Excitation ntawm ob harmonics nyob rau hauv ib tug dav spectrum

Excitation ntawm ob harmonics nyob rau hauv ib tug dav spectrum

Txij li thaum qhov kev tshawb pom ntawm qhov kev txiav txim thib ob uas tsis yog kab hluav taws xob kho qhov muag hauv xyoo 1960, tau ua rau muaj kev txaus siab ntawm cov neeg tshawb fawb, kom deb li deb, raws li qhov kev sib raug zoo thib ob, thiab cov teebmeem zaus, tau tsim los ntawm huab cua ultraviolet mus rau qhov deb infrared band.lasers, zoo heev txhawb txoj kev loj hlob ntawm laser,kho qhov muagkev ua cov ntaub ntawv, kev daws teeb meem siab microscopic imaging thiab lwm yam. Raws li nonlinearopticsthiab polarization txoj kev xav, qhov kev txiav txim tsis yog-linear kho qhov muag muaj feem cuam tshuam nrog siv lead ua symmetry, thiab cov nonlinear coefficient tsis yog xoom nkaus xwb hauv cov xov xwm uas tsis yog-central inversion symmetrical media. Raws li qhov tseem ceeb tshaj plaws thib ob-order nonlinear nyhuv, qhov thib ob harmonics zoo heev cuam tshuam lawv tiam thiab siv tau zoo nyob rau hauv quartz fiber ntau vim yog amorphous daim ntawv thiab lub symmetry ntawm nruab nrab inversion. Tam sim no, txoj kev polarization (optical polarization, thermal polarization, hluav taws xob teb polarization) tuaj yeem ua kom puas lub symmetry ntawm cov khoom nruab nrab inversion ntawm optical fiber, thiab zoo txhim kho qhov kev txiav txim thib ob nonlinearity ntawm optical fiber. Txawm li cas los xij, txoj kev no yuav tsum tau siv tshuab ua kom nyuaj thiab xav tau kev npaj, thiab tsuas yog tuaj yeem ua tau raws li qhov sib piv ntawm cov xwm txheej sib txawv ntawm qhov sib txawv wavelengths. Optical fiber resonant nplhaib raws li ncha phab ntsa hom txwv qhov dav spectrum excitation ntawm thib ob harmonics. Los ntawm kev rhuav tshem cov symmetry ntawm cov qauv saum npoo ntawm cov fiber ntau, qhov chaw thib ob harmonics hauv cov qauv tshwj xeeb fiber ntau tau txhim kho rau qee qhov, tab sis tseem nyob ntawm femtosecond twj mem tes nrog lub zog siab kawg. Yog li ntawd, tiam thib ob-order nonlinear optical teebmeem nyob rau hauv tag nrho cov-fiber qauv thiab kev txhim kho kev hloov dua siab tshiab efficiency, tshwj xeeb tshaj yog cov tiam ntawm wide-spectrum thib ob harmonics nyob rau hauv qis-power, nruam optical twj tso kua mis, yog cov yooj yim teeb meem uas yuav tsum tau daws nyob rau hauv lub tshav pob ntawm nonlinear fiber optics thiab pab kiag li lawm, thiab muaj ib tug tseem ceeb scientific qhov tseem ceeb thiab dav daim ntawv thov nqi.

Ib pab neeg tshawb fawb hauv Suav teb tau tshaj tawm cov txheej txheem txheej txheem gallium selenide crystal theem kev koom ua ke nrog micro-nano fiber. Los ntawm kev ua kom zoo dua ntawm qhov kev txiav txim siab thib ob uas tsis yog-linearity thiab kev txiav txim siab ntev ntawm gallium selenide crystals, qhov dav-spectrum thib ob-harmonic excitation thiab ntau zaus hloov dua siab tshiab tau pom, muab cov kev daws teeb meem tshiab rau kev txhim kho cov txheej txheem ntau yam hauv fiber ntau thiab kev npaj ntawm broadband thib ob-harmonic.qhov chaw teeb. Kev ua kom muaj txiaj ntsig zoo ntawm qhov kev sib raug zoo thib ob thiab cov txiaj ntsig ntau zaus hauv cov phiaj xwm feem ntau yog nyob ntawm peb yam tseem ceeb hauv qab no: qhov ntev ntawm lub teeb teeb meem sib cuam tshuam ntawm gallium selenide thiabmicro-nano fiber ntau, qhov siab thib ob-txiav txim siab nonlinearity thiab ntev-ntev kev txiav txim ntawm cov txheej txheem gallium selenide siv lead ua, thiab cov theem sib piv cov xwm txheej ntawm lub hauv paus zaus thiab zaus ob npaug ntawm hom yog txaus siab.

Hauv qhov kev sim, cov micro-nano fiber ntau npaj los ntawm cov nplaim hluav taws xob scanning tapering system muaj lub khob hliav qab hauv qhov kev txiav txim ntawm millimeter, uas muab qhov ntev nonlinear ua haujlwm ntev rau lub teeb pom kev zoo thiab lub teeb pom kev sib haum xeeb thib ob. Qhov thib ob-order nonlinear polarizability ntawm integrated gallium selenide siv lead ua ntau tshaj 170 pm / V, uas yog ntau dua li intrinsic nonlinear polarizability ntawm optical fiber. Tsis tas li ntawd, qhov ntev-ntev txiav txim qauv ntawm lub gallium selenide siv lead ua kom muaj kev cuam tshuam tsis tu ncua ntawm qhov thib ob harmonics, muab kev ua si tag nrho rau qhov kom zoo dua ntawm qhov loj ntawm qhov ntev ntawm micro-nano fiber. Qhov tseem ceeb tshaj plaws, cov theem sib txuam ntawm kev siv lub hauv paus hom (HE11) thiab qhov thib ob harmonic siab txiav txim hom (EH11, HE31) yog paub los ntawm kev tswj lub khob hliav qab thiab ces tswj lub waveguide dispersion thaum lub sij hawm npaj ntawm micro-nano fiber.

Cov xwm txheej saum toj no nteg lub hauv paus rau qhov ua tau zoo thiab dav-band excitation ntawm qhov thib ob harmonics hauv micro-nano fiber ntau. Qhov kev sim qhia tau hais tias qhov tso zis ntawm qhov thib ob harmonics ntawm qib nanowatt tuaj yeem ua tiav raws li 1550 nm picosecond mem tes laser twj tso kua mis, thiab qhov thib ob harmonics kuj tuaj yeem ua rau muaj txiaj ntsig zoo nyob rau hauv lub twj tso kua mis laser txuas ntxiv ntawm tib lub wavelength, thiab lub zog pib yog tsawg li ob peb puas microwatts (Daim duab 1). Ntxiv mus, thaum lub teeb lub twj tso kua mis txuas mus rau peb qhov sib txawv wavelengths ntawm nruam laser (1270/1550/1590 nm), peb thib ob harmonics (2w1, 2w2, 2w3) thiab peb lub cim zaus (w1 + w2, w1 + w3, w2 + w3) yog pom ntawm txhua qhov kev hloov dua siab tshiab. Los ntawm kev hloov lub teeb lub twj tso kua mis nrog lub ultra-radiant light-emitting diode (SLED) lub teeb qhov chaw nrog ib tug bandwidth ntawm 79.3 nm, ib tug dav-spectrum thib ob harmonic nrog ib tug bandwidth ntawm 28.3 nm yog generated (Daim duab 2). Tsis tas li ntawd, yog tias cov tshuaj vapor deposition thev naus laus zis tuaj yeem siv los hloov cov thev naus laus zis hloov pauv qhuav hauv qhov kev tshawb fawb no, thiab cov txheej txheem tsawg dua ntawm gallium selenide muaju tuaj yeem loj hlob ntawm qhov chaw ntawm micro-nano fiber ntau nyob rau qhov ntev, qhov kev sib haum xeeb thib ob yuav tsum tau txhim kho ntxiv.

FIG. 1 Second harmonic tiam system thiab ua rau tag nrho-fiber qauv

Daim duab 2 Multi-wavelength mixing thiab wide-spectrum thib ob harmonics nyob rau hauv tas li kho qhov muag twj tso kua mis