Cov ntsiab cai ntawm optical microscopy nyob ze thaj tsam
Traditional optical microscopes are composed of optical lenses that can magnify objects to thousands of times to observe details. Due to the diffraction effect of light waves, it is impossible to increase the magnification infinitely because it will encounter the obstacle of the diffraction limit of light waves. Traditional optics The resolution of a microscope cannot exceed half the wavelength of light. For example, using green light with a wavelength of λ=400nm as a light source, it can only distinguish two objects that are 200nm apart. In practical applications, λ>400nm, the resolution is lower. This is because general optical observations are performed far away from the object (>>λ).
Raws li kev tshawb nrhiav thiab kev yees duab cov ntsiab lus ntawm cov chaw tsis muaj hluav taws xob, qhov ze-tsawg optical microscopes tuaj yeem tawg los ntawm qhov tsis sib xws ntawm cov khoom siv kho qhov muag zoo tib yam thiab tuaj yeem ua cov duab nanoscale kho qhov muag thiab kev tshawb fawb nanoscale spectral ntawm ultra-high optical daws teeb meem.
Ze-field optical microscopes yog tsim los ntawm kev sojntsuam, cov khoom siv hluav taws xob kis tau tus mob, kev tswj xyuas kev tswj xyuas, kev ua haujlwm teeb liab thiab cov teeb liab tawm tswv yim. Lub hauv paus ntsiab lus ntawm qhov ze ntawm qhov chaw tsim thiab kev tshawb pom: Teeb pom kev zoo irradiates ib yam khoom nrog ntau cov qauv me me ntawm qhov chaw. Nyob rau hauv qhov kev txiav txim ntawm qhov teeb meem teeb pom kev zoo, lub reflected nthwv dej uas tsim los ntawm cov qauv no muaj xws li evanescent nthwv dej txwv rau saum npoo ntawm cov khoom thiab propagated nyob deb. propagating nthwv dej. Evasescent nthwv dej pib los ntawm cov qauv me me hauv cov khoom (cov khoom me dua lub wavelength). Lub propagating yoj los ntawm cov qauv ntxhib ntawm cov khoom (cov khoom loj dua lub wavelength), uas tsis muaj cov ntaub ntawv hais txog cov qauv zoo ntawm cov khoom. Yog tias qhov chaw tawg me me heev yog siv los ua tus nanodetector (xws li kev sojntsuam) thiab muab tso ze txaus rau ntawm qhov khoom, lub evanescent nthwv dej yuav zoo siab thiab ua rau nws tawm lub teeb dua. Lub teeb pom kev zoo siab no tseem muaj cov nthwv dej tsis pom kev tsis pom kev thiab cov nthwv dej uas muaj peev xwm nthuav tawm mus rau qhov chaw nyob deb kom pom. Cov txheej txheem no ua tiav qhov kev tshawb pom ze ntawm thaj chaw. Kev hloov dua siab tshiab ntawm evanescent teb thiab propagating teb yog linear, thiab propagating teb yog qhia tau hais tias cov kev hloov nyob rau hauv evanescent teb. Yog tias lub chaw tawg yog siv los ntsuas qhov saum npoo ntawm ib qho khoom, tuaj yeem tau txais daim duab ob sab. Raws li lub hauv paus ntsiab lus ntawm reciprocity, lub luag hauj lwm ntawm lub illumination lub teeb qhov chaw thiab lub nano-detector yog interchanged, thiab lub nano-light source (evanescent teb) yog siv los illumination tus qauv. Vim qhov cuam tshuam ntawm cov qauv zoo ntawm cov khoom ntawm qhov chaw teeb pom kev zoo, evasescent nthwv dej tau hloov mus rau hauv lub teeb liab uas tuaj yeem kuaj pom ntawm qhov deb. Cov txiaj ntsig ntawm kev kuaj pom propagating nthwv dej yog tib yam nkaus.
Ze-field optical microscopy siv ib qho kev sojntsuam los tshawb xyuas qhov taw tes ntawm qhov taw tes ntawm tus qauv saum npoo thiab sau nws taw tes los ntawm taw tes ua ntej cov duab digital. Daim duab 1 yog lub hauv paus ntsiab lus duab kos duab ntawm ib qho ze-field optical microscope. Nyob rau hauv daim duab, lub xyz ntxhib approximation txoj kev tuaj yeem kho qhov kev ncua deb ntawm qhov kev sojntsuam thiab cov qauv nrog qhov tseeb ntawm kaum ntawm nanometers; thaum lub sij hawm xy scanning thiab z tswj tuaj yeem tswj qhov kev sojntsuam sojntsuam thiab cov lus tawm tswv yim ua raws li z kev taw qhia nrog qhov tseeb ntawm 1nm. Qhov teeb meem laser nyob rau hauv daim duab yog nkag mus rau hauv lub sojntsuam los ntawm ib tug optical fiber, thiab lub polarization lub xeev ntawm teeb meem teeb yuav hloov tau raws li qhov yuav tsum tau. Thaum qhov teeb meem laser irradiates tus qauv, lub detector yuav cais cov kis tau tus mob teeb liab thiab reflection teeb liab modulated los ntawm tus qauv, uas yog amplified los ntawm lub photomultiplier raj, thiab ces ncaj qha hloov los ntawm analog rau digital thiab ces sau los ntawm lub computer los yog nkag mus rau hauv lub photomultiplier tube. spectrometer los ntawm lub spectroscopic system kom tau cov spectrum. cov ntaub ntawv. Kev tswj hwm qhov system, sau cov ntaub ntawv, duab tso saib thiab ua cov ntaub ntawv yog txhua yam ua tiav los ntawm cov khoos phis tawj. Nws tuaj yeem pom los ntawm cov txheej txheem kev kos duab saum toj no uas ze-field optical microscopes tuaj yeem sau peb hom ntaub ntawv tib lub sijhawm, uas yog lub ntsej muag morphology ntawm tus qauv, ze-teeb kho qhov muag teeb liab thiab spectral signals.
