Yuav ua li cas yog laser lub teeb? Laser tawg: nws qhov chaw thiab kev tiv thaiv los ntawm nws

Lasers yog ua nce tseem ceeb heev cov cuab yeej rau kev tshawb fawb nyob rau hauv lub teb ntawm cov tshuaj, physics, Science News for KIDS, geology, ib thiab technology. Yog hais tias siv tsis, lawv yuav tsum tau ua ntawv thov kom dig muag thiab raug mob (nyob rau hauv t. H. Burns thiab electrocution) tswv thiab lwm tus neeg, xws li xws li qhua Laboratories, raws li zoo raws li ua teeb meem loj cov vaj tse puas tsuaj. Cov neeg siv cov pab kiag li lawm yuav tsum nkag siab thiab siv cov tsim nyog muaj kev ruaj ntseg ceev faj thaum kov lawv.

Yuav ua li cas yog ib tug laser?

Lo lus "laser" (Engl. LASER, Lub teeb amplification los ntawm tsa Emission ntawm Tawg) yog ib qho acronym uas stands rau "lub teeb amplification tsa emission". Tus zaus ntawm hluav taws xob generated los ntawm laser yog nyob rau hauv los yog nyob ze ntawm lub pom ib feem ntawm lub electromagnetic spectrum. Zog yog kho kom zoo mus rau ib tug lub xeev uas tsis tshua muaj siab siv los ntawm ib tug txheej txheem uas hu ua "laser hob emission".

Lub sij hawm "tawg" yog feem ntau tsis to taub vim hais tias nws kuj yog siv nyob rau hauv qhov kev piav qhia ntawm tej ntaub ntawv. Nyob rau hauv qhov ntsiab lus teb, nws tau qhov kis tau tus mob ntawm lub zog. Zog yog kis los ntawm ib qhov chaw mus rau lwm lub los ntawm txoj kev conduction, convection thiab tawg.

Muaj ntau ntau ntau hom kev lasers kev khiav hauj lwm nyob rau hauv txawv kev kawm. Lub gases (e.g., argon los yog ib tug sib tov ntawm Helium thiab neon) yog siv raws li kev ua hauj lwm kua, khoom muaju (e.g. ruby) los yog kua colorants. Thaum lub hwj chim yog txhab khoom mus rau ua hauj lwm ib puag ncig, nws mus txog rau ib tug pog lub xeev thiab faib tawm zog nyob rau hauv daim ntawv ntawm lub teeb hais (photons).

Ib tug khub ntawm tsom iav ntawm ob hnub ntawm lub kaw raj yog qhia los yog hau lub teeb raws li ib tug concentrated kwj, hu ua lub laser beam. Txhua khiav hauj lwm cheeb tsam ua ib tug tshwj xeeb beam wavelength thiab xim.

Xim laser beam, feem ntau yog qhia wavelength. Nws yog uas tsis yog-ionizing thiab muaj xws li ultraviolet (100-400 nm), pom (400-700 nm) thiab infrared (700 nm - 1 hli) feem ntawm lub spectrum.

electromagnetic spectrum

Txhua muaj ib tug tshwj xeeb electromagnetic yoj zaus thiab ntev txuam nrog qhov kev xaiv no. Ib yam li lub teeb liab muaj nws tus kheej pes tsawg zaus thiab wavelength, thiab tag nrho cov lwm yam xim - txiv kab ntxwv, daj, ntsuab thiab xiav - nrog nws frequencies thiab wavelengths. Cov neeg siv yog tau perceive cov electromagnetic vuag, tab sis yog tsis tau pom tus so ntawm lub spectrum.

Qhov loj tshaj zaus yog gamma rays, X-rays thiab ultraviolet lub teeb. Infrared, microwave tawg thiab xov tooj cua tsis nyob rau sab frequencies ntawm lub spectrum. Pom lub teeb yog nyob rau hauv ib tug heev nqaim ntau therebetween.

Laser tawg: los ntawm cov tib neeg

Lub laser ua ib qho khaus teeb beam yog qhia. Yog hais tias nws yog rau pem hauv ntej, thaws rov los, los yog ua kom pom tseeb rau tus kwv, tus nqaj yog cov absorbed los ntawm raising tus nto kub thiab lub puab yog ib feem ntawm cov khoom uas yuav ua rau kev hloov los yog deformation ntawm cov khoom. Cov qualities uas tau siv nyob rau hauv laser phais thiab kev kho mob cov ntaub ntawv, muaj peev xwm yuav tej rau tib neeg cov ntaub so ntswg.

Nyob rau hauv tas li ntawd kom tawg, rendering lub thermal ntxim rau cov ntaub so ntswg txaus ntshai laser lub teeb, ua ib tug photochemical nyhuv. Nws mob yog sufficiently luv luv wavelength, ie. E. UV los yog xiav ib feem ntawm lub spectrum. Niaj hnub nimno pab kiag li lawm tsim laser emission, teebmeem rau tib neeg yog tsis tshua. Ntawm tsawg-zog laser yog tsis txaus yuav ua tau kom raug mob, thiab cov kev piam sij uas lawv teeb.

Tib neeg ntaub so ntswg yog rhiab zog, thiab nyob rau hauv tej yam tshwm sim hauv lub electromagnetic tawg, laser xws li, tej zaum yuav ua kev puas tsuaj rau lub qhov muag thiab tej tawv nqaij. kev ceeb toom txog kev puas tawg kev tshawb fawb tau tau ua.

Danger rau lub qhov muag

Cov tib neeg qhov muag yog raug rau kev raug mob tshaj ntawm daim tawv nqaij. Lub cornea (pob tshab txheej pem hauv ntej saum npoo ntawm lub qhov muag), nyob rau hauv sib piv rau lub dermis, muaj ib tug txheej txheej uas twb tuag lawm hlwb uas tiv thaiv ib puag ncig influences. Laser thiab ultraviolet tawg yog absorbed los ntawm lub cornea ntawm lub qhov muag uas muaj peev xwm ua kom muaj kev raug mob. Kev ceeb ntshai yog nrog los ntawm edema thiab epithelial yaig, thiab nyob rau hauv mob loj heev raug mob - clouding ntawm lub anterior chamber.

Lens ntawm lub qhov muag kuj yuav nws raug mob thaum nws yog raug rau ntau laser tawg - infrared thiab ultraviolet.

Qhov loj tshaj kev txaus ntshai, txawm li cas los, yog tej yam uas cov laser nyob rau retina nyob rau hauv qhov pom kho qhov muag spectrum - 400 nm (violet) rau 1400 nm (nyob ze infrared). Tsis pub dhau no cheeb tsam ntawm lub spectrum collimated beams yog teem rau ib tug heev me me qhov chaw ntawm lub retina. Phem tshaj cov ntaub raug tshwm sim thaum lub qhov muag zoo mus rau hauv cov kev coj thiab qhov ncaj los yog reflected beam hits nws. Nyob rau hauv cov ntaub ntawv no, nws concentration rau lub retina nce mus txog 100,000 lub sij hawm.

Yog li, ib tug pom beam ntawm 10 mW / cm ² ua rau lub retina nrog ib lub hwj chim ntawm 1000 W / ^cm2. Qhov no yog ntau tshaj li txaus kom ua rau kev puas tsuaj. Yog hais tias lub qhov muag yog tsis saib rau hauv qhov kev ncua deb, los yog yog hais tias tus nqaj yog reflected los ntawm ib tug diffuse, tsis rau hauv daim iav nto, ua rau yus raug mob yog ntau npaum li cas haib tawg. Lub laser nyhuv ntawm daim tawv nqaij devoid ntawm tsom nyhuv, ces nws yog ntau tsawg raug rau kev raug mob nyob rau hauv cov wavelengths.

X-rays

Ib txhia high-voltage nruab nrog voltages tshaj 15 kV yuav tsim X-rays ntawm loj hwj chim: lub laser lub teeb qhov chaw - ib tug haib excimer lasers nrog electron siv, raws li tau zoo raws li ntshav thiab ion qhov chaw hauv lub cev. Cov pab kiag li lawm yuav tsum tau soj ntsuam txog kev tawg kev nyab xeeb, xws li cov shielding.

kev faib

Nyob ntawm seb lub hwj chim los yog lub zog ntawm lub beam thiab lub wavelength ntawm cov tawg, lub lasers raug muab faib ua ob peb cov chav kawm ntawv. Cov kev faib yog raws li nyob rau hauv lub peev xwm ntawm lub ntaus ntawv mus rau ua tam sim ntawd raug mob rau lub qhov muag, tawv nqaij, o ntawm qhov ncaj raug mus rau lub beam los yog diffuse thiaj los ntawm paab chaw. Tag nrho cov coj mus muag lasers no yuav qhia kom paub los ntawm poob rau ntawm lawv daim ntawv. Yog hais tias tus ntaus ntawv yog manufactured tsev los yog lwm yam cim, tswv yim yuav tsum tau los ntawm coj mus rau nws cov kev faib thiab labeling. Lasers yog distinguished los ntawm lub hwj chim, wavelength thiab ntev ntawm raug.

Safety pab kiag li lawm

thawj chav kawm ntawv pab kiag li lawm tsim tsis muaj kev siv laser tawg. Nws yuav tsis tau ib tug txaus ntshai theem, ces tus qhov chaw yog raug zam los ntawm feem ntau tswj ntsuas los yog lwm yam ntaub ntawv ntawm cov kev soj ntsuam. Piv txwv li: laser printers thiab CD players.

Conditionally zoo ntaus ntawv

thib ob chav kawm lasers emit nyob rau hauv qhov pom spectrum. Qhov no laser lub teeb qhov chaw uas ua rau tib neeg ib txwm tshuaj tiv thaiv ntawm rejection yog ib yam nkaus thiab kaj lub teeb (tsuas ntsais muag lawm reflex). Thaum raug mus rau ib tug nqaj tib neeg qhov muag blinks 0.25 s, uas yuav muab txaus tiv thaiv. Txawm li cas los, lub laser tawg yog nyob rau hauv qhov pom ntau yam yuav ua mob rau lub qhov muag, qhov feem. Piv txwv: laser pointers, laser num.

2a-class lasers yog tshwj xeeb-lub hom phiaj pab kiag li lawm nrog tso zis ntau zog tsawg tshaj li 1 mW. Cov pab kiag li lawm ua rau kev puas tsuaj mus xwb lub feem tshaj 1000 rau ib tug 8-teev hnub ua hauj lwm. Piv txwv li kev nyeem ntawv barcode.

txaus ntshai lasers

Los ntawm 3a chav kawm ntawv muaj xws li pab kiag li lawm uas tsis raug mob los ntawm nyuag raug mus rau lub kev tiv thaiv lub qhov muag. Yuav ua tau txaus ntshai thaum uas siv cov tsom optics, piv txwv li telescopes, rub kom pom loj thiab binoculars. Piv txwv: ib tug Helium-neon laser hwj chim ntawm 1-5 mW, ib co laser pointers thiab lub tsev theem.

3b chav kawm ntawv laser beam yuav ua rau raug mob los yog los ntawm tej yam uas muaj nws daim iav duab. Piv txwv li: ib tug Helium-neon laser hwj chim ntawm 5-500 mW, ntau cov kev tshawb fawb thiab kho lasers.

Class 4 muaj xws li ib tug ntaus nrog lub hwj huam ntau ntau uas ntau tshaj 500 mW. Lawv yog cov txaus ntshai rau lub ob lub qhov muag, daim tawv nqaij, raws li zoo raws li ib tug tua hluav taws teeb meem. Raug cov beam ntawm nws specular los yog diffuse reflections yuav ua rau qhov muag thiab tej tawv nqaij raug mob. tag nrho cov kev ruaj ntseg ntsuas yuav tsum tau npaum li cas. QAUV: Nd: yag-lasers, qhia, kev phais, hlau txiav.

Laser tawg: Kev pab tiv thaiv

Txhua kuaj yuav tsum tau muab txaus tiv thaiv rau cov neeg ua hauj lwm nrog lasers. Improvement qhov rais los ntawm kev uas tawg yuav kis tau pab kiag li lawm 2, 3 los yog 4 chav kawm nrog crippling nyob rau hauv uncontrolled chaw yuav tsum tau them los yog lwm yam kev tiv thaiv thaum lub sij hawm kev lag luam ntawm xws li ib tug ntaus ntawv. Rau siab tshaj plaws kev tiv thaiv, nws yog pom zoo kom hais tias qhov muag.

• Lub beam yuav tsum tau muab ntim rau hauv ib lub uas tsis yog-kev nplaim taws resistant tiv thaiv npog rau txo txoj kev pheej hmoo ntawm cov lo raug los yog hluav taws kub. Dlhos lub beam siv fluorescent cov ntxaij vab tshaus los sis theem nrab viewfinders; Tsis txhob direct qhov muag raug.
• Rau lub beam kawm tuab si lug txheej txheem siv tus nqi qis tshaj lub hwj chim. Yog hais tias ua tau rau lub sij hawm luag kawm tuab si lug txheej txheem siv ib tug tsawg-end kiag li lawm. Tsis txhob ruaj xub ntiag ntawm paab khoom nyob rau hauv lub laser cheeb tsam.
• Txwv tsis pub cov zaj uas lub beam nyob rau hauv ib tug txaus ntshai cheeb tsam tom qab cov sij hawm, siv ib tug shutter, thiab lwm yam obstacles. Tsis txhob siv lub phab ntsa ntawm chav tsev dlhos lub beam laser chav kawm ntawv 3b thiab 4.
• Siv tsis paab seev. Ib txhia cov khoom tsis muaj kev cuam tshuam pom lub teeb, nws yuav ib daim iav nyob rau hauv lub invisible ib feem ntawm lub spectrum.
• Tsis txhob hnav paab hniav nyiaj hniav kub. Nws yog xim hlau decorations kuj ua rau kom cov kev pheej hmoo ntawm hluav taws xob poob siab.

kev tiv thaiv tsom iav

Thaum ua hauj lwm nrog lasers 4 chav kawm nrog cov kev txaus ntshai tsam qhib, los yog nyob rau kev pheej hmoo ntawm thiaj yuav tsum tau siv kev tiv thaiv tsom iav. Ntaus lawv nyob rau hauv lub hom ntawm hluav taws xob. Cov ntsiab lus yuav tsum tau xaiv los tiv thaiv reflections, tshwj xeeb tshaj yog diffuse, raws li zoo raws li muab kev tiv thaiv mus rau ib theem uas lub ntuj tiv thaiv reflex yuav tiv thaiv tau qhov muag raug mob. Tej kho qhov muag pab kiag li lawm kom ib co semblance ntawm lub beam, los mus tiv thaiv cov tawv nqaij kub hnyiab, txhob ntawm lwm cov xwm txheej.

Yam tseem ceeb los xav txog thaum xaiv eyewear:

• los yog lub wavelength cheeb tsam ntawm lub tawg spectrum;
• absorbance hauv ib lub wavelength;
• nyiaj pab ntau tshaj illuminance (W / cm ²⁾ los yog lub beam hwj chim (W);
• ntaus laser system;
• Fais fab hom - pulsed laser tawg los yog nruam hom;
• thiaj muaj peev xwm - specular thiab diffuse;
• lub tshav pob ntawm view;
• nyob rau ntawm kho lo ntsiab muag los loj txaus rau cov hnav tsom iav qhov muag kho;
• kev nplij siab;
• cua qhib los mus tiv thaiv misting;
• effect rau xim lub zeem muag;
• kev cuam tshuam kuj;
• lub peev xwm los ua qhov tsim nyog paub tab.

Txij li thaum lub tsom iav yog cov nquag mus puas tsuaj thiab hnav, kuaj kev nyab xeeb yuav tsum muaj xws li periodic inspections ntawm cov kev tiv thaiv cov ntsiab.