Laser zaus ob npaug yog dab tsi?

Yog dab tsilaser zaus ob npaug?
Yuav luag txhua tus neeg uas koom nrog kev tshawb fawb thiab kev txhim kho laser, khoom siv, thiab kho qhov muag tau hnov ​​​​​​txog kev siv tshuab zaus ob npaug. Qhov xwm txheej feem ntau yog 1064nm infrared laser, uas hla dhau lub siv lead ua thiab ncaj qha hloov mus rau hauv lub teeb ntsuab 532nm. Muaj ntau tus neeg muaj lus nug hauv lawv lub siab: Puas yog txhua qhov luminescence tshwm sim los ntawm electron qhov recombination thiab tso tawm ntawm bandgap zog?
1, Qhov tshwm sim ntawm kev ua ob npaug: qhov zaus thiab lub zog ntawm lub teeb hloov pauv ntawm kev ua ob npaug
Tsis txhob tham txog cov qauv nyuaj, tsuas yog nco ntsoov cov kev sib raug zoo tseem ceeb tshaj plaws ntawm kev nkag mus thiab tso zis sai sai:
Teeb pom kev (lub teeb zaus tseem ceeb): zaus f, wavelength λ, lub zog photon ib leeg E
Lub teeb tawm (ob lub teeb zaus): zaus 2f, wavelength λ/2, lub zog photon ib leeg 2E
Cov ntaub ntawv classic tshaj plaws:
1064nm infrared laser→ zaus ob npaug → 532nm lub teeb ntsuab
Kev nkag siab yooj yim: Ob lub photons infrared uas muaj zaus tsawg, lub zog tsawg sib koom ua ke rau hauv ib lub photon ntsuab uas muaj zaus siab, lub zog siab.
Muaj ib qho xwm txheej uas tawm tsam kev paub txog ib txwm muaj tau tshwm sim ntawm no:
Kev ci ntsa iab ib txwm muaj: Lub zog photon tsuas yog tsawg dua lossis sib npaug rau lub zog excitation, ua rau poob zog;
Zaus ob npaug ntawm lub teeb ci: ncaj qha ua cov photons nrog lub zog ob npaug, tsis muaj kev koom tes ntawm kev hloov pauv bandgap.
2, Core Soul Interrogation: Vim li cas qhov zaus ob npaug ntawm luminescence tsis muaj feem cuam tshuam rau cov khoom siv bandgap?
Kev tshuaj xyuas zoo los ntawm qhov pom ntawm kev tshawb fawb txog cov ntaub ntawv:
Qhov sib txawv ntawm cov qhab yog qhov pib rau "kev hloov pauv hluav taws xob luminescence", thaum qhov zaus ob npaug yog qhov khoom ntawm "kev sib hloov pauv polarization muaj zog", uas tsis hla qhov sib txawv ntawm cov qhab, tsis rov ua ke, thiab tsis khaws lub zog thoob plaws hauv tag nrho cov txheej txheem.
2.1 Kev ci ntsa iab ib txwm muaj (nyob ntawm bandgap)
Lub ntsiab lus yog cov txheej txheem hloov pauv quantum: cov electrons yuav tsum nqus lub zog hla lub bandgap thiab tom qab ntawd poob rov qab los sib xyaw thiab tso tawm lub teeb.
Yog tsis muaj qhov bandgap sib xws, tsis muaj qhov wavelength emission sib xws, xauv tag nrho los ntawm cov khoom siv ntawm cov khoom siv.
2.2 Zaus ob npaug ntawm qhov ci ntsa iab (ywj siab ntawm bandgap)
Thaum cov siv lead ua ob npaug zaus (LBO, KTP, BBO, thiab lwm yam) ua haujlwm, lawv yuav luag tsis nqus cov xwm txheejlub teeb laser.
Tsis muaj kev hloov pauv ntawm electron, tsis muaj electron qhov recombination, thiab tsis muaj kev khaws cia zog.
Cov txheej txheem microscopic tiag tiag yog yooj yim heev: lub zog photoelectric ntawm lub laser muaj zog heev rub lub huab hluav taws xob sab nraud ntawm cov atoms siv lead ua ke. Nyob rau hauv lub teeb qis qis (hnub ci, lub teeb ib txwm muaj), cov huab hluav taws xob ua raws li lub teeb kom ua rau cov oscillations sinusoidal tas li, nrog cov waveforms ib txwm thiab tsis muaj cov zaus tshiab, uas yog linear optics. Nyob rau hauv lub zog laser siab heev, lub zog ntawm lub zog photoelectric yog muaj zog heev, thiab qhov oscillation ntawm cov huab hluav taws xob yog yuam "twisted thiab deformed", tsis yog ib qho sine wave txheem. Qhov distorted oscillation waveform no yuav faib ua ob qho oscillation Cheebtsam: "zaus thawj" thiab "zaus ob npaug". Qhov oscillation ob npaug ntawm cov electrons thiab cov nthwv dej electromagnetic radiated sab nraud hu ua ob npaug zaus teeb.
3, Tus yuam sij rau Kev Tshawb Fawb Txog Khoom Siv: Cov siv lead ua hom twg tuaj yeem ua ob npaug zaus?
Vim tias peb tsis saib qhov bandgap, peb yuav ua li cas los tshuaj xyuas cov siv lead ua ob npaug zaus? Lub hauv paus muaj ob qho xwm txheej, uas tsis yog nyob ntawm qhov bandgap:
3.1. Lub siv lead ua yuav tsum muaj "centrosymmetric structure", uas yog qhov rigid structural threshold rau frequency doubled. Yog tias lub siv lead ua yog ib qho centrally symmetric structure (xws li silicon, sodium chloride), qhov electron cloud rub deformation yuav symmetrically thiab raug tshem tawm, thiab distortion oscillation tsis tuaj yeem tsim tau, thiab frequency doubled yuav tsis ua tau.
3.2. Lub bandgap tsuas yog lub luag haujlwm rau "kev xa mus rau lub teeb hauv qab" thiab tsis txiav txim siab qhov wavelength ntawm emission. Lub luag haujlwm ntawm bandgap ntawm lub zaus ob npaug ntawm crystal yog kom ntseeg tau tias nws tsis nqus lub teeb. Tsuav yog lub bandgap ntawm lub crystal loj txaus, lub teeb zaus tseem ceeb thiab lub teeb harmonic tsim tawm yuav tsis raug nqus, yuav tsis ua rau muaj kev hloov pauv hluav taws xob, thiab yuav tsis ua rau muaj kev puas tsuaj thermal, thiab tuaj yeem ua tiav harmonic ob npaug li qub.
4, Ua kom meej meej: qhov sib txawv tseem ceeb ntawm ob lub tshuab luminescent
4.1. Qhov sib txawv ntawm cov kab sib xyaw ua ke ntawm lub teeb ci (linear optics)
✅ Nyob ntawm kev hloov pauv hluav taws xob thiab kev sib xyaw ua ke ntawm cov cab kuj
✅ Qhov wavelength yog txiav txim siab tshwj xeeb los ntawm bandgap ntawm cov khoom siv
✅ Yuav tsum nqus tau zog, muaj kev poob zog
✅ Txawm tias lub teeb ci ntsa iab npaum li cas los xij, nws yuav tsis hloov pauv qhov zaus ntawm lub teeb
4.2. Lub zog laser ob npaug ntawm lub teeb ci (nonlinear optics)
✅ Kev co tsis sib xws ntawm cov huab cua electron los ntawm kev vam khom lub teeb ci ntsa iab
✅ Qhov zaus yog txiav txim siab los ntawm lub teeb pom kev thiab tsis yog nyob ntawm qhov sib txawv ntawm cov siv lead ua ke
✅ Tsis muaj kev nqus, tsis muaj kev hloov pauv, tsis muaj kev sib xyaw ua ke, tsis muaj kev khaws cia zog
✅ Tsuas yog lub zog laser ultrahigh tuaj yeem ua rau muaj kev phom sij
5. Cov lus xaus kawg ntawm kab lus kawg
Qhov sib txawv ntawm cov khoom siv yog lub qab nthab ntawm cov khoom siv uas nws tus kheej ci ntsa iab; Qhov zaus ob npaug yog tes khawv koob uas hloov cov nthwv dej teeb nrog lub teeb muaj zog. Peb txoj kev nkag siab ib txwm muaj txog kev ci ntsa iab yog tias cov khoom siv nws tus kheej tso tawm lub teeb; Kev siv tshuab ob npaug ntawm qhov zaus, ntawm qhov tod tes, cuam tshuam nrog kev sib tshooj ntawm lub teeb hauv lub siv lead ua los tsim lub teeb zaus siab tshiab, thiab tsis muaj dab tsi ua rau kev sib xyaw ua ke ntawm cov hluav taws xob hla qhov sib txawv.