Semiconductor Lasers yog dab tsi? (Part Ⅰ)

Txij li thaum lub invention ntawm thawjSemiconductor Lasersnyob rau hauv lub ntiaj teb no nyob rau hauv 1962, lub semiconductor laser tau dhau los ua kev hloov pauv loj, txhawb kev loj hlob ntawm lwm yam kev tshawb fawb thiab thev naus laus zis, thiab suav tias yog ib qho tseem ceeb inventions ntawm lub xyoo pua 20th. Nyob rau hauv xyoo tsis ntev los no, txoj kev loj hlob ntawm semiconductor laser yog sai thiab tau los ua lub ntiaj teb no tus ceev tshaj-tsim laser technology. Daim ntawv thov ntawm semiconductor lasers npog tag nrho cov teb ntawm optoelectronics thiab tau dhau los ua cov thev naus laus zis ntawm optoelectronics science. Vim qhov zoo ntawm qhov me me, cov qauv yooj yim, lub zog tsis muaj zog, lub neej ntev, yooj yim rau kev hloov kho, thiab tus nqi qis, semiconductor laser tau siv dav hauv kev lag luam optoelectronics thiab tau txais txiaj ntsig zoo los ntawm cov teb chaws thoob ntiaj teb.

1. Semiconductor lasers

Lub semiconductor laser yog ib hom ntawm cov laser me me uas yog tsim los ntawm Pn hlws ris lossis Pin ntawm cov khoom siv ncaj qha band gap semiconductor. Muaj ntau ntau hom semiconductor laser ua haujlwm. Tam sim no, cov khoom siv semiconductor uas tau ua rau lasers yog gallium arsenide, indium arsenide, indium antimonide, cadmium sulfide, cadmium telluride, lead selenide, lead telluride, aluminium gallium arsenic, indium phosphorus arsenic thiab lwm yam. Muaj peb hom excitation hom ntawm semiconductor laser, uas yog, hluav taws xob txhaj tshuaj, kho qhov muag twj tso kua mis, thiab high-zog electron beam excitation. Lub excitation hom ntawm feem ntau semiconductor lasers yog hluav taws xob txhaj tshuaj, uas yog, rau pem hauv ntej voltage yog siv rau lub Pn hlws ris los tsim stimulated emission nyob rau hauv lub junction dav hlau cheeb tsam, uas yog, nws yog ib tug pem hauv ntej-biased diode. Yog li ntawd, lub semiconductor laser kuj hu ua semiconductor laser diode. Rau cov khoom siv hluav taws xob, txij li cov hluav taws xob hloov pauv ntawm cov hluav taws xob hluav taws xob ntau dua li ntawm cov hluav taws xob tsis sib xws, lub zog hloov pauv tsis yog tus nqi tseeb, uas ua rau cov zis wavelength ntawm semiconductor laser kis thoob plaws ntau yam. Lawv emit wavelengths xws li 0.3 mus rau 34μm. Lub wavelength ntau yog nyob ntawm qhov sib txawv ntawm cov khoom siv. Qhov ntau AlGaAs ob lub heterojunction laser muaj qhov tso zis wavelength ntawm 750 ~ 890nm.

Semiconductor lasers ntau lawm tshuab tau ntsib los ntawm txoj kev diffusion mus rau kua theem epitaxy (LPE), roj theem epitaxy (VPE), molecular beam epitaxy (MBE), MOCVD txoj kev (organic hlau vapor deposition), tshuaj beam epitaxy (CBE) thiab lawv ntau yam ua ke ntawm ntau yam txheej txheem. Qhov tsis zoo ntawm lub laser semiconductor yog qhov kev ua tau zoo ntawm laser cuam tshuam los ntawm qhov kub thiab txias, thiab qhov sib txawv ntawm lub kaum sab xis ntawm lub nqaj loj (feem ntau ntawm ob peb degrees thiab 20 degrees), yog li nws tsis zoo rau kev coj ncaj ncees, cov cuab yeej monochromatic, thiab kev sib koom ua ke. Tab sis nrog txoj kev loj hlob sai ntawm kev tshawb fawb thiab thev naus laus zis, kev tshawb fawb ntawm dpss lasers tau nce mus rau qhov kev coj ntawm qhov tob, thiab kev ua haujlwm ntawm semiconductor laser yog niaj hnub txhim kho. Semiconductor optoelectronics thev naus laus zis nrog semiconductor laser raws li cov tub ntxhais yuav ua rau muaj kev vam meej thiab ua lub luag haujlwm ntau dua hauv cov ntaub ntawv hauv zej zog ntawm lub xyoo pua 21st.

2. Ua hauj lwm hauv paus ntsiab lus ntawm semiconductor lasers

Lub semiconductor laser yog ib qho hluav taws xob sib txuas. Peb cov xwm txheej yooj yim yuav tsum tau ua kom thiaj li tsim tau lub laser.

① Tau txais qhov xwm txheej: qhov kev faib tawm ntawm cov neeg nqa khoom thauj hauv qhov nruab nrab excitation (chaw ua haujlwm) tau tsim. Nyob rau hauv semiconductors, lub zog ntawm electrons yog sawv cev los ntawm ib tug series ntawm ze li ntawm tas mus li zog theem. Qhov no yog ua tiav los ntawm kev siv qhov kev tsis ncaj ncees rau pem hauv ntej mus rau homogeneous lossis heterojunction thiab txhaj cov khoom tsim nyog rau hauv cov txheej txheem kom ua kom cov electrons los ntawm qis valence band mus rau qhov siab dua conduction band. Stimulated emission tshwm sim thaum muaj coob tus electrons nyob rau hauv lub reversed particle pej xeem xeev recombine nrog qhov.

② kom tau txais cov hluav taws xob zoo sib xws, ib qho yuav tsum ua kom cov hluav taws xob zoo siab hauv qhov kho qhov muag resonator kom tau txais ntau lub tswv yim thiab daim ntawv laser oscillation, lub resonator ntawm lub laser yog tsim los ntawm lub ntuj cleavage nto ntawm lub semiconductor siv lead ua iav, feem ntau nyob rau hauv lub kawg. ntawm lub teeb plating ntawm lub siab inverse multilayer dielectric zaj duab xis, thiab tus nto plating ntawm cov yeeb yaj kiab txo qis. Rau Fp kab noj hniav (Fabry-Perot kab noj hniav) semiconductor laser, FP kab noj hniav yuav yooj yim tsim los ntawm lub ntuj cleavage dav hlau perpendicular mus rau pn hlws ris dav hlau ntawm cov siv lead ua.

③ Txhawm rau tsim kom muaj zog oscillation, lub laser nruab nrab yuav tsum muaj peev xwm ua kom tau txais txiaj ntsig txaus los ua rau qhov poob ntawm qhov muag pom los ntawm cov kab noj hniav resonant thiab cov laser tso tawm los ntawm qhov chaw ntawm kab noj hniav, thiab tas li nce qhov kho qhov muag hauv kab noj hniav. Qhov no yuav tsum tau muaj zog txaus tam sim no txhaj tshuaj, uas yog, txaus particle tooj inversion. Qhov siab dua qhov kev hloov pauv ntawm tus lej particle ntau dua, qhov nce ntau dua, uas yog, qee qhov xwm txheej tam sim no yuav tsum tau ntsib. Thaum lub laser ncav cuag qhov pib, lub teeb nrog ib lub wavelength tshwj xeeb tuaj yeem ua rau hauv cov kab noj hniav thiab ua kom nrov, thiab thaum kawg tsim lub laser thiab tso tawm tsis tu ncua. Nws tuaj yeem pom tau tias kev hloov pauv ntawm dipole ntawm electron thiab qhov yog cov txheej txheem ntawm lub teeb emission thiab lub teeb amplification hauv semiconductor lasers. Rau qhov tshiab semiconductor laser, nws feem ntau lees txais tias quantum zoo yog lub hauv paus tsav tsheb rau kev loj hlob ntawm lasers. Cov lus nug e ntawm seb quantum xov hlau thiab cov dots tuaj yeem ua kom zoo dua ntawm cov teebmeem quantum tau txuas ntxiv mus rau xyoo pua no. Cov kws tshawb fawb tau sim nrog tus kheej tsim qauv los ua quantum dots nyob rau hauv ntau yam ntaub ntawv, thiab GaInN quantum dots tau siv nyob rau hauv semiconductor lasers.

Hloov mus rau partⅡ nkag siab txog nws keeb kwm thiab daim ntawv thov

Cov ntaub ntawv tiv tauj:

Yog tias koj muaj lus nug, thov hu rau peb. Txawm peb cov neeg muas zaub nyob qhov twg thiab peb cov kev xav tau yog dab tsi, peb yuav ua raws li peb lub hom phiaj los muab peb cov neeg siv khoom zoo, tus nqi qis, thiab kev pabcuam zoo tshaj plaws.