Semiconductor lasers yog quantum generators raws li ib tug semiconductor active nruab nrab nyob rau hauv uas optical amplification yog tsim los ntawm stimulated emission thaum lub sij hawm ib tug quantum hloov ntawm lub zog theem ntawm ib tug siab concentration ntawm tus nqi thauj khoom nyob rau hauv lub free zone.
Semiconductor laser: txoj cai ntawm kev ua haujlwm
Nyob rau hauv lub xeev ib txwm, feem ntau cov electrons nyob rau ntawm valency theem. Thaum photons muab lub zog ntau tshaj lub zog ntawm qhov tsis sib xws, cov electrons ntawm lub semiconductor tuaj rau hauv lub xeev ntawm excitation thiab, tau kov yeej qhov txwv tsis pub, hla mus rau hauv thaj chaw dawb, tsom rau ntawm nws sab ntug. Nyob rau tib lub sijhawm, cov qhov tsim nyob rau theem valence nce mus rau nws thaj tsam sab saud. Electrons nyob rau hauv thaj chaw dawb recombine nrog lub qhov, radiating lub zog sib npaug zos rau lub zog ntawm lub discontinuity cheeb tsam nyob rau hauv daim ntawv ntawm photons. Recombination tuaj yeem txhim kho los ntawm photons nrog cov qib zog txaus. Cov lus piav qhia tus lej sib raug rau Fermi kev faib ua haujlwm.
Device
Semiconductor laser ntaus ntawvyog lub laser diode pumped nrog lub zog ntawm electrons thiab qhov nyob rau hauv p-n-hluav taws xob cheeb tsam - lub point ntawm kev sib cuag ntawm semiconductors nrog p- thiab n-hom conductivity. Tsis tas li ntawd, muaj semiconductor lasers nrog optical zog mov, nyob rau hauv uas lub beam yog tsim los ntawm absorbing photons ntawm lub teeb, raws li zoo raws li quantum cascade lasers, uas nws ua hauj lwm yog raws li nyob rau hauv cov kev hloov nyob rau hauv bands.
Composition
qauv kev sib txuas siv hauv ob qho tib si semiconductor lasers thiab lwm yam khoom siv optoelectronic yog raws li hauv qab no:
- galium arsenide;
- galium phosphide;
- galium nitride;
- indium phosphide;
- indium-galium arsenide;
- galium aluminium arsenide;
- gallium-indium arsenide nitride;
- gallium-indium phosphide.
wavelength
Cov tebchaw no yog direct-gap semiconductors. Indirect-gap (silicon) lub teeb tsis tawm nrog lub zog txaus thiab kev ua haujlwm zoo. Lub wavelength ntawm lub diode laser hluav taws xob nyob ntawm qhov degree ntawm approximation ntawm photon zog mus rau lub zog ntawm lub discontinuity cheeb tsam ntawm ib tug tej compound. Hauv 3- thiab 4-cov khoom sib txuas semiconductor, lub zog tsis sib xws tuaj yeem sib txawv ntawm ntau yam. Rau AlGaAs=AlxGa1-xAs, piv txwv li, kev nce hauv cov ntsiab lus ntawm txhuas (nce hauv x) ua rau muaj kev nce hauv lub zog ntawm thaj tsam tsis sib xws.
Thaum cov lasers feem ntau siv nyob rau hauv qhov ze infrared, qee qhov emit liab (indium gallium phosphide), xiav lossis violet (gallium nitride) xim. Mid-infrared tawg yog tsim los ntawm semiconductor lasers (lead selenide) thiab quantum cascade lasers.
YOrganic semiconductors
Ntxiv rau cov lus hais saum toj no, cov organic kuj tseem siv tau. Cov cuab yeej sib raug zoo tseem tab tom txhim kho, tab sis nws txoj kev loj hlob tau cog lus tias yuav txo tau tus nqi ntawm cov quantum generators. Txog tam sim no, tsuas yog cov organic lasers nrog cov khoom siv kho qhov muag tau tsim, thiab kev siv hluav taws xob tau zoo heev tseem tsis tau ua tiav.
Ntau yam
Ntau lub tshuab hluav taws xob semiconductor tau tsim, sib txawv ntawm qhov ntsuas thiab siv tus nqi.
Me me laser diodes tsim cov kab hluav taws xob zoo ntawm ntug hluav taws xob, lub zog ntawm ntau yam ntawm ntau txog tsib puas milliwatts. Lub laser diode siv lead ua yog ib lub phaj nyias nyias uas ua hauj lwm raws li ib tug waveguide, vim hais tias cov hluav taws xob yog txwv rau ib qho chaw me me. Cov siv lead ua yog doped rau ntawm ob sab los tsim ib qho kev sib tshuam p-n ntawm thaj chaw loj. Cov polished kawg tsim ib qho kev kho qhov muag Fabry-Perot resonator. Ib tug photon dhau los ntawm lub resonator yuav ua rau recombination, hluav taws xob yuav nce, thiab tiam yuav pib. Siv nyob rau hauv laser pointers, CD thiab DVD players, thiab fiber optic kev sib txuas lus.
Lub zog qis monolithic lasers thiab quantum generators nrog rau sab nraud resonator los ua cov pulses luv luv tuaj yeem tsim hom xauv.
Lasersemiconductor nrog ib tug sab nraud resonator muaj xws li ib tug laser diode, uas plays lub luag hauj lwm ntawm ib tug amplifying nruab nrab nyob rau hauv muaj pes tsawg leeg ntawm ib tug loj laser resonator. Lawv muaj peev xwm hloov lub wavelengths thiab muaj ib tug nqaim emission band.
Txhaj tshuaj semiconductor lasers muaj thaj tsam emission nyob rau hauv daim ntawv ntawm ib tug dav band, muaj peev xwm tsim tau ib tug zoo beam nrog lub hwj chim ntawm ob peb watts. Lawv muaj cov txheej nyias nyias nyob nruab nrab ntawm p- thiab n-txheej, ua rau ob lub heterojunction. Tsis muaj lub tshuab ua kom lub teeb nyob rau sab nraud, uas ua rau lub teeb pom kev siab ellipticity thiab tsis tuaj yeem lees txais qhov ntsuas kub tam sim no.
Lub zog diode tuav, suav nrog array ntawm broadband diodes, muaj peev xwm ua tau ib lub teeb ntawm nruab nrab zoo nrog lub zog ntawm kaum tawm watts.
Lub zog muaj zog ob sab ntawm diodes tuaj yeem tsim lub zog hauv ntau pua thiab txhiab watts.
Nto emitting lasers (VCSELs) emit ib lub teeb zoo ntawm lub teeb nrog lub zog ntawm ob peb milliwatts perpendicular rau lub phaj. Cov iav resonator yog siv rau ntawm cov hluav taws xob nyob rau hauv daim ntawv ntawm cov khaubncaws sab nraud povtseg ntawm ¼ nthwv dej ntev nrog qhov sib txawv refractive indices. Ob peb puas lasers tuaj yeem ua rau ntawm ib nti, uas qhib qhov ua tau ntawm ntau lawm.
VECSEL lasers nrog optical fais fab mov thiab ib lub resonator sab nraud muaj peev xwm tsim tau ib tug nqaj ntawm zoo zoo nrog lub hwj chim ntawm ob peb watts nyob rau hauv hom xauv.
Kev ua haujlwm ntawm semiconductor laser quantum-cascade hom yog raws li kev hloov pauv hauv cov cheeb tsam (raws li qhov tsis sib xws rau interzones). Cov khoom siv no tawm hauv thaj tsam nruab nrab-infrared, qee zaum hauv terahertz ntau yam. Lawv siv, piv txwv li, ua cov ntsuas roj.
Semiconductor lasers: daim ntawv thov thiab cov ntsiab lus
Powerful diode lasers nrog high-efficiency hluav taws xob twj ntawm nruab nrab voltages yog siv raws li ib tug txhais tau tias ntawm powering high-efficiency solid-state lasers.
Semiconductor lasers tuaj yeem ua haujlwm ntau zaus, uas suav nrog qhov pom, ze-infrared, thiab nruab nrab-infrared feem ntawm cov spectrum. Cov khoom siv tau raug tsim los uas tseem tso cai rau koj hloov qhov zaus ntawm emission.
Laser diodes tuaj yeem hloov pauv sai thiab hloov kho qhov muag lub zog, uas pom daim ntawv thov hauv fiber ntau optic transmitters.
Cov yam ntxwv zoo li no tau ua semiconductor lasers thev naus laus zis yog hom tseem ceeb tshaj plaws ntawm quantum generators. Lawv thov:
- hauv telemetry sensors, pyrometers, optical altimeters, rangefinders, pom, holography;
- hauv fiber ntau optic systems ntawm optical kis tau tus mob thiab cov ntaub ntawv cia, coherent kev sib txuas lus systems;
- hauv laser printers, video projectors, pointers, barcode scanners, duab scanners, CD player (DVD, CD, Blu-Ray);
- hauv kev ruaj ntseg, quantum cryptography, automation, ntsuas;
- hauv optical metrology thiab spectroscopy;
- hauv kev phais, kho hniav, cosmetology, kho;
- rau kev kho dej,Cov ntaub ntawv ua, cov khoom siv hauv lub xeev laser siv, tshuaj tiv thaiv tshuaj tiv thaiv, kev txheeb xyuas, kev lag luam engineering, ignition systems, cua tiv thaiv systems.
Pulse output
Feem ntau cov semiconductor lasers tsim ib lub teeb nruam. Vim lub sij hawm nyob luv luv ntawm electrons ntawm theem conduction, lawv tsis haum rau tsim Q-hloov pulses, tab sis lub quasi-nruam hom ntawm kev ua hauj lwm tso cai rau ib tug tseem ceeb nce nyob rau hauv lub hwj chim ntawm lub quantum generator. Tsis tas li ntawd, semiconductor lasers tuaj yeem siv los tsim cov pulses ultrashort nrog hom xauv lossis nce kev hloov pauv. Lub zog nruab nrab ntawm cov pulses luv luv feem ntau txwv rau ob peb milliwatts, tshwj tsis yog ntawm optically pumped VECSEL lasers, uas nws cov zis yog ntsuas los ntawm multi-watt picosecond pulses nrog ntau zaus ntawm kaum tawm gigahertz.
Modulation thiab stabilization
Qhov kom zoo dua ntawm kev nyob luv luv ntawm ib qho hluav taws xob hauv cov khoom siv hluav taws xob yog lub peev xwm ntawm semiconductor lasers rau high-frequency modulation, uas rau VCSEL lasers tshaj 10 GHz. Nws tau pom daim ntawv thov hauv kev xa cov ntaub ntawv kho qhov muag, spectroscopy, laser stabilization.
