quantum Q kungenye ipharamitha ebalulekile yesici sokuthola isignali ye-optical. Kuchazwa njengesilinganiso senani "lezimpendulo" ezingabalwa ezikhiqizwa yi-photomon kumtholi nenani lesigameko se-photon ebusweni bento ezwela ukukhanya. Isibonelo, kuma-detector esignali yokukhanya asebenza ekukhishweni kwe-photon, ukusebenza kahle kwe-quantum kuyisilinganiso senani lama-photoelectron akhishwa ebusweni bento ezwela ukukhanya nenani lama-photon esignali elinganisiwe ekhonjiswe ebusweni. Ku-detector yesignali ye-optical esebenzisa i-pn junction semiconductor material njengezinto ezizwela ukukhanya, ukusebenza kahle kwe-quantum komtholi kubalwa ngokuhlukanisa inani lama-electron hole pair akhiqizwa yisignali yokukhanya elinganisiwe ngenani lama-photon esignali yesigameko. Okunye ukumelwa okuvamile kokusebenza kahle kwe-quantum komtholi wesignali ye-optical ngokusebenzisa i-Rd yokuphendula komtholi.
6. Isikhathi sokuphendula siyipharamitha ebalulekile yokuchaza isivinini sokuphendula sesitholi sesignali sokubona ekushintsheni kokuqina kwesibonisi sokukhanya esilinganisiwe. Lapho isibonisi sokukhanya esilinganisiwe siguqulwa sibe uhlobo lwe-pulse yokukhanya, ukuqina kwesignali kagesi ye-pulse ekhiqizwa yisenzo sayo kumtholi kudingeka "kukhuphuke" kuye "esiqongweni" esihambisanayo ngemva kwesikhathi esithile sokuphendula, futhi kusukela "esiqongweni" bese kubuyela emuva "esilinganisweni se-zero" sokuqala esihambisana nesenzo se-pulse yokukhanya. Ukuze kuchazwe impendulo yesitholi ekushintsheni kokuqina kwesibonisi sokukhanya esilinganisiwe, isikhathi lapho ukuqina kwesignali kagesi ekhiqizwa yi-pulse yokukhanya yesigameko kukhuphuka kusuka enanini layo eliphakeme kakhulu elingu-10% kuya ku-90% kubizwa ngokuthi "isikhathi sokukhuphuka", kanti isikhathi lapho i-waveform ye-pulse yesignali kagesi iwa khona kusuka enanini layo eliphakeme kakhulu elingu-90% kuya ku-10% kubizwa ngokuthi "isikhathi sokuwa" noma "isikhathi sokubola".
7. Ukulingana kokuphendula kungenye ipharamitha ebalulekile yesici echaza ubudlelwano obusebenzayo phakathi kokusabela kwesitholi sesignali yokukhanya kanye nobukhulu besignali yokukhanya elinganiswe ngesigameko. Kudinga ukuphuma kweisitholi sesiginali yokukhanyaukuze kube nokulingana ngaphakathi kobubanzi obuthile bobukhulu besiginali yokukhanya elinganisiwe. Ngokuvamile kuchazwa ukuthi ukuphambuka kwephesenti kusuka kumugqa wokufaka-wokukhipha ngaphakathi kobubanzi obucacisiwe bobukhulu besiginali yokukhanya yokufaka kungumugqa wokuphendula wesitholi sesiginali yokukhanya.
Isikhathi sokuthunyelwe: Agasti-12-2024