Imeko ephambili kunye nemeko yangoku ye-avalanche photodetector (i-APD photodetector) Icandelo lesiBini

Umgaqo kunye nemeko yangokuisixhobo sokubona ifoto se-avalanche (Isixhobo sokubona ifoto se-APD) Inxalenye yesiBini

2.2 Ulwakhiwo lwetshiphu ye-APD
Ulwakhiwo lwe-chip olufanelekileyo luyisiqinisekiso esisisiseko sezixhobo ezisebenza kakuhle. Uyilo lwesakhiwo se-APD luqwalasela ikakhulu i-RC time constant, ukubanjwa kwemingxunya ngexesha le-heterojunction, ixesha lokuhamba komthwali kummandla wokuphelelwa ngamandla, njl. Uphuhliso lwesakhiwo salo luchazwe ngezantsi:

(1) Ulwakhiwo olusisiseko
Isakhiwo se-APD esilula sisekelwe kwi-PIN photodiode, ummandla we-P kunye nommandla we-N zixutywe kakhulu, kwaye ummandla we-N-type okanye we-P-type ophinda kabini ungeniswa kummandla we-P okanye ummandla we-N okufutshane ukuvelisa ii-electron zesibini kunye neepairs zemingxunya, ukuze kufezekiswe ukwanda kwe-photocurrent yokuqala. Kwizinto ze-InP series, kuba i-hole impact ionization coefficient inkulu kune-electron impact ionization coefficient, ummandla we-gain we-N-type doping uhlala ubekwa kummandla we-P. Kwimeko efanelekileyo, yimingxunya kuphela efakwa kummandla we-gain, ngoko ke olu lwakhiwo lubizwa ngokuba yi-hole-injected structure.

(2) Ukufunxa kunye nokuzuza kuyahlulwa
Ngenxa yeempawu ze-InP ezibanzi ze-band gap (InP yi-1.35eV kwaye i-InGaAs yi-0.75eV), i-InP idla ngokusetyenziswa njengesixhobo se-gain zone kunye ne-InGaAs njengesixhobo se-absorption zone.

(3) Ulwakhiwo lokufunxa, ukuthambeka kunye nokufumaneka (SAGM) lucetywayo ngokulandelelanayo
Okwangoku, uninzi lwezixhobo ze-APD zorhwebo zisebenzisa izinto ze-InP/InGaAs, ii-InGaAs njengomaleko wokufunxa, i-InP phantsi kombane ophezulu (>5x105V/cm) ngaphandle kokuqhekeka, ingasetyenziswa njengezinto zokufumana indawo yokufumana inzuzo. Kule nto, uyilo lwale APD kukuba inkqubo ye-avalanche yenziwe kwi-N-type InP ngokungqubana kwemingxunya. Ukuqwalasela umahluko omkhulu kwi-band gap phakathi kwe-InP kunye ne-InGaAs, umahluko wamandla malunga ne-0.4eV kwi-valence band wenza imingxunya eyenziwe kwi-InGaAs absorption layer ivalwe kumda we-heterojunction ngaphambi kokufikelela kumaleko wokuphindaphinda we-InP kwaye isantya sinciphile kakhulu, nto leyo ebangela ixesha elide lokuphendula kunye ne-bandwidth encinci yale APD. Le ngxaki ingasombululwa ngokongeza umaleko wotshintsho lwe-InGaAsP phakathi kwezinto ezimbini.

(4) Ulwakhiwo lwe-absorption, gradient, charge kunye ne-gain (SAGCM) lucetywayo ngokulandelelanayo
Ukuze kulungiswe ngakumbi ukusasazwa kwentsimi yombane yomaleko wokufunxa kunye nomaleko wokuzuza, umaleko wokutshaja ufakwa kuyilo lwesixhobo, nto leyo ephucula kakhulu isantya sesixhobo kunye nokuphendula kwaso.

(5) Ulwakhiwo lwe-SAGCM oluphuculweyo lwe-Resonator (RCE)
Kuyilo oluphezulu lwezixhobo zokubona izinto zemveli, kufuneka sijongane nenyaniso yokuba ubukhulu bomaleko wokufunxa buyinto ephikisanayo kwisantya sesixhobo kunye nokusebenza kakuhle kwe-quantum. Ubukhulu obuncinci bomaleko wokufunxa bunokunciphisa ixesha lokuhamba komthwali, ngoko ke i-bandwidth enkulu inokufumaneka. Nangona kunjalo, kwangaxeshanye, ukuze kufunyanwe ukusebenza kakuhle kwe-quantum, umaleko wokufunxa kufuneka ube nobukhulu obaneleyo. Isisombululo sale ngxaki sinokuba sisakhiwo se-resonant cavity (RCE), oko kukuthi, i-Bragg Reflector (DBR) esasazekileyo yenzelwe ezantsi naphezulu kwesixhobo. Isibuko se-DBR sineentlobo ezimbini zezinto ezine-refractive index ephantsi kunye ne-refractive index ephezulu kwisakhiwo, kwaye ezi zimbini zikhula ngokutshintshana, kwaye ubukhulu bomaleko ngamnye budibana nobude bokukhanya obuyi-1/4 kwi-semiconductor. Ulwakhiwo lwe-resonator lomtshini lunokuhlangabezana neemfuno zesantya, ubukhulu bomaleko wokufunxa bunokwenziwa bube buncinci kakhulu, kwaye ukusebenza kakuhle kwe-quantum kwe-electron kuyandiswa emva kokubonakalisa okuliqela.

(6) Ulwakhiwo lwesikhokelo samaza esidityaniswe nomphetho (WG-APD)
Esinye isisombululo sokusombulula ukuphikisana kweziphumo ezahlukeneyo zobukhulu beleya yokufunxa kwisantya sesixhobo kunye nokusebenza kakuhle kwe-quantum kukwazisa isakhiwo se-waveguide esidityanisiweyo nomphetho. Esi sakhiwo singena ekukhanyeni sivela ecaleni, kuba ileya yokufunxa inde kakhulu, kulula ukufumana ukusebenza kakuhle kwe-quantum, kwaye kwangaxeshanye, ileya yokufunxa ingenziwa ibe ncinci kakhulu, nto leyo enciphisa ixesha lokuhamba komthwali. Ke ngoko, esi sakhiwo sisombulula ukuxhomekeka okwahlukileyo kwe-bandwidth kunye nokusebenza kakuhle kubukhulu beleya yokufunxa, kwaye kulindeleke ukuba sifumane i-APD yesantya esiphezulu kunye nokusebenza kakuhle kwe-quantum. Inkqubo ye-WG-APD ilula kuneye-RCE APD, esusa inkqubo yokulungiselela enzima yesipili se-DBR. Ke ngoko, inokwenzeka ngakumbi kwintsimi esebenzayo kwaye ifanelekile kuqhagamshelo oluqhelekileyo lwe-plane optical.

3. Isiphelo
Uphuhliso lwe-avalancheisixhobo sokubona iifotoIzinto kunye nezixhobo ziyahlolwa. Amanqanaba e-ionization ye-electron kunye ne-hole collision yezixhobo ze-InP asondele kakhulu kulawo e-InAlAs, nto leyo ekhokelela kwinkqubo ephindwe kabini ye-symbions ezimbini zokuthwala, nto leyo eyenza ixesha lokwakha i-avalanche libe lide kwaye ingxolo inyuke. Xa kuthelekiswa nezinto ze-InAlAs ezicocekileyo, izakhiwo ze-InGaAs (P) /InAlAs kunye ne-In (Al) GaAs/InAlAs quantum well zine-ratio eyongeziweyo ye-collision ionization coefficients, ngoko ke ukusebenza kwengxolo kunokutshintshwa kakhulu. Ngokwesakhiwo, isakhiwo se-resonator enhanced (RCE) SAGCM kunye nesakhiwo se-edge-coupled waveguide (WG-APD) ziyaphuhliswa ukuze kusonjululwe ukungqubana kweziphumo ezahlukeneyo zobukhulu be-absorption layer kwisantya sesixhobo kunye nokusebenza kakuhle kwe-quantum. Ngenxa yobunzima benkqubo, ukusetyenziswa ngokupheleleyo kwezi zakhiwo zimbini kufuneka kuhlolwe ngakumbi.