Laser qhov chaw technology rauoptical fiber ntausensing Part Ib
Optical fiber sensing thev naus laus zis yog ib hom kev paub txog technology tsim nrog rau kev siv tshuab fiber ntau thiab kev sib txuas lus fiber ntau, thiab nws tau dhau los ua ib feem ntawm cov haujlwm siv tshuab photoelectric.Optical fiber sensing system yog tsim los ntawm laser, kis tau tus mob fiber, sensing element los yog modulation cheeb tsam, lub teeb nrhiav pom thiab lwm yam.Cov tsis tau piav qhia txog cov yam ntxwv ntawm lub teeb yoj muaj xws li kev siv zog, wavelength, theem, polarization xeev, thiab lwm yam. Cov kev txwv no tuaj yeem hloov pauv los ntawm kev cuam tshuam sab nraud hauv kev xa xov fiber ntau.Piv txwv li, thaum kub, lim, siab, tam sim no, hloov chaw, vibration, rotation, dabtsi yog khoov thiab tshuaj muaj pes tsawg leeg cuam tshuam rau txoj kev kho qhov muag, cov kev tsis sib xws.Optical fiber sensing yog ua raws li kev sib raug zoo ntawm cov kev txwv no thiab lwm yam khoom siv los kuaj xyuas qhov sib thooj ntawm lub cev.
Muaj ntau homlaser qhov chawsiv nyob rau hauv optical fiber sensing systems, uas yuav muab faib ua ob pawg: coherentlaser qhov chawthiab incoherent light sources, incoherentqhov chaw teebFeem ntau suav nrog lub teeb incandescent thiab lub teeb-emitting diodes, thiab coherent lub teeb muaj xws li cov khoom lasers, kua lasers, roj lasers,semiconductor laserthiabfiber ntau laser.Cov hauv qab no feem ntau yog rau covlaser qhov chawdav siv nyob rau hauv lub teb ntawm fiber sensing nyob rau hauv xyoo tas los no: nqaim kab dav ib zaus laser, ib leeg-wavelength cheb zaus laser thiab dawb laser.
1.1 Kev xav tau rau txoj kab nqaimlaser qhov chaw
Optical fiber sensing system tsis tuaj yeem raug cais tawm ntawm lub laser qhov chaw, raws li ntsuas lub teeb liab nqa lub teeb yoj, laser lub teeb qhov chaw nws tus kheej kev ua tau zoo, xws li lub zog ruaj khov, laser linewidth, theem suab nrov thiab lwm yam tsis muaj nyob rau ntawm qhov muag pom qhov muag pom kev deb, nrhiav kom pom. qhov tseeb, rhiab heev thiab lub suab nrov ua lub luag haujlwm txiav txim siab.Nyob rau hauv xyoo tas los no, nrog rau kev txhim kho ntawm qhov ntev-ntev ultra-siab daws teeb meem optical fiber sensing systems, academia thiab kev lag luam tau muab tso rau pem hauv ntej ntau stringent yuav tsum tau rau lub linewidth kev ua tau zoo ntawm laser miniaturization, feem ntau nyob rau hauv: optical frequency domain reflection (OFDR) technology siv coherent. Kev tshawb nrhiav thev naus laus zis los txheeb xyuas cov backrayleigh tawg cov teeb liab ntawm optical fibers nyob rau hauv qhov zaus, nrog rau qhov dav dav (ntau txhiab meters).Qhov zoo ntawm kev daws teeb meem siab (millimeter-theem daws teeb meem) thiab siab rhiab heev (txog -100 dBm) tau dhau los ua ib qho ntawm cov thev naus laus zis nrog rau kev siv dav dav hauv kev faib khoom siv fiber ntau ntsuas thiab ntsuas tshuab.Lub hauv paus ntawm OFDR thev naus laus zis yog siv lub teeb ci tunable kom ua tiav qhov kev kho qhov muag zaus, yog li kev ua haujlwm ntawm lub laser txiav txim siab qhov tseem ceeb xws li OFDR nrhiav tau ntau yam, rhiab heev thiab kev daws teeb meem.Thaum qhov kev xav ntawm qhov taw tes nyob ze ze rau qhov ntev ntawm qhov sib txuam, qhov kev siv ntawm lub teeb liab tuav yuav raug exponentially attenuated los ntawm coefficient τ/τc.Rau Gaussian lub teeb pom kev zoo nrog cov duab spectral, txhawm rau kom ntseeg tau tias qhov sib tw zaus muaj ntau dua 90% pom, kev sib raug zoo ntawm kab dav ntawm lub teeb ci thiab qhov siab tshaj qhov ntev uas lub kaw lus tuaj yeem ua tiav yog Lmax ~ 0.04vg /f, uas txhais tau hais tias rau fiber ntau nrog qhov ntev ntawm 80 km, txoj kab dav ntawm lub teeb ci yog tsawg dua 100 Hz.Tsis tas li ntawd, txoj kev loj hlob ntawm lwm yam kev siv kuj tau muab cov kev xav tau siab dua rau cov kab dav dav ntawm lub teeb ci.Piv txwv li, nyob rau hauv lub optical fiber hydrophone system, lub linewidth ntawm lub teeb qhov chaw txiav txim lub suab nrov system thiab kuj txiav txim qhov tsawg kawg nkaus ntsuas teeb liab ntawm lub system.Hauv Brillouin optical time domain reflector (BOTDR), qhov ntsuas kev daws teeb meem ntawm qhov kub thiab txias yog txiav txim siab los ntawm linewidth ntawm lub teeb ci.Nyob rau hauv lub resonator fiber optic gyro, lub coherence ntev ntawm lub teeb yoj tuaj yeem nce los ntawm kev txo cov kab dav ntawm lub teeb ci, yog li txhim kho qhov zoo thiab qhov tob resonance ntawm lub resonator, txo cov kab dav ntawm lub resonator, thiab xyuas kom meej qhov ntsuas. qhov tseeb ntawm fiber ntau optic gyro.
1.2 Cov kev xav tau rau cheb laser qhov chaw
Ib qho wavelength cheb laser muaj qhov hloov pauv tau hloov pauv qhov kev ua tau zoo, tuaj yeem hloov ntau qhov tso zis ruaj khov wavelength lasers, txo tus nqi ntawm kev tsim kho, yog ib feem tseem ceeb ntawm cov khoom siv fiber ntau.Piv txwv li, nyob rau hauv kab noj hniav fiber ntau sensing, ntau hom gases muaj ntau cov pa nqus peaks.Txhawm rau kom ntseeg tau lub teeb pom kev zoo thaum ntsuas roj txaus thiab ua tiav kev ntsuas siab dua, nws yog qhov yuav tsum tau ua kom lub wavelength ntawm lub teeb kis tau tus mob nrog lub siab nqus ntawm cov roj molecule.Hom roj uas tuaj yeem kuaj pom yog qhov tseem ceeb txiav txim siab los ntawm lub wavelength ntawm qhov pom lub teeb pom kev.Yog li ntawd, nqaim linewidth lasers nrog ruaj khov broadband tuning kev ua tau zoo muaj kev ntsuas siab dua nyob rau hauv xws li sensing systems.Piv txwv li, nyob rau hauv ib co faib kho qhov muag fiber sensing systems raws li optical zaus domain reflection, lub laser yuav tsum tau sai sai swept ib ntus kom tiav high-precision coherent nrhiav kom tau thiab demodulation ntawm kho qhov muag teeb liab, yog li ntawd tus nqi modulation ntawm lub laser qhov chaw muaj kuj yuav tsum tau siab. , thiab cheb ceev ntawm lub adjustable laser feem ntau yuav tsum tau mus txog 10 pm / μs.Tsis tas li ntawd, lub wavelength tunable nqaim linewidth laser kuj tuaj yeem siv dav hauv liDAR, laser tej thaj chaw deb sensing thiab high-resolution spectral tsom xam thiab lwm yam sensing teb.Txhawm rau kom ua tau raws li qhov yuav tsum tau ua ntawm kev ua haujlwm siab ntawm kev sib tw bandwidth, kev kho qhov tseeb thiab qhov nrawm ntawm ib lub wavelength lasers nyob rau hauv qhov chaw ntawm fiber ntau sensing, tag nrho lub hom phiaj ntawm kev kawm tunable nqaim-dav fiber ntau lasers nyob rau hauv xyoo tas los no yog kom ua tiav high- precision tuning nyob rau hauv ib tug loj wavelength ntau yam nyob rau hauv lub hauv paus ntawm nrhiav ultra-luv laser linewidth, ultra-low theem suab nrov, thiab ultra-stable tso zis zaus thiab lub zog.
1.3 Xav tau dawb laser qhov chaw
Nyob rau hauv lub tshav pob ntawm optical sensing, high-zoo dawb lub teeb laser yog qhov tseem ceeb heev los txhim kho cov kev ua tau zoo ntawm lub system.Qhov dav dua qhov spectrum kev pab cuam ntawm lub teeb dawb laser, qhov ntau nws daim ntawv thov nyob rau hauv optical fiber sensing system.Piv txwv li, thaum siv fiber ntau Bragg grating (FBG) los tsim ib lub network sensor, spectral tsom xam los yog tunable lim txuam txoj kev yuav siv tau rau demodulation.Tus qub siv lub spectrometer ncaj qha mus kuaj txhua FBG resonant wavelength hauv lub network.Lub tom kawg siv cov lim dej siv los taug qab thiab ntsuas FBG hauv qhov kev paub, ob qho tib si yuav tsum muaj lub teeb pom kev dav dav raws li qhov ntsuas lub teeb rau FBG.Vim tias txhua lub FBG nkag network yuav muaj qee qhov kev nkag tsis tau, thiab muaj qhov bandwidth ntau dua 0.1 nm, ib txhij demodulation ntawm ntau FBG yuav tsum muaj lub teeb pom kev dav dav nrog lub zog siab thiab siab bandwidth.Piv txwv li, thaum siv lub sij hawm ntev fiber ntau grating (LPFG) rau sensing, txij li thaum lub bandwidth ntawm ib tug poob ncov yog nyob rau hauv qhov kev txiav txim ntawm 10 nm, ib tug dav spectrum lub teeb qhov chaw nrog txaus bandwidth thiab kuj tiaj spectrum yog yuav tsum tau kom meej characterize nws resonant. ncov yam ntxwv.Tshwj xeeb, acoustic fiber grating (AIFG) tsim los ntawm kev siv cov nyhuv acousto-optical tuaj yeem ua tiav qhov kev sib tw ntawm resonant wavelength mus txog 1000 nm los ntawm kev siv hluav taws xob.Yog li ntawd, dynamic grating xeem nrog xws li ib tug ultra-wide tuning ntau poses ib tug zoo kev sib tw rau lub bandwidth ntau ntawm ib tug dav-spectrum teeb qhov chaw.Ib yam li ntawd, nyob rau hauv xyoo tas los no, tilted Bragg fiber grating kuj tau siv dav hauv kev paub txog fiber ntau.Vim nws cov yam ntxwv ntawm ntau lub ncov poob spectrum, lub wavelength tis ntau tuaj yeem ncav cuag 40 nm.Nws qhov kev hnov mob feem ntau yog los sib piv cov txheeb ze txav ntawm ntau qhov sib kis, yog li nws yog qhov tsim nyog los ntsuas nws qhov kis tau tus mob tag nrho.Lub bandwidth thiab lub zog ntawm qhov dav spectrum teeb pom kev zoo yuav tsum tau siab dua.
2. Kev tshawb fawb hauv tsev thiab txawv teb chaws
2.1 Nqaim linewidth laser teeb qhov chaw
2.1.1 Nqaim linewidth semiconductor faib tawm tswv yim laser
Xyoo 2006, Cliche et al.txo qhov MHz nplai ntawm semiconductorDFB laser(distributed tawm tswv yim laser) rau kHz nplai siv hluav taws xob tawm tswv yim txoj kev;Xyoo 2011, Kessler et al.siv tsis tshua muaj kub thiab siab ruaj khov ib leeg siv lead ua kab noj hniav ua ke nrog kev tawm tswv yim tswj kom tau txais ultra-qis linewidth laser tso zis ntawm 40 MHz;Nyob rau hauv 2013, Peng li al tau txais ib tug semiconductor laser tso zis nrog ib tug linewidth ntawm 15 kHz los ntawm kev siv tus txheej txheem ntawm sab nraud Fabry-Perot (FP) tawm tswv yim hloov.Txoj kev tawm tswv yim hluav taws xob feem ntau yog siv lub Pond-Drever-Hall zaus stabilization tawm tswv yim los ua kom lub laser linewidth ntawm lub teeb qhov chaw raug txo.Xyoo 2010, Bernhardi et al.ua 1 cm ntawm erbium-doped alumina FBG ntawm silicon oxide substrate kom tau ib tug laser tso zis nrog ib tug kab dav ntawm txog 1.7 kHz.Nyob rau hauv tib lub xyoo, Liang et al.siv tus kheej txhaj tshuaj tawm tswv yim rov qab Rayleigh tawg ua los ntawm high-Q ncha phab ntsa resonator rau semiconductor laser kab-dav compression, raws li qhia nyob rau hauv daim duab 1, thiab thaum kawg tau ib tug nqaim-dav laser output ntawm 160 Hz.
Fig. 1 (a) Daim duab ntawm semiconductor laser linewidth compression raws li tus kheej-txhaj tshuaj Rayleigh scattering ntawm lwm tus ntxhib ntxhib gallery hom resonator;
(b) Ntau zaus spectrum ntawm cov dawb khiav semiconductor laser nrog linewidth ntawm 8 MHz;
(c) Ntau zaus spectrum ntawm lub laser nrog linewidth compressed rau 160 Hz
2.1.2 Nqaim linewidth fiber ntau laser
Rau linear kab noj hniav fiber ntau lasers, nqaim linewidth laser tso zis ntawm ib hom longitudinal yog tau los ntawm shortening qhov ntev ntawm resonator thiab ua rau longitudinal hom ncua sij hawm.Xyoo 2004, Spiegelberg et al.tau txais ib hom longitudinal nqaim linewidth laser tso zis nrog ib tug linewidth ntawm 2 kHz los ntawm kev siv DBR luv kab noj hniav txoj kev.Xyoo 2007, Shen et al.siv 2 cm hnyav erbium-doped silicon fiber ntau los sau FBG ntawm Bi-Ge co-doped photosensitive fiber, thiab fused nws nrog ib tug nquag fiber ntau los ua ib tug compact linear kab noj hniav, ua rau nws laser output kab dav tsawg tshaj li 1 kHz.Xyoo 2010, Yang et al.siv 2cm siab doped luv luv linear kab noj hniav ua ke nrog ib tug nqaim band FBG lim kom tau ib tug longitudinal hom laser tso zis nrog ib tug kab dav ntawm tsawg tshaj li 2 kHz.Nyob rau hauv 2014, pab neeg siv ib tug luv luv linear kab noj hniav (virtual folded nplhaib resonator) ua ke nrog ib tug FBG-FP lim kom tau ib tug laser tso zis nrog ib tug nqaim kab dav, raws li qhia nyob rau hauv daim duab 3. Nyob rau hauv 2012, Cai li al.siv lub 1.4cm luv kab noj hniav qauv kom tau ib tug polarizing laser tso zis nrog ib tug tso zis hwj chim ntau tshaj 114 mW, lub nruab nrab wavelength ntawm 1540.3 nm, thiab ib tug kab dav ntawm 4.1 kHz.Xyoo 2013, Meng et al.siv Brillouin tawg ntawm erbium-doped fiber ntau nrog lub nplhaib luv luv ntawm cov khoom siv kom ruaj khov kom tau txais ib hom kab ntev, qis-theem suab nrov laser tso zis nrog lub zog tso zis ntawm 10 mW.Hauv xyoo 2015, pab pawg tau siv lub nplhaib kab noj hniav uas muaj 45 cm erbium-doped fiber ntau raws li Brillouin tawg tau nce nruab nrab kom tau txais qhov pib qis thiab nqaim linewidth laser tso zis.
Daim duab 2 (a) Schematic daim duab ntawm SLC fiber ntau laser;
(b) Lineshape ntawm lub teeb liab heterodyne ntsuas nrog 97.6 km fiber ntau ncua
Post lub sij hawm: Nov-20-2023