Inhliziyo ye-Semiconductor Lasers: Ukuqonda i-PN Junction

Ngokuthuthuka okusheshayo kobuchwepheshe be-optoelectronic, ama-lasemiconductor lasers athole ukusetshenziswa okusabalele emikhakheni efana nezokuxhumana, imishini yezokwelapha, i-laser esukela, ukucutshungulwa kwezimboni, kanye nogesi wabathengi. Umnyombo walobu buchwepheshe kukhona ukuhlangana kwe-PN, okudlala indima ebalulekile—hhayi nje njengomthombo wokukhishwa kokukhanya kodwa futhi njengesisekelo sokusebenza kwedivayisi. Lesi sihloko sinikeza ukubuka konke okucacile nokufushane kwesakhiwo, izimiso, kanye nemisebenzi ebalulekile ye-PN junction kuma-semiconductor lasers.

1. Iyini i-PN Junction?

I-PN junction isixhumanisi esakhiwe phakathi kwe-semiconductor yohlobo lwe-P kanye ne-semiconductor yohlobo lwe-N:

I-semiconductor yohlobo lwe-P ifakwe ukungcola okuvumayo, okufana ne-boron (B), okwenza izimbobo zibe abathwali abaningi abashajayo.

I-semiconductor yohlobo lwe-N ifakwe ukungcola komnikeli, okufana ne-phosphorus (P), okwenza ama-electron abathwali abaningi.

Lapho izinto zohlobo lwe-P kanye nohlobo lwe-N zithola ukuthintana, ama-electron asuka ku-N-region asakazekela ku-P-region, futhi izimbobo ezivela ku-P-region zisakazekela endaweni engu-N. Lokhu kusakazwa kudala indawo yokuncipha lapho ama-electron nezimbobo kuhlangana khona kabusha, kushiye ama-ion ashajiwe adala inkambu kagesi yangaphakathi, eyaziwa ngokuthi umgoqo ongase ube khona owakhelwe ngaphakathi.

2. Iqhaza le-PN Junction kumaLaser

(1) Umjovo wenkampani yenethiwekhi

Lapho i-laser isebenza, i-PN junction ibheke phambili: i-P-region ixhunywe ku-voltage eqondile, futhi i-N-region ibe voltage negative. Lokhu kukhansela inkambu kagesi yangaphakathi, okuvumela ama-electron nezimbobo ukuthi zijovwe endaweni esebenzayo lapho kuhlangana khona indawo, lapho okungenzeka ziphinde zihlangane khona.

(2) Ukukhishwa Kokukhanya: Umsuka Wokuphuma Okuthuthukisiwe

Esifundeni esisebenzayo, ama-electron ajovwe nezimbobo aphinde ahlangane futhi akhulule ama-photon. Ekuqaleni, le nqubo iwukuphuma okuzenzakalelayo, kodwa njengoba ukuminyana kwama-photon kwanda, ama-photon angashukumisa ukuhlanganisa kabusha kwe-electron-hole, akhiphe ama-photon engeziwe anesigaba esifanayo, isiqondiso, namandla—lokhu kukhishwa okukhuthazwayo.

Le nqubo yakha isisekelo selaser (Ukukhulisa Ukukhanya Ngokuphuma Okuthuthukisiwe Kokukhishwa Kwemisebe).

(3) I-Gain and Resonant Cavities Form Laser Output

Ukuze kukhuliswe ukukhishwa okukhuthazwayo, amalaser we-semiconductor afaka imigodi ezwakalayo ezinhlangothini zombili ze-PN junction. Kuma-laser akhipha umphetho, isibonelo, lokhu kungafezwa kusetshenziswa i-Distributed Bragg Reflectors (DBRs) noma ama-mirror coatings ukukhombisa ukukhanya emuva naphambili. Lokhu kusetha kuvumela ubude beza obuthile bokukhanya ukuthi bukhuliswe, ekugcineni kuphumele ekuphumeni kwe-laser okuhambisana kakhulu futhi eqondisayo.

3. Izakhiwo ze-PN Junction kanye Nokuthuthukiswa Kwedizayini

Ngokuya ngohlobo lwe-laser semiconductor, ukwakheka kwe-PN kungahluka:

I-Heterojunction Eyodwa (SH):
I-P-region, N-region, kanye nesifunda esisebenzayo zenziwe ngezinto ezifanayo. Indawo yokuhlanganisa ibanzi futhi ayisebenzi kahle.

I-Double Heterojunction (DH):
Isendlalelo esisebenzayo se-bandgap esincane sihlanganiswe phakathi kwezifunda ezingu-P- ne-N. Lokhu kuhlanganisa kokubili abathwali nama-photon, okuthuthukisa kakhulu ukusebenza kahle.

Isakhiwo se-Quantum Well:
Isebenzisa ungqimba olusebenzayo oluzacile kakhulu ukuze idale imiphumela yokuvalelwa kwe-quantum, ithuthukise izici ze-threshold kanye nesivinini sokushintsha.

Lezi zakhiwo zonke ziklanyelwe ukuthuthukisa ukusebenza kahle komjovo wenkampani yenethiwekhi, ukuhlanganisa kabusha, nokukhipha ukukhanya endaweni ye-PN junction.

4. Isiphetho

I-PN junction ngempela "inhliziyo" ye-laser ye-semiconductor. Ikhono layo lokujova abathwali ngaphansi kokuchema okuya phambili liyimbangela eyinhloko yokukhiqizwa kwe-laser. Kusukela ekwakhiweni kwesakhiwo nokukhethwa kwezinto ezibonakalayo kuya ekulawuleni i-photon, ukusebenza kwayo yonke idivayisi ye-laser kuzungeza ekuthuthukiseni ukuhlangana kwe-PN.

Njengoba ubuchwepheshe be-optoelectronic buqhubeka buthuthuka, ukuqonda okujulile kwe-PN junction physics akugcini nje ngokuthuthukisa ukusebenza kwe-laser kodwa futhi kwakha isisekelo esiqinile sokuthuthukiswa kwesizukulwane esilandelayo samalaser anamandla amakhulu, anesivinini esikhulu, nangabizi kakhulu.