laser diode txhais tau li cas?
LASER yog ib hom teeb pom kev tsim tawm xyoo 1960.LASER yog cov ntawv siv rau" lub zog tawm ntawm lub teeb ua kom nrov" hauv Lus Askiv. Muaj ntau yam ntawm lasers, uas yog loj rau ob peb thaj chaw ncaws pob thiab me me mus rau ib cov nplej los yog cov ntsev.Qhov roj laser muaj helium-neon laser thiab argon laser; Lub teeb-rau laser muaj lub ruby laser; Semiconductor lasers muaj laser diodes, xws li cov uas nyob hauv CD players, DVD players thiab cd-roms.Each laser muaj nws tus kheej tshwj xeeb txoj kev tsim cov teeb laser.Lasers muaj ntau lub zog: thawj, lasers yog monochrome, lossis ib-zaus.Yog muaj lasers uas tuaj yeem tsim cov ntau zaus tib lub sijhawm, tab sis cov lasers raug rho tawm thiab siv sib cais.Qhov tseeb, lasers yog lub teeb sib xws.Qhov yam ntxwv ntawm lub teeb ua ke yog tias txhua yam ntawm nws lub teeb tsis sib haum, thiab tag nrho cov nqaj zoo ib yam li" wave tsheb ciav hlau"
Cov kev tawm ntawm lub tshuab hluav taws xob (semiconductor) pom tau los ntawm kev txhaj tshuaj ntawm PN hlws ris.Nws muaj cov yam ntxwv ntawm cov khoom siv hluav taws xob: cov ntim me me, cov qauv yooj yim, kev ua haujlwm siab thiab kev hloov kho ncaj qha, tab sis cov zis muaj zog, monochromicity thiab kev taw qhia tsis zoo li lwm cov lasers.
Lub peb lub Cheebtsam ntawm lub tsa emission yog: laser khoom, particle tooj inversion faib thiab resonant cavity.Only direct bandgap semiconductor ntaub ntawv yuav ua laser diode, xws li Ⅲ - Ⅴ compound semiconductor (GaAs, InP, thiab lwm yam) thiab nws cov peb yuan, plaub yuan cov khoom siv daws teeb meem (Ga1 xAlxAs, In1 - xGaxAs1 yPy, thiab lwm yam), Ⅵ - Ⅵ cov khoom sib xyaw ua ke (Pb1 - xSnxTe, thiab lwm yam.) Tom qab ib leeg siv lead ua kev qhia, txiav thiab polishing, PN kev sib tshuam yog ua rau ntawm tej yam siv lead ua nto xws li (001) los ntawm diffusion los yog ntau txoj kev qhia epitaxial lossis cov tshuaj vapor deposition.
Nyob rau hauv lub caij nplooj zeeg ntawm 1962, lub homojunction GaAs laser diode ntawm lub pulsed mem tes nyob rau hauv 77K yog thawj developed.In 1964 nws ua hauj lwm kub twb tsa mus rau chav tsev temperature.In 1969, muaj ib zaug xwb heterojunction laser diode, uas ua pulses ntawm chav tsev kub, twb ua nyob rau xyoo 1970 los ua kev ua haujlwm tsis tu ncua ntawm ga1-xalxas / GaAs ob chav heterojunction (DH) laser diode.Vim li ntawd, laser diode tau tsim kho sai.Qhov lub neej ntawm Ga1-xAlxAs / GaAsDH laser diode nce mus txog ntau dua 105 teev hauv xyoo 1975. Qhov in1-xgaxas1-ypy / InP ntev ntev ntev ntev laser laser diode kuj ua rau muaj kev txhim kho tseem ceeb, yog li txhawb txoj kev loj hlob ntawm kev sib txuas lus fiber ntau thiab lwm yam kev siv.Yog li los ntawm Pb1 xSnxTe Ⅳ - Ⅵ cov ntaub ntawv xws li deb deb infrared wavelength laser diode.
Hauv cov kev taw qhia ntawm PN kev sib tshuam, muaj cov txheej txheem homogeneous, ib qho kev sib txig sib luag, ob txoj kab sib chaws, feem ntau txwv, cov kab noj hniav loj thiab yog li on.Do lub tog hauv PN hlauv dav hlau qauv (piv txwv li, electrode bar, tiaj tus bar, protons rau hauv bar bar, bar groove substrate, cov kauj ruam, faus kab rov tav bar, bar, compression bar, thiab lwm yam.) Lub resonator yog nyob rau hauv daim ntawv ntawm fabry-perot kab noj hniav, cov lus qhia faib tawm thiab Bragg reflection.With txawv semiconductor heterostructure lattice mismatch, siv lawv hauv cov txwv tsis pub dav thiab qhov sib txawv ntawm qhov ntsuas refractive, tuaj yeem tau txais yuav luag tag nrho ntawm qhov kev taw qhia ntsug ntawm pn kev sib tshuam ntawm cov cab kuj qhov kev txwv thiab qhov pom kev tsis zoo.Qhov ntau yam ntawm cov kab txuas rau cov kev taw qhia kev sib txuas siab tuaj yeem tsom mus rau tam sim no ntawm thaj chaw nqaim thiab muab qhov nce waveguide lossis refractive index waveguide.Qhov kev teeb tsa txhim kho tau zoo heev ua tiav ntawm kev ua haujlwm ntawm lub laser diode.
Laser diode yog qhov tseem ceeb semiconductor diode, raws li qhov kev sib tshuam pn yog cov khoom siv tib yam, tuaj yeem muab faib ua homogeneous lub laser diode hlws ris, ib leeg heterojunction (SH), ob chav heterostructure (DH) thiab quantum zoo (GG # 39; ve) laser. diode.Quantum zoo laser diode muaj qhov zoo ntawm kev pib qis tam sim no thiab cov zis hluav taws xob siab, uas yog cov khoom tseem ceeb ntawm cov ntawv thov kev lag luam tam sim no.
Piv nrog rau laser, laser diode muaj zoo ntawm high efficiency, me me volume, ntev kev pab cuam lub neej, tab sis nws tso zis ntau zog yog me me (feem ntau tsawg tshaj li 2 MW), linear, cov neeg pluag monochromaticity, zoo heev, ua rau nws muaj kev txwv rau hauv daim ntawv thov ntawm cable TV system, yuav tsis kis multi-channel, muaj kev kawm siab analog signals.In ncha module ntawm bidirectional kho qhov muag receiver, ib tug quantum zoo laser diode yog siv raws li lub teeb qhov chaw.
Cov qauv ntawm laser diode
Cov qauv thiab cim ntawm lub laser diode yog muaj nyob hauv daim duab 1.
Lub cev qauv ntawm laser diode yog nyob rau hauv lub teeb emitting diode hlws ris tso ib txheej ntawm lub teeb nruab nrab ntawm cov kev ua ntawm semiconductor thiab nws qhov kawg tom qab polishing muaj qee qhov cuam tshuam muaj nuj nqi, yog li tsim qhov kho qhov muag resonator.Qhov teeb meem ntawm qhov tsis zoo, LED DE facto radiates teeb thiab thiab cuam tshuam nrog kev kho qhov muag kom zoo, yog li ntxiv cov kev txhawb zog ib lub teeb ntawm lub teeb uas tawm ntawm cov kev sib tshuam ntawm lub cev lub cev muaj feem cuam tshuam nrog cov khoom ntawm hom teeb no.
Kev ua haujlwm ntawm kev ua haujlwm ntawm semiconductor laser diode yog qhov zoo ib yam li cov pa roj laser.Figure 1 (b) yog lub cim ntawm lub laser diode.Qhov laser diode siv nyob rau hauv optical disk tsav ntawm lub computer, thiab luam tawm thawj chav kawm cov khoom siv fais fab photoelectric me me hauv lub tshuab luam ntawv laser tau dav siv.
Laser diode qauv duab kos duab thiab cim
Tej yam yooj yim hauv paus ntsiab lus ntawm laser diode
Lub teeb hluav taws xob hauv cov khoom hluav taws xob feem ntau tshwm sim los ntawm qhov sib xyaw ntawm cov khoom thauj.Thaum ntxiv nrog cov hluav taws xob zoo semiconductor PN kev sib tshuam, tsis muaj zog pn kev sib tshuam, yuam cov hluav taws xob los ntawm kev txhaj tshuaj rau cheeb tsam PN los ntawm thaj chaw PN, qhov ntawm P cheeb tsam mus rau N tom qab thaj chaw PN, nyob ze ntawm kev txhaj tshuaj ntawm pn hlws ris tsis sib txig cov hluav taws xob thiab qhov yuav tshwm sim sib xyaw, yog li emitting wavelength rau lambda photons, nws cov mis yog li hauv qab no:
Lambda=hc / Eg (1)
Hauv cov qauv: h - Planck tas mus li; C - qhov nrawm nrawm; Eg - band dav ntawm ib nrab xov.
Qhov no tshwm sim yog hu ua txawj tawg vim lub txawj recombination ntawm electrons thiab holes.When photons ua los ntawm txawj tawg los ntawm semiconductor, ib zaug tom qab lub community launch txog lub tshuab hluav taws xob - qhov ze, muaj peev xwm txhawb cov miv sab lub compound, los ua kom muaj tshiab photons, lub photon ntxias muaj kev tshoov siab cov cab kuj sib xyaw thiab cov photon tshiab yog hu ua lub teeb tsa hluav taws xob.Yog hais tias qhov kev txhaj tshuaj tam sim no loj txaus, qhov faib cov khoom xa tuaj, uas yog qhov rov qab ntawm lub thermal equilibrium hauv lub xeev, yog qhov rov qab ntawm tus naj npawb ntawm cov khoom.Peb cov cab kuj ntawm cov nquag txheej nyob rau hauv cov ntaub ntawv ntawm ib tug loj tus naj npawb ntawm inversion, ib tug me me npaum li cas ntawm photons ua los ntawm cov txawj tawg ntxias los ntawm ob transverse reciprocating thiaj kab noj hniav tawg, zaus xim resonance tshwm sim los ntawm lub zoo tswv yim, los yog muaj ib tug nce nyob rau hauv ib tug tej yam frequency.When lub nce loj dua qhov kev poob zoo, qhov teeb ci ntsa iab los ntawm kev sib tshuam PN tuaj yeem tawm nrog cov kab zoo spectral - laser, uas yog qhov yooj yim hauv paus ntsiab lus ntawm cov laser diode.
Nrog rau kev txhim kho thev naus laus zis, qhov tam sim no siv hluav taws xob semiconductor laser diode muaj cov qauv ntau txheej txheej.Figure 2 yog cov qauv ntawm lub teeb liab semiconductor laser diode ntawm sanyo tuam txhab hauv Nyiv.FIG. 3 yog lub hwj chim me me laser lub raj xa khoom saib. Nws tuaj yeem pom tias cov laser nti txuas nrog lub dab dej siv hluav taws xob siv rau cov cua sov kom sov. Tus PIN photodiode txuas rau hauv ntu qis ntawm lub raj tub ze ntawm lub laser nti.Figure 4 rau qhov zoo li zoo tib yam laser diode, daim duab qhia, lub zog me me laser lub raj muaj peb koob, qhov no vim tias lub raj kuj encapsulate ib photodiode, ua hauj lwm tam sim no yog siv los mus saib xyuas lub laser raj.