Ua tsaug rau topology, ib ceg ntawm kev ua lej uas tshawb txog cov khoom ntawm cov khoom geometric uas nyob twj ywm tib yam thaum tab tom ua tsis tu ncua deformations, ib pab pawg kws tshawb fawb coj los ntawm Isaac Nape ntawm University of the Witwatersrand hauv South Africa thiab Kayne Forbes ntawm University of East Anglia (UEA) hauv UK nrhiav tau ib txoj hauv kev rau kev pab cuam thiab tswj lub teeb ci {5} thiab sab laug {5} spin.
Nyob rau hauv optics, chirality feem ntau yog txuam nrog lub voj voog polarized (nyob rau hauv uas lub teb hluav taws xob tig los yog clockwise los yog anticlockwise raws li lub teeb mus).
"Peb txoj haujlwm tau mob siab rau los ntawm cov lus nug ntawm seb lub teeb puas tuaj yeem tsim thiab tswj nws tus kheej hauv zos los ntawm kev nthuav tawm - yam tsis xav tau cov khoom siv sib cuam tshuam, metasurface, lossis nruj heev," said Forbes, tus kws qhia ntawv ntawm UEA Lub Tsev Kawm Ntawv ntawm Chemistry, Pharmacy, thiab Pharmacology, qhov chaw uas nws ua tus coj lub teeb -Cov teeb meem thiab Nanan.
Topological nqi tweak
Topology nkag mus rau hauv txoj kev ntawm theem thiab polarization ntawm lub teeb beam cua nyob ib ncig ntawm qhov chaw. "Structured light cia peb coj cov tswv yim no ua ke kom peb tuaj yeem tsim cov kab teeb uas nws theem thiab polarization sib txawv hauv txoj hauv kev meej thoob plaws kab," piav qhia Forbes. "Peb tau xav txog qhov muaj peev xwm ntawm topology ntawm lub nqaj ua haujlwm raws li lub pob qhov rooj tswj tau yooj yim. Los ntawm kev hloov pauv Pancharatnam topological nqi (ib qho kev ntsuas), peb tuaj yeem ua rau lub zos spin thiab chirality ntawm lub teeb reorganize lawv tus kheej thaum propagation."
Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias tsis muaj cov khoom tshwj xeeb xav tau rau cov nyhuv nws tus kheej. Lub kiv thiab chirality tshwm sim thaum lub sijhawm pub dawb - qhov chaw nthuav tawm ntawm lub teeb teeb pom kev zoo -vector vortex beam, hauv qhov no.
Dab tsi yog vector vortex beam? "Vector txhais tau tias lub polarization sib txawv ntawm cov nqaj, es tsis yog qhov sib xws," Forbes hais. "Vortex txhais tau hais tias lub nqaj nqa lub orbital angular momentum, uas yog txuam nrog ib theem twisted pem hauv ntej. Thiab topology nkag los ntawm txoj kev cov nqaj twists nyob ib ncig ntawm nws tus kheej axis. Nyob rau hauv peb txoj hauj lwm, qhov twist no yog tswj los ntawm lub Pancharatnam topological nqi, uas teev yuav ua li cas lub beam theem thiab polarization txawv raws li peb tsiv mus nyob ib ncig ntawm lub beam."
Ntawm lub dav hlau pib, lub nqaj yog tig- sib npaug. Nws sab laug- thiab sab xis- cov khoom vaj huam sib luag yog tam sim no sib npaug, yog li tsis muaj lub voj voog polarization hauv zos. "Tab sis ob lub ntsiab lus no muaj cov qauv sib txawv ntawm lub orbital," Forbes taw qhia. "Raws li lub beam propagates, lawv tau txais cov Gouy theem sib txawv thiab txawv radial profiles. Qhov no ua rau txoj cai - thiab sab laug-xov cov khoom sib cais cais radially, uas ua rau lub zos spin thiab optical chirality."
Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias tsis muaj cov khoom tshwj xeeb xav tau rau cov nyhuv nws tus kheej. Lub kiv thiab chirality tshwm sim thaum lub sijhawm pub dawb - qhov chaw nthuav tawm ntawm lub teeb teeb pom kev zoo -vector vortex beam, hauv qhov no.
Dab tsi yog vector vortex beam? "Vector txhais tau tias lub polarization sib txawv ntawm cov nqaj, es tsis yog qhov sib xws," Forbes hais. "Vortex txhais tau hais tias lub nqaj nqa lub orbital angular momentum, uas yog txuam nrog ib theem twisted pem hauv ntej. Thiab topology nkag los ntawm txoj kev cov nqaj twists nyob ib ncig ntawm nws tus kheej axis. Nyob rau hauv peb txoj hauj lwm, qhov twist no yog tswj los ntawm lub Pancharatnam topological nqi, uas teev yuav ua li cas lub beam theem thiab polarization txawv raws li peb tsiv mus nyob ib ncig ntawm lub beam."
Ntawm lub dav hlau pib, lub nqaj yog tig- sib npaug. Nws sab laug- thiab sab xis- cov khoom vaj huam sib luag yog tam sim no sib npaug, yog li tsis muaj lub voj voog polarization hauv zos. "Tab sis ob lub ntsiab lus no muaj cov qauv sib txawv ntawm lub orbital," Forbes taw qhia. "Raws li lub beam propagates, lawv tau txais cov Gouy theem sib txawv thiab txawv radial profiles. Qhov no ua rau txoj cai - thiab sab laug-xov cov khoom sib cais cais radially, uas ua rau lub zos spin thiab optical chirality."
Structured light photonics, optical manipulation, chiral sensing
Peb ntawm daim ntawv thov pom tseeb tshaj plaws tom ntej yog qhov zoo li teeb pom kev zoo photonics, kho qhov muag kho qhov muag, thiab chiral sensing. Lwm qhov muaj peev xwm siv tau yog siab -dimensional photonic cov ntaub ntawv ua, vim hais tias cov nqaj txuas spin thiab orbital angular momentum nyob rau hauv ib txoj kev tswj tau.
"Hauv txoj cai, peb qhov kev tshawb pom muaj feem cuam tshuam rau ob qho tib si classical thiab quantum teeb pom kev zoo, qhov twg cov ntaub ntawv tuaj yeem nkag mus rau hauv polarization (spinning light) thiab spatial modes (twisted light)," Nape hais. "Lub photon spin thiab twist tuaj yeem siv los ua cov tsiaj ntawv hauv cov kab teeb ci laser thiab ntawm ib theem photon. Txhua lub xeev sib txawv sawv cev rau cov ntaub ntawv sib txawv."
Pab pawg ua haujlwm tam sim no yog classical optical physics, tab sis tib qib kev ywj pheej, kiv, orbital angular momentum, thiab spatial hom qauv kuj siv rau quantum photonics. "Peb lub sijhawm ntev dua - qhov kev txaus siab yog seb hom topology no - tswj kev tig- lub voj voog tuaj yeem muaj txiaj ntsig zoo rau kev npaj, hloov pauv, lossis encoding siab -dimensional photonic xeev," hais Nape.
Tom ntej no, cov kws tshawb fawb tau npaj los tshawb xyuas seb qhov txheej txheem no muaj txiaj ntsig zoo li cas. "Peb tau pom tias Pancharatnam topological nqi tuaj yeem tswj cov kiv thiab chirality dawb -qhov chaw nthuav tawm, thiab tam sim no cov lus nug yog tias qhov kev tswj no tuaj yeem thawb mus deb npaum li cas," Nape hais. "Peb kuj xav paub yuav ua li cas nws tuaj yeem siv rau cov ntaub ntawv encoding, kho qhov muag kho qhov muag, thiab chiral light- teeb meem kev sib cuam tshuam. Peb lub hom phiaj dav dua yog txav los ntawm kev nthuav tawm lub teeb pom kev zoo rau kev tsim nws raws li cov qauv tsim qauv. "
