Lasers tau dhau los ua cov cuab yeej tshawb fawb tseem ceeb hauv tshuaj, physics, chemistry, geology, biology thiab engineering. Yog tias siv tsis raug, lawv tuaj yeem ua rau dazzle thiab raug mob (xws li kub hnyiab thiab hluav taws xob poob siab) rau cov neeg ua haujlwm thiab lwm tus neeg ua haujlwm, suav nrog cov neeg tuaj saib hauv chav kuaj, thiab ua rau muaj kev puas tsuaj loj. Cov neeg siv ntawm cov cuab yeej no yuav tsum nkag siab thiab siv cov kev tiv thaiv kev nyab xeeb tsim nyog thaum tuav lawv.
YDab tsi yog laser?
Lo lus "laser" (eng. LASER, Lub Teeb Amplification los ntawm Stimulated Emission of Radiation) yog cov ntawv luv uas sawv cev rau "kev nthuav dav ntawm lub teeb los ntawm kev cuam tshuam hluav taws xob." Qhov zaus ntawm cov hluav taws xob tsim los ntawm lub laser yog nyob rau hauv lossis ze ntawm qhov pom ntawm electromagnetic spectrum. Lub zog tau nthuav dav mus rau lub xeev ntawm kev siv zog heev los ntawm cov txheej txheem hu ua "laser induced radiation".
Lo lus "kua hluav taws xob" feem ntau nkag siab yuam kevyuam kev, vim nws kuj yog siv los piav txog cov khoom siv hluav taws xob. Hauv cov ntsiab lus no, nws txhais tau tias kev hloov pauv ntawm lub zog. Lub zog yog thauj los ntawm ib qhov chaw mus rau lwm qhov los ntawm kev sib txuas, convection thiab hluav taws xob.
Muaj ntau hom lasers ua haujlwm nyob rau hauv ib puag ncig sib txawv. Gases (piv txwv li, argon los yog sib tov ntawm helium thiab neon), cov khoom siv lead ua (piv txwv li, ruby) los yog kua dyes yog siv los ua qhov nruab nrab ua haujlwm. Thaum lub zog nkag mus rau qhov chaw ua haujlwm, nws nkag mus rau hauv lub xeev zoo siab thiab tso tawm lub zog hauv daim ntawv ntawm lub teeb (photons).
Ib nkawm tsom iav ntawm ob qho kawg ntawm lub raj kaw yog qhov cuam tshuam los yog xa lub teeb hauv cov kwj deg hu ua laser beam. Txhua qhov chaw ua haujlwm tsim ib lub teeb ntawm qhov sib txawv wavelength thiab xim.
Cov xim ntawm lub teeb laser feem ntau qhia nyob rau hauv cov nqe lus ntawm wavelength. Nws yog non-ionizing thiab suav nrog ultraviolet (100-400 nm), pom (400-700 nm) thiab infrared (700 nm - 1 mm) ib feem ntawm spectrum.
YElectromagnetic spectrum
Txhua qhov hluav taws xob nthwv dej muaj qhov sib txawv thiab qhov ntev uas cuam tshuam nrog qhov ntsuas no. Ib yam li lub teeb liab muaj nws tus kheej zaus thiab wavelength, yog li tag nrho lwm cov xim - txiv kab ntxwv, daj, ntsuab thiab xiav - muaj cov cim zaus thiab wavelengths. Tib neeg muaj peev xwm pom tau cov hluav taws xob hluav taws xob, tab sis tsis tuaj yeem pom qhov seem ntawm qhov spectrum.
Gamma rays, X-rays thiab ultraviolet muaj qhov zaus tshaj plaws. infrared,microwave hluav taws xob thiab xov tooj cua nthwv dej nyob qis dua ntawm cov spectrum. Lub teeb pom kev nyob hauv qhov nqaim heev nyob nruab nrab ntawm.
Laser tawg: tib neeg raug
Lub laser ua rau lub teeb ci ntsa iab. Yog hais tias qhia, xav txog, los yog tsom rau ib yam khoom, lub nqaj yuav raug absorbed ib nrab, tsa qhov chaw thiab sab hauv qhov kub ntawm cov khoom, uas yuav ua rau cov khoom hloov los yog deform. Cov khoom zoo no, uas tau pom daim ntawv thov hauv kev phais laser thiab cov khoom siv, tuaj yeem ua rau tib neeg cov ntaub so ntswg txaus ntshai.
Ntxiv rau cov hluav taws xob, uas muaj cov thermal nyhuv ntawm cov ntaub so ntswg, laser hluav taws xob yog qhov txaus ntshai, ua rau cov nyhuv photochemical. Nws tus mob yog ib tug luv luv wavelength, i.e. lub ultraviolet los yog xiav ib feem ntawm lub spectrum. Cov cuab yeej siv niaj hnub no tsim hluav taws xob laser, qhov cuam tshuam rau tus neeg ntawm qhov tsawg kawg nkaus. Lub zog qis lasers tsis muaj lub zog txaus ua rau muaj kev phom sij, thiab lawv tsis ua rau muaj kev phom sij.
Tib neeg cov ntaub so ntswg rhiab heev rau lub zog, thiab nyob rau hauv qee qhov xwm txheej, hluav taws xob hluav taws xob, suav nrog hluav taws xob laser, tuaj yeem ua rau lub qhov muag thiab tawv nqaij puas. Cov kev tshawb fawb tau ua tiav ntawm theem pib ntawm kev puas tsuaj hluav taws xob.
Qhov muag hazard
Tib neeg qhov muag yog qhov raug mob ntau dua li ntawm daim tawv nqaij. Lub cornea (pob tshab sab pem hauv ntej ntawm lub qhov muag), tsis zoo li lub dermis, tsis muaj txheej txheej ntawm cov hlwb tuag uas tiv thaiv ib puag ncig cuam tshuam. laser thiab ultravioletcov hluav taws xob yog absorbed los ntawm cornea ntawm lub qhov muag, uas tuaj yeem ua mob rau nws. Kev raug mob yog nrog los ntawm edema ntawm lub epithelium thiab yaig, thiab nyob rau hauv kev raug mob hnyav - clouding ntawm lub anterior chamber.
Lub qhov muag ntawm lub qhov muag kuj tuaj yeem raug mob thaum nws raug ntau yam hluav taws xob laser - infrared thiab ultraviolet.
Qhov txaus ntshai tshaj plaws, txawm li cas los xij, yog qhov cuam tshuam ntawm lub laser ntawm lub retina hauv qhov pom ntawm qhov muag pom - los ntawm 400 nm (violet) txog 1400 nm (ze infrared). Nyob rau hauv cheeb tsam no ntawm lub spectrum, collimated beams tsom mus rau qhov chaw me me ntawm retina. Qhov tsis zoo tshaj qhov txawv ntawm qhov raug tshwm sim thaum lub qhov muag ntsia mus rau hauv qhov kev ncua deb thiab ib txoj kab ncaj nraim los yog reflected nkag mus rau hauv nws. Hauv qhov no, nws cov concentration ntawm retina nce mus txog 100,000 zaug.
Yog li, lub teeb pom kev nrog lub zog ntawm 10 mW / cm 2 ua rau ntawm retina nrog lub zog ntawm 1000 W / cm 2. Qhov no yog ntau tshaj qhov txaus los ua kev puas tsuaj. Yog hais tias lub qhov muag tsis ntsia mus rau hauv qhov kev ncua deb, los yog yog hais tias lub beam yog reflected los ntawm ib tug diffuse, uas tsis yog-daim iav nto, muaj zog hluav taws xob ntau yuav ua rau raug mob. Cov nyhuv laser ntawm daim tawv nqaij tsis muaj qhov cuam tshuam, yog li nws tsis tshua muaj kev raug mob ntawm cov wavelengths.
X-rays
Qee lub tshuab hluav taws xob siab nrog qhov hluav taws xob siab dua 15 kV tuaj yeem tsim X-rays ntawm lub zog tseem ceeb: laser hluav taws xob, uas qhov chaw muaj hluav taws xob hluav taws xob siab-tso tawm excimer lasers, nrog rauplasma systems thiab ion qhov chaw. Cov cuab yeej no yuav tsum raug kuaj kom muaj kev nyab xeeb hluav taws xob, suav nrog kom muaj kev tiv thaiv kom raug.
Kev faib tawm
Nyob ntawm lub zog lossis lub zog ntawm cov nqaj thiab lub wavelength ntawm cov hluav taws xob, lasers tau muab faib ua ob peb chav kawm. Kev faib tawm yog nyob ntawm qhov muaj peev xwm rau cov cuab yeej ua rau raug mob tam sim ntawd rau lub qhov muag, tawv nqaij, lossis hluav taws kub thaum raug ncaj qha rau ntawm lub nqaj lossis thaum cuam tshuam los ntawm diffuse reflective nto. Tag nrho cov lag luam lasers raug txheeb xyuas los ntawm cov cim siv rau lawv. Yog hais tias lub cuab yeej yog hauv tsev los yog tsis muaj lwm yam cim, cov lus qhia yuav tsum tau nrhiav rau qhov tsim nyog kev faib tawm thiab daim ntawv lo. Lasers yog txawv los ntawm lub zog, wavelength thiab raug lub sij hawm.
Safe Devices
Cov khoom siv thawj zaug tsim cov hluav taws xob siv hluav taws xob tsawg. Nws tsis tuaj yeem ncav cuag qhov txaus ntshai, yog li cov peev txheej raug zam los ntawm kev tswj hwm feem ntau lossis lwm hom kev soj ntsuam. Piv txwv li: laser printers thiab CD player.
Cov khoom siv muaj kev nyab xeeb
Lasers ntawm chav kawm thib ob tawm hauv qhov pom ntawm qhov spectrum. Qhov no yog laser hluav taws xob, qhov chaw uas ua rau ib tug neeg muaj ib txwm cov tshuaj tiv thaiv ntawm rejection ntawm lub teeb ci dhau lawm (blink reflex). Thaum raug cov nqaj, tib neeg lub qhov muag blinks tom qab 0.25 s, uas muab kev tiv thaiv txaus. Txawm li cas los xij, laser hluav taws xob nyob rau hauv qhov pom ntau yam tuaj yeem ua rau lub qhov muag puas tsuaj tas li. Piv txwv li: laser pointers, geodetic lasers.
Class 2a lasers yog cov khoom siv tshwj xeeb uas muaj lub zog tso zis tsawg dua 1mW. Cov khoom siv no tsuas yog ua rau muaj kev puas tsuaj thaum raug ncaj qha rau ntau tshaj 1000 s hauv 8-teev hnub ua haujlwm. Piv txwv: tus nyeem ntawv barcode.
YDangerous lasers
Class 3a yog hais txog cov khoom siv uas tsis raug mob nrog lub sijhawm luv luv rau lub qhov muag uas tsis muaj kev tiv thaiv. Tej zaum yuav muaj kev phom sij thaum siv tsom iav tsom iav xws li telescopes, microscopes lossis binoculars. Piv txwv li: 1-5 mW He-Ne laser, qee lub laser pointers thiab lub tsev theem.
Class 3b laser beam tuaj yeem ua rau raug mob yog tias siv ncaj qha lossis cuam tshuam rov qab. Piv txwv li: 5-500mW HeNe laser, ntau kev tshawb fawb thiab kho lasers.
Class 4 suav nrog cov cuab yeej siv hluav taws xob ntau dua 500 mW. Lawv yog cov txaus ntshai rau lub qhov muag, tawv nqaij, thiab kuj yog hluav taws kub. Kev cuam tshuam rau ntawm lub nqaj, nws qhov kev xav tsis meej lossis nthuav dav tuaj yeem ua rau qhov muag thiab tawv nqaij raug mob. Txhua yam kev ruaj ntseg yuav tsum tau ua. Piv txwv li: Nd:YAG lasers, qhia, phais, hlau txiav.
Laser tawg: tiv thaiv
Txhua chav kuaj yuav tsum muaj kev tiv thaiv txaus rau cov neeg ua haujlwm nrog lasers. Qhov rais ntawm cov chav uas hluav taws xob los ntawm cov khoom siv ntawm chav kawm 2, 3 lossis 4 tuaj yeem dhau mus, ua rau muaj kev phom sijCov chaw tsis muaj kev tswj hwm yuav tsum tau them lossis tiv thaiv lwm yam thaum lub sijhawm ua haujlwm ntawm cov cuab yeej zoo li no. Txhawm rau tiv thaiv qhov muag ntau tshaj plaws, cov hauv qab no raug pom zoo.
- Lub nqaj yuav tsum tau muab ntim rau hauv qhov tsis muaj qhov cuam tshuam, tsis muaj hluav taws xob tiv thaiv los tiv thaiv kev pheej hmoo ntawm kev sib tsoo lossis hluav taws. Txhawm rau kho cov kab teeb, siv cov ntxaij vab tshaus fluorescent lossis lwm qhov pom; Tsis txhob ntsib qhov muag ncaj qha.
- Siv lub hwj chim qis tshaj plaws rau cov txheej txheem kev sib txuas ntawm kab. Yog tias ua tau, siv cov khoom siv qis kawg rau cov txheej txheem ua ntej sib dhos. Zam kom tsis txhob muaj cov khoom siv hluav taws xob tsis tsim nyog hauv cheeb tsam laser.
- txwv kev hla ntawm kab teeb hauv thaj chaw txaus ntshai thaum lub sijhawm tsis ua haujlwm, siv lub kaw lus thiab lwm yam teeb meem. Tsis txhob siv cov phab ntsa ntawm chav tsev los ua kom cov nqaj ntawm chav kawm 3b thiab 4 lasers.
- Siv cov cuab yeej tsis cuam tshuam. Qee cov khoom lag luam uas tsis muaj kev cuam tshuam pom lub teeb ua qhov pom tseeb hauv thaj tsam tsis pom ntawm cov spectrum.
- Tsis txhob hnav cov hniav nyiaj hniav kub. Cov hniav nyiaj hniav kub kuj ua rau muaj kev pheej hmoo ntawm hluav taws xob poob.
Goggles
Thaum ua haujlwm nrog Chav Kawm 4 lasers nrog thaj chaw muaj kev nyab xeeb qhib lossis qhov chaw muaj kev pheej hmoo ntawm kev xav, yuav tsum hnav looj tsom iav dub. Lawv hom nyob ntawm hom hluav taws xob. Cov tsom iav yuav tsum raug xaiv los tiv thaiv kev cuam tshuam, tshwj xeeb tshaj yog diffuse reflections, thiab muab kev tiv thaiv mus rau theem uas ntuj tiv thaiv reflex tuaj yeem tiv thaiv qhov muag raug mob. Xws li cov khoom siv kho qhov muagtuav qee qhov pom ntawm cov nqaj, tiv thaiv cov tawv nqaij kub hnyiab, txo qhov muaj peev xwm ntawm lwm yam xwm txheej.
Yam yuav tsum xav txog thaum xaiv tsom iav:
- wavelength lossis cheeb tsam ntawm cov hluav taws xob spectrum;
- kho qhov muag ceev ntawm ib lub wavelength tshwj xeeb;
- siab tshaj qhov pom kev (W / cm2) lossis nqaj zog (W);
- laser system hom;
- hom fais fab - mem tes laser teeb lossis hom txuas ntxiv;
- muaj peev xwm rov qab xav - specular thiab diffuse;
- teb saib;
- muaj cov lo ntsiab muag kho lossis qhov loj txaus kom tso cai hnav cov tsom iav kho;
- xov xwm;
- muaj lub qhov cua kom tiv thaiv kom tsis txhob yaig;
- cuam tshuam rau qhov pom xim;
- cuam tshuam;
- muaj peev xwm ua tau haujlwm tsim nyog.
Vim tias cov tsom iav kev nyab xeeb muaj qhov cuam tshuam rau kev puas tsuaj thiab hnav, lub chaw kuaj xyuas kev nyab xeeb yuav tsum suav nrog cov kev kuaj xyuas raws sij hawm ntawm cov yam ntxwv tiv thaiv no.
