Isimo esiyisisekelo kanye nesimo samanjeumshini wokuthola izithombe we-avalanche (Isitholi sezithombe se-APD) Ingxenye Yesibili
2.2 Isakhiwo se-chip se-APD
Isakhiwo se-chip esinengqondo siyisiqinisekiso esiyisisekelo samadivayisi asebenza kahle kakhulu. Ukwakheka kwesakhiwo se-APD kubheka kakhulu ukungalingani kwesikhathi se-RC, ukubanjwa kwemigodi ngesikhathi se-heterojunction, isikhathi sokuthutha komthwali endaweni yokuphelelwa amandla njalo njalo. Ukuthuthukiswa kwesakhiwo saso kufingqiwe ngezansi:
(1) Isakhiwo esiyisisekelo
Isakhiwo se-APD esilula kakhulu sisekelwe ku-PIN photodiode, isifunda se-P kanye nesifunda se-N zixutshwe kakhulu, kanti isifunda sohlobo lwe-N noma uhlobo lwe-P sixutshwa kabili esifundeni se-P noma esifundeni se-N esiseduze ukuze kukhiqizwe ama-electron esibili kanye nama-hole pair, ukuze kufezwe ukukhuliswa kwe-photocurrent eyinhloko. Kwezinto zochungechunge lwe-InP, ngoba i-hole impact ionization coefficient inkulu kune-electron impact ionization coefficient, isifunda se-gain sohlobo lwe-N sivame ukufakwa esifundeni se-P. Esimweni esihle, imigodi kuphela efakwa esifundeni se-gain, ngakho-ke lesi sakhiwo sibizwa ngokuthi isakhiwo esifakwe imigodi.
(2) Ukumunca kanye nokuzuza kuyahlukaniswa
Ngenxa yezimpawu ze-InP ze-wide band gap (InP ingu-1.35eV kanti i-InGaAs ingu-0.75eV), i-InP ivame ukusetshenziswa njengezinto ze-gain zone kanye ne-InGaAs njengezinto ze-absorption zone.
(3) Izakhiwo zokumunca, ukuthambekela kanye nokuzuza (SAGM) ziphakanyiswa ngokulandelana
Njengamanje, amadivayisi amaningi e-APD ezentengiselwano asebenzisa izinto ze-InP/InGaAs, i-InGaAs njengengqimba yokumunca, i-InP ngaphansi kwensimu kagesi ephezulu (>5x105V/cm) ngaphandle kokuqhekeka, ingasetshenziswa njengezinto zokuthola indawo. Kule nto, ukwakheka kwale APD ukuthi inqubo ye-avalanche yakhiwa ku-InP yohlobo lwe-N ngokushayisana kwemigodi. Uma ubheka umehluko omkhulu kugebe lebhendi phakathi kwe-InP ne-InGaAs, umehluko wezinga lamandla ongaba ngu-0.4eV kubhendi ye-valence wenza imigodi ekhiqizwe kungqimba lokumunca le-InGaAs ivinjwe emaphethelweni e-heterojunction ngaphambi kokufinyelela kungqimba lokuphindaphinda le-InP futhi ijubane lincishiswe kakhulu, okuholela esikhathini eside sokuphendula kanye nomkhawulokudonsa omncane wale APD. Le nkinga ingaxazululwa ngokungeza ungqimba lokushintsha lwe-InGaAsP phakathi kwezinto ezimbili.
(4) Izakhiwo zokumunca, ukuthambekela, ukushaja kanye nokuzuza (SAGCM) ziphakanyiswa ngokulandelana
Ukuze kulungiswe kabanzi ukusatshalaliswa kwensimu kagesi kwesendlalelo sokumunca kanye nesendlalelo sokuzuza, isendlalelo sokushaja sifakwa ekwakhiweni kwedivayisi, okuthuthukisa kakhulu isivinini sedivayisi kanye nokusabela kwayo.
(5) Isakhiwo se-SAGCM esithuthukisiwe yi-Resonator (RCE)
Kulolu hlobo lokuklama olungenhla olungcono kakhulu lwemishini yokubona yendabuko, kumelwe sibhekane neqiniso lokuthi ubukhulu besendlalelo sokumunca buyinto ephikisanayo ngesivinini sedivayisi kanye nokusebenza kahle kwe-quantum. Ubukhulu obuncane besendlalelo sokumunca bunganciphisa isikhathi sokuhamba kwesithwali, ngakho-ke kungatholakala i-bandwidth enkulu. Kodwa-ke, ngesikhathi esifanayo, ukuze kutholakale ukusebenza kahle kwe-quantum okuphezulu, isendlalelo sokumunca sidinga ukuba nobukhulu obanele. Isixazululo sale nkinga singaba isakhiwo se-resonant cavity (RCE), okungukuthi, i-Bragg Reflector esabalalisiwe (DBR) yakhelwe phansi naphezulu kwedivayisi. Isibuko se-DBR sakhiwe ngezinhlobo ezimbili zezinto ezine-refractive index ephansi kanye ne-refractive index ephezulu yesakhiwo, futhi lezi ezimbili zikhula ngokushintshana, futhi ubukhulu besendlalelo ngasinye buhlangabezana nobude be-wavelength yokukhanya kwesigameko esingu-1/4 ku-semiconductor. Isakhiwo se-resonator semishini yokubona singahlangabezana nezidingo zesivinini, ubukhulu besendlalelo sokumunca bungenziwa bube buncane kakhulu, futhi ukusebenza kahle kwe-quantum kwe-electron kuyanda ngemva kokuboniswa okuningana.
(6) Isakhiwo se-waveguide esihlanganiswe ngomphetho (WG-APD)
Esinye isisombululo sokuxazulula ukungqubuzana kwemiphumela ehlukene yobukhulu besendlalelo sokumunca esivinini sedivayisi kanye nokusebenza kahle kwe-quantum ukwethula isakhiwo se-waveguide esihlanganiswe ngomphetho. Lesi sakhiwo singena ekukhanyeni kusuka ohlangothini, ngoba isendlalelo sokumunca side kakhulu, kulula ukuthola ukusebenza kahle kwe-quantum ephezulu, futhi ngesikhathi esifanayo, isendlalelo sokumunca singenziwa sibe sincane kakhulu, kuncishiswe isikhathi sokuthutha senkampani. Ngakho-ke, lesi sakhiwo sixazulula ukuncika okuhlukile kwe-bandwidth kanye nokusebenza kahle ebukhulu besendlalelo sokumunca, futhi kulindeleke ukuthi sifinyelele i-APD yesivinini esiphezulu kanye nokusebenza kahle kwe-quantum ephezulu. Inqubo ye-WG-APD ilula kuneye-RCE APD, eqeda inqubo yokulungiselela eyinkimbinkimbi yesibuko se-DBR. Ngakho-ke, kungenzeka kakhulu ensimini esebenzayo futhi ifanele ukuxhumana okuvamile kwendiza.
3. Isiphetho
Ukuthuthukiswa kwe-avalancheumshini wokuthola izithombeIzinto zokwakha namadivayisi kuyabuyekezwa. Amazinga e-ionization yokushayisana kwama-electron kanye nemigodi yezinto ze-InP asondele kakhulu kunalawo e-InAlAs, okuholela enkambisweni ephindwe kabili yezimpawu ezimbili zokuthwala, okwenza isikhathi sokwakhiwa kwe-avalanche sibe side futhi umsindo ukhuphuke. Uma kuqhathaniswa nezinto ze-InAlAs ezihlanzekile, izakhiwo ze-InGaAs (P) /InAlAs kanye ne-In (Al) GaAs/InAlAs quantum well zinesilinganiso esikhulayo sama-coefficients e-ionization yokushayisana, ngakho-ke ukusebenza komsindo kungashintshwa kakhulu. Ngokuphathelene nesakhiwo, isakhiwo se-resonator enhanced (RCE) SAGCM kanye nesakhiwo se-edge-coupled waveguide (WG-APD) zakhiwa ukuze kuxazululwe ukuphikisana kwemiphumela ehlukene yobukhulu besendlalelo sokumuncwa esivinini sedivayisi kanye nokusebenza kahle kwe-quantum. Ngenxa yobunzima benqubo, ukusetshenziswa okugcwele kwalezi zakhiwo ezimbili kudinga ukuhlolwa kabanzi.
Isikhathi sokuthunyelwe: Novemba-14-2023