Intliziyo yeeLaser zeSemiconductor: Ukuqonda iPN Junction

Ngophuhliso olukhawulezileyo lwetekhnoloji ye-optoelectronic, ii-semiconductor lasers zifumene usetyenziso olubanzi kwiindawo ezifana nonxibelelwano, izixhobo zonyango, i-laser ranging, i-industrial processing, kunye ne-consumer electronics. Eyona nto iphambili kule teknoloji kukukho i-PN junction, edlala indima ebalulekileyo—kungekuphela nje njengomthombo wokukhupha ukukhanya kodwa njengesiseko sokusebenza kwesixhobo. Eli nqaku libonelela ngesishwankathelo esicacileyo nesifutshane sesakhiwo, imigaqo, kunye nemisebenzi ephambili ye-PN junction kwi-semiconductor lasers.

1. Yintoni i-PN Junction?

I-PN junction yindlela edibanisa ngayo i-semiconductor yohlobo lwe-P kunye ne-semiconductor yohlobo lwe-N:

I-P-type semiconductor ixutywe nezinto ezingcolisayo ze-acceptor, ezifana ne-boron (B), nto leyo eyenza imingxunya ibe zizithuthi ezithwala iitshaja ezininzi.

I-semiconductor yohlobo lwe-N izaliswe zizinto ezingcolisayo zabaxhasi, ezifana ne-phosphorus (P), nto leyo eyenza ii-electron zibe zezona zithwala uninzi lwazo.

Xa izinto zohlobo lwe-P kunye nohlobo lwe-N zidityaniswa, ii-elektroni ezivela kummandla we-N ziyasasazeka ziye kummandla we-P, kwaye imingxunya evela kummandla we-P iyasasazeka iye kummandla we-N. Oku kusasazwa kudala ummandla wokuphelelwa ngamandla apho ii-elektroni kunye nemingxunya zidibana kwakhona, zishiya ii-ion ezitshajiweyo ezidala intsimi yombane yangaphakathi, eyaziwa ngokuba ngumqobo onokubakho owakhelwe ngaphakathi.

2. Indima yePN Junction kwiLaser

(1) Inaliti yoMthwali

Xa i-laser isebenza, i-PN junction ibheke phambili: i-P-region iqhagamshelwe kwi-voltage elungileyo, kwaye i-N-region iqhagamshelwe kwi-voltage engalunganga. Oku kuyayicima intsimi yombane yangaphakathi, okuvumela ii-electron kunye nemingxunya ukuba ifakwe kwindawo esebenzayo kwi-junction, apho kunokwenzeka ukuba ziphinde zihlangane khona.

(2) Ukukhupha Ukukhanya: Imvelaphi Yokukhupha Okukhuthazwayo

Kwindawo esebenzayo, ii-electron ezifakwe kwi-injection kunye nemingxuma ziyadibana kwakhona kwaye zikhuphe ii-photon. Ekuqaleni, le nkqubo ikhutshwa ngokungazenzekeliyo, kodwa njengoko uxinano lwe-photon lusanda, ii-photon zinokuvuselela ukuphinda-phinda kwee-electron kunye nemingxuma, zikhuphe ii-photon ezongezelelweyo ezinesigaba, icala, kunye namandla afanayo—oku kukukhutshwa okukhuthazwayo.

Le nkqubo yakha isiseko selaser (iLight Amplification by Stimulated Emission of Radiation).

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

Ukwandisa ukukhutshwa okukhuthazwayo, iileyiza ze-semiconductor ziquka imingxunya erhabaxa kumacala omabini e-PN junction. Kwiileyiza ezikhupha imiphetho, umzekelo, oku kunokufezekiswa kusetyenziswa iiDistributed Bragg Reflectors (DBRs) okanye iiglasi zesipili ukuze zibonise ukukhanya ngasemva nangaphambili. Olu seto luvumela ukuba ubude bokukhanya obuthile bukhuliswe, ekugqibeleni kuphumele kwimveliso yeleyiza ehambelanayo neyasekunene.

3. Ulwakhiwo lwePN Junction kunye noLungiso loYilo

Ngokuxhomekeke kuhlobo lwelaser ye-semiconductor, ulwakhiwo lwe-PN lunokwahluka:

I-Single Heterojunction (SH):
Ummandla we-P, ummandla we-N, kunye nommandla osebenzayo zenziwe ngezinto ezifanayo. Ummandla wokuphinda uhlangane ubanzi kwaye awusebenzi kakuhle.

I-Heterojunction ephindwe kabini (DH):
Umaleko osebenzayo we-bandgap omxinwa ubekwe phakathi kweendawo ze-P kunye ne-N. Oku kuthintela zombini ii-carriers kunye nee-photons, nto leyo ephucula kakhulu ukusebenza kakuhle.

Ulwakhiwo lweQuantum Well:
Isebenzisa umaleko osebenzayo obhityileyo kakhulu ukudala iziphumo zokuvalelwa kwe-quantum, ukuphucula iimpawu zomda kunye nesantya sokuguqula.

Zonke ezi zakhiwo zenzelwe ukuphucula ukusebenza kakuhle kwe-carrier injection, recombination, kunye nokukhupha ukukhanya kummandla we-PN junction.

4. Isiphelo

I-PN junction ngokwenene "yintliziyo" ye-semiconductor laser. Amandla ayo okufaka ii-carriers phantsi kwe-forward bias yeyona nto iphambili ebangela ukuveliswa kwe-laser. Ukususela kuyilo lwesakhiwo kunye nokukhethwa kwezinto ukuya kulawulo lwe-photon, ukusebenza kwesixhobo se-laser sonke kujikeleze ukuphucula i-PN junction.

Njengoko ubuchwepheshe be-optoelectronic buqhubeka buhambela phambili, ukuqonda okunzulu nge-PN junction physics akupheleli nje ekuphuculeni ukusebenza kwe-laser kodwa kukwabeka isiseko esiqinileyo sophuhliso lwesizukulwana esilandelayo se-semiconductor lasers ezinamandla aphezulu, akhawulezayo, kunye namaxabiso aphantsi.