Yethula i-bandwidth kanye nesikhathi sokukhuphuka kwe-photodetector
I-bandwidth kanye nesikhathi sokukhuphuka (esaziwa nangokuthi isikhathi sokuphendula) se-photodetector yizinto ezibalulekile ekuhlolweni kwe-optical detector. Abantu abaningi abanalo ulwazi ngalezi pharamitha ezimbili. Lesi sihloko sizokwethula ngqo i-bandwidth kanye nesikhathi sokukhuphuka se-photodetector.
Isikhathi sokukhuphuka (τr) kanye nesikhathi sokuwa (τf) zombili ziyizinkomba ezibalulekile zokulinganisa isivinini sokuphendula sama-photodetector. I-bandwidth ye-3dB, njengenkomba kusizinda semvamisa, ihlobene eduze nesikhathi sokukhuphuka ngokwejubane lokuphendula. Ubudlelwano phakathi kwe-bandwidth BW ye-photodetector nesikhathi sayo sokuphendula i-Tr bungaguqulwa cishe ngale ndlela elandelayo: Tr=0.35/BW.
Isikhathi sokukhuphuka yigama kubuchwepheshe be-pulse, elichaza futhi lisho ukuthi isignali ikhuphuka isuka endaweni eyodwa (ngokuvamile: Vout*10%) iye kwenye indawo (ngokuvamile: Vout*90%). Ubukhulu bomphetho okhuphukayo wesignali ye-Rise Time ngokuvamile bubhekisela esikhathini esithathwayo ukukhuphuka isuka ku-10% iye ku-90%. Isimiso sokuhlola: Isignali idluliselwa endleleni ethile, bese kusetshenziswa enye ikhanda lesampula ukuthola nokukala inani le-voltage pulse ekugcineni okude.
Isikhathi sokukhuphuka kwesignali sibalulekile ekuqondeni izinkinga zobuqotho besignali. Iningi lezinkinga ezihlobene nokusebenza kohlelo lokusebenza lomkhiqizo ekwakhiweni kwama-photodetector e-bandwidth asheshayo ahlotshaniswa nayo. Lapho ukhetha i-photodetector, kumele inikezwe ukunakwa okwanele. Isikhathi sokukhuphuka sinomthelela omkhulu ekusebenzeni kwesekethe. Uma nje ingaphakathi kwebanga elithile, kumele ithathwe ngokungathi sína, noma ngabe ibanga elingacacile kakhulu.
Njengoba isikhathi sokukhuphuka kwesignali sincipha, izinkinga ezifana nokuzindla, ukukhuluma nge-crosstalk, ukuwa kwe-orbit, imisebe kagesi, kanye nokugxuma komhlaba okubangelwa isignali yangaphakathi noma isignali yokuphuma kwe-photodetector kuba nzima kakhulu, futhi inkinga yomsindo iba nzima ukuyixazulula. Ngokombono wokuhlaziywa kwe-spectral, ukunciphisa isikhathi sokukhuphuka kwesignali kufana nokwanda komkhawulokudonsa wesignali, okungukuthi, kunezingxenye eziningi zemvamisa ephezulu esignalini. Yilezi zingxenye zemvamisa ephezulu ezenza umklamo ube nzima. Imigqa yokuxhumana kumele iphathwe njengemigqa yokudlulisela, okuholele ezinkingeni eziningi ezazingekho ngaphambili.
Ngakho-ke, enkambisweni yokufaka ama-photodetector, kumele ube nomqondo onjalo: lapho isignali yokukhipha ye-photodetector inomphetho okhuphukayo noma ngisho nokudubula okukhulu, futhi isignali ingazinzile, kungenzeka kakhulu ukuthi i-photodetector oyithengile ayihlangabezani nezidingo zomklamo ezifanele zobuqotho besignali futhi ayikwazi ukuhlangabezana nezidingo zakho zangempela zohlelo lokusebenza ngokwemigomo ye-bandwidth kanye nemingcele yesikhathi sokukhuphuka. Imikhiqizo ye-photoelectric detector ye-JIMU Guangyan yonke isampula ama-photoelectric chips akamuva athuthukisiwe, ama-high-speed operating amplifier chips, kanye nama-filter circuits aqondile. Ngokwezimpawu zangempela zesignali yesicelo samakhasimende, zihambisana ne-bandwidth kanye nesikhathi sokukhuphuka. Isinyathelo ngasinye sicabangela ubuqotho besignali. Gwema izinkinga ezivamile ezifana nomsindo wesignali ophezulu kanye nokuzinza okubi okubangelwa ukungalingani phakathi kwe-bandwidth kanye nesikhathi sokukhuphuka ekusetshenzisweni kwama-photodetector kubasebenzisi.
Isikhathi sokuthunyelwe: Septhemba-29-2025