Mfundo ndi momwe zinthu zilili panopa za avalanche photodetector (APD photodetector) Gawo Lachiwiri

Mfundo ndi momwe zinthu zilili panoPhotodetector ya avalanche (APD Photodetector) Gawo Lachiwiri

2.2 APD chip kapangidwe
Kapangidwe ka chip koyenera ndiye chitsimikizo choyambirira cha zida zogwira ntchito kwambiri. Mapangidwe a APD makamaka amayang'ana nthawi ya RC nthawi zonse, kugwidwa kwa dzenje pa heterojunction, nthawi yonyamula katundu kudzera m'dera lakutha ndi zina zotero. Kapangidwe kake kakufotokozedwa mwachidule pansipa:

(1) Mapangidwe oyambira
Mapangidwe osavuta kwambiri a APD amachokera ku PIN photodiode, chigawo cha P ndi dera la N ndizochepa kwambiri, ndipo dera la N-mtundu kapena P-mtundu wachiwiri-repellant limayambitsidwa pafupi ndi dera la P kapena dera la N kuti apange ma elekitironi achiwiri ndi dzenje. awiriawiri, kuti azindikire kukulitsa kwa chithunzithunzi choyambirira. Pazinthu zotsatizana za InP, chifukwa mphamvu ya ionization ya dzenje ndi yayikulu kuposa ma electron effect ionization coefficient, gawo lopeza la mtundu wa N-doping nthawi zambiri limayikidwa m'chigawo cha P. Pamalo abwino, mabowo okha ndi omwe amalowetsedwa m'dera lopindula, choncho dongosololi limatchedwa dongosolo lopangidwa ndi dzenje.

(2) Mayamwidwe ndi phindu amasiyanitsidwa
Chifukwa cha kusiyana kwa magulu a InP (InP ndi 1.35eV ndipo InGaAs ndi 0.75eV), InP nthawi zambiri imagwiritsidwa ntchito ngati zone zone ndipo InGaAs ngati zone zone.

(3) Mayamwidwe, ma gradient ndi phindu (SAGM) amaperekedwa motsatana
Pakalipano, zipangizo zambiri zamalonda za APD zimagwiritsa ntchito InP/InGaAs zakuthupi, InGaAs monga gawo loyamwitsa, InP pansi pa malo amagetsi apamwamba (> 5x105V / cm) popanda kuwonongeka, angagwiritsidwe ntchito ngati zone zone chuma. Pazinthu izi, kapangidwe ka APD iyi ndikuti njira ya avalanche imapangidwa mu N-type InP ndi kugunda kwa mabowo. Poganizira kusiyana kwakukulu kwa kusiyana kwa gulu pakati pa InP ndi InGaAs, kusiyana kwa msinkhu wa mphamvu pafupifupi 0.4eV mu gulu la valence kumapangitsa mabowo opangidwa mu InGaAs mayamwidwe wosanjikiza kutsekeka m'mphepete mwa heterojunction asanafike pa InP multiplier wosanjikiza ndi liwiro kwambiri. kuchepetsedwa, zomwe zimabweretsa nthawi yayitali yoyankha komanso bandwidth yopapatiza ya APD iyi. Vutoli litha kuthetsedwa powonjezera gawo la kusintha kwa InGaAsP pakati pa zida ziwirizi.

(4) Mayamwidwe, ma gradient, charge and gain (SAGCM) aperekedwa motsatana.
Pofuna kupititsa patsogolo kugawa kwamagetsi kwa gawo la mayamwidwe ndi gawo lopindula, gawo lazolipiritsa limalowetsedwa mu kapangidwe kachipangizo, komwe kumapangitsa kuti liwiro la chipangizocho liziyenda bwino komanso kuyankha.

(5) Resonator enhanced (RCE) SAGCM kapangidwe
Pamwambapa mulingo woyenera kwambiri wa zodziwira zachikhalidwe, tiyenera kukumana ndi mfundo yakuti makulidwe a mayamwidwe wosanjikiza ndi chinthu chotsutsana ndi liwiro la chipangizocho komanso kuchuluka kwachulukidwe. Makulidwe owonda a gawo loyamwa amatha kuchepetsa nthawi yonyamula katundu, kotero kuti bandwidth yayikulu ingapezeke. Komabe, panthawi imodzimodziyo, kuti mupeze kuchuluka kwapamwamba kwa quantum, kuyamwa kumafunika kukhala ndi makulidwe okwanira. Njira yothetsera vutoli ikhoza kukhala mawonekedwe a resonant (RCE), ndiko kuti, Bragg Reflector (DBR) yogawidwa pansi ndi pamwamba pa chipangizocho. Galasi la DBR lili ndi mitundu iwiri ya zida zokhala ndi index yotsika yotsika komanso mawonekedwe apamwamba a refractive, ndipo ziwirizi zimakula mosinthana, ndipo makulidwe a gawo lililonse amakumana ndi mawonekedwe a kuwala kwa 1/4 mu semiconductor. Mapangidwe a resonator a detector amatha kukwaniritsa zofunikira zothamanga, makulidwe a mayamwidwe amatha kukhala ochepa kwambiri, ndipo mphamvu ya quantum ya electron imawonjezeka pambuyo pa kusinkhasinkha kangapo.

(6) Mawonekedwe ophatikizika a waveguide (WG-APD)
Njira ina yothetsera kutsutsana kwa zotsatira zosiyanasiyana za makulidwe a mayamwidwe pa liwiro la chipangizo ndi kuchuluka kwa magwiridwe antchito ndikuyambitsa mawonekedwe amtundu wa waveguide. Kapangidwe kameneka kamalowa mkati mwa kuwala kuchokera kumbali, chifukwa chigawo choyamwitsa ndi chotalika kwambiri, n'chosavuta kupeza mphamvu ya quantum yapamwamba, ndipo panthawi imodzimodziyo, kuyamwa kungapangidwe kukhala kochepa kwambiri, kuchepetsa nthawi yonyamula katundu. Chifukwa chake, kapangidwe kameneka kamathetsa kudalira kosiyanasiyana kwa bandwidth ndi magwiridwe antchito pa makulidwe a mayamwidwe osanjikiza, ndipo akuyembekezeka kukwaniritsa kuchuluka kwambiri komanso kuchuluka kwa APD. Njira ya WG-APD ndiyosavuta kuposa ya RCE APD, yomwe imachotsa zovuta zokonzekera galasi la DBR. Chifukwa chake, ndizotheka m'munda wothandiza komanso woyenera kulumikizana ndi mawonekedwe a ndege.

3. Mapeto
Kukula kwa chigumukirePhotodetectorzida ndi zida zimawunikiridwa. Ma electron ndi dzenje kugunda ionization mitengo ya InP zipangizo ali pafupi ndi za InAlAs, zomwe zimatsogolera ku ndondomeko iwiri ya ma symbions awiri onyamulira, zomwe zimapangitsa kuti nthawi yomanga chigumula ikhale yaitali ndipo phokoso likuwonjezeka. Poyerekeza ndi zida za InAlAs zoyera, InGaAs (P) /InAlAs ndi (Al) GaAs/InAlAs quantum well nyumba zimakhala ndi chiŵerengero chowonjezeka cha coefficients ionization ionization, kotero kuti phokoso likhoza kusinthidwa kwambiri. Pankhani ya kapangidwe kake, mawonekedwe a resonator enhanced (RCE) SAGCM ndi mawonekedwe ophatikizana m'mphepete mwa waveguide (WG-APD) amapangidwa kuti athe kuthana ndi zotsutsana zamitundu yosiyanasiyana ya makulidwe a mayamwidwe pa liwiro la chipangizo komanso kuchuluka kwa magwiridwe antchito. Chifukwa cha zovuta za ndondomekoyi, kugwiritsa ntchito kwathunthu kwazinthu ziwirizi kuyenera kufufuzidwanso.