Fasaha tushen Laser donfiber na ganijin Kashi na daya
Fasahar gano fiber na gani wani nau'i ne na fasaha na ganowa da aka haɓaka tare da fasahar fiber na gani da fasahar sadarwar fiber na gani, kuma ya zama ɗaya daga cikin rassa mafi ƙarfi na fasahar hoto. Tsarin gano fiber na gani yana kunshe da Laser, fiber watsawa, yanki mai ji ko daidaitawa, gano haske da sauran sassa. Siffofin da ke bayyana halayen igiyar haske sun haɗa da ƙarfi, tsayin raƙuman ruwa, lokaci, yanayin polarization, da sauransu. Waɗannan sigogi na iya canza su ta hanyar tasirin waje a cikin watsa fiber na gani. Misali, lokacin da zafin jiki, damuwa, matsa lamba, halin yanzu, ƙaura, girgizawa, juyawa, lanƙwasa da adadin sinadarai sun shafi hanyar gani, waɗannan sigogi suna canzawa daidai. Hannun fiber na gani yana dogara ne akan alakar da ke tsakanin waɗannan sigogi da abubuwan waje don gano daidaitattun adadin jiki.
Akwai nau'ikan iri da yawatushen laserana amfani da su a cikin tsarin gano fiber na gani, wanda za'a iya raba shi zuwa rukuni biyu: daidaitaccetushen laserda maɓuɓɓugan haske marasa daidaituwa, marasa daidaituwahanyoyin haskeyafi hada da incandescent haske da haske-emitting diodes, da kuma madaidaicin hanyoyin haske sun haɗa da m lasers, ruwa Laser, gas Laser,semiconductor Laserkumafiber Laser. Abubuwan da ke biyowa galibi donLaser haske tushenAn yi amfani da shi sosai a fagen ji na fiber a cikin 'yan shekarun nan: kunkuntar layi mai faɗin Laser-mita-ɗaya, Laser mai tsaftar tsayin tsayin tsayin daka da farin Laser.
1.1 Abubuwan buƙatu don kunkuntar layin layiLaser haske kafofin
Na gani fiber ji tsarin ba za a iya raba daga Laser tushen, kamar yadda auna siginar m igiyar haske kalaman, Laser haske Madogararsa kanta yi, kamar ikon kwanciyar hankali, Laser linewidth, lokaci amo da sauran sigogi a kan Tantancewar fiber ji tsarin gano nesa, ganewa daidaito, hankali da kuma amo halaye taka muhimmiyar rawa. A cikin 'yan shekarun nan, tare da ci gaban dogon nisa matsananci-high ƙuduri Tantancewar fiber ji tsarin, ilimi da kuma masana'antu sun gabatar da ƙarin stringent bukatun ga linewidth yi na Laser miniaturization, yafi a: Tantancewar yankin tunani (OFDR) fasaha yana amfani da m ganewa fasaha don nazarin backrayleigh warwatsa sigina na Tantancewar zaruruwa a cikin mita (tare da wani m yanki). Abubuwan da ake amfani da su na babban ƙuduri (ƙudurin matakin-millimita) da ƙwarewa mai girma (har zuwa -100 dBm) sun zama ɗaya daga cikin fasahar da ke da fa'idar aikace-aikacen aikace-aikace a cikin rarraba ma'aunin fiber na gani da fasahar ji. Jigon fasahar OFDR shine amfani da tushen haske mai kunnawa don cimma daidaitawar mitar gani, don haka aikin tushen Laser yana ƙayyade mahimman abubuwan kamar kewayon gano OFDR, hankali da ƙuduri. Lokacin da nisa na tunani ya kusa kusa da tsayin haɗin kai, ƙarfin siginar bugun za a rage shi da ƙarfi ta hanyar ƙididdigewa τ/τc. Don tushen haske na Gaussian tare da nau'i mai ban sha'awa, don tabbatar da cewa mitar bugun yana da fiye da 90% ganuwa, dangantakar dake tsakanin layin layi na hasken haske da matsakaicin tsayin tsayin da tsarin zai iya cimma shine Lmax ~ 0.04vg / f, wanda ke nufin cewa don fiber tare da tsawon 80 km, layin nisa na tushen hasken ya kasance ƙasa da 100 Hz. Bugu da kari, ci gaban wasu aikace-aikace kuma ya gabatar da buƙatu mafi girma don layin layin haske. Misali, a cikin tsarin hydrophone na fiber na gani, layin layin tushen hasken yana ƙayyade ƙarar tsarin kuma yana ƙayyade mafi ƙarancin siginar tsarin. A Brillouin Optical Time domain reflector (BOTDR), ƙudirin auna zafin jiki da damuwa an ƙaddara shi ta hanyar layin haske. A cikin resonator fiber optic gyro, za a iya ƙara daidaituwar tsayin igiyoyin hasken ta hanyar rage nisa layin tushen hasken, ta haka inganta inganci da zurfin resonance na resonator, rage layin nisa na resonator, da tabbatar da daidaiton ma'aunin fiber optic gyro.
1.2 Abubuwan buƙatun don share tushen laser
Single wavelength share Laser yana da m zango kunna yi, na iya maye gurbin mahara fitarwa kafaffen igiyar ruwa Laser, rage farashin tsarin yi, shi ne wani makawa ɓangare na Tantancewar fiber ji tsarin. Misali, a cikin gano fiber gas, nau'ikan iskar gas daban-daban suna da kololuwar sharar iskar gas daban-daban. Don tabbatar da ingancin ɗaukar haske lokacin da iskar gas ɗin auna ya isa kuma a sami ma'aunin ma'auni mafi girma, ya zama dole a daidaita tsayin daka na tushen hasken watsawa tare da kololuwar ƙwayar iskar gas. Nau'in iskar gas ɗin da za'a iya ganowa ana ƙididdige shi ne ta hanyar tsayin daka na tushen haske. Don haka, kunkuntar leza mai faɗin layi tare da tsayayyen aikin daidaita faɗakarwa suna da sassaucin ma'auni mafi girma a cikin irin waɗannan tsarin ji. Misali, a cikin wasu tsarin firikwensin fiber na gani da aka rarraba dangane da tunanin yanki na mitar gani, Laser yana buƙatar a share shi cikin sauri lokaci-lokaci don cimma daidaitaccen ganewar daidaitaccen daidaituwa da lalata siginar gani, don haka ƙimar ƙirar laser tana da manyan buƙatu, kuma ana buƙatar share saurin laser daidaitacce yawanci don isa 10 pm/μs. Bugu da kari, za a iya amfani da Laser kunkuntar kunkuntar layin nisa na tsawon tsayi a cikin liDAR, Laser nesa mai nisa da bincike mai tsayi mai tsayi da sauran filayen ji. Domin saduwa da bukatu na high yi sigogi na kunna bandwidth, kunna daidaito da kuma kunna gudu guda-wavelength Laser a fagen fiber ji, da overall burin nazarin tunable kunkuntar-nisa fiber Laser a cikin 'yan shekarun nan shi ne cimma high-daidaici kunna a cikin wani ya fi girma igiyar ruwa kewayon a kan bin matsananci-kunkuntar Laser, ultra-narrow ultra-low-threads linewid. iko.
1.3 Buƙatar farin hasken Laser
A fagen hangen nesa, babban ingancin haske mai haske na laser yana da mahimmanci don haɓaka aikin tsarin. Faɗin ɗaukar hoto na farin haske Laser, da ƙarin faɗaɗa aikace-aikacen sa a cikin tsarin gano fiber na gani. Misali, lokacin amfani da fiber Bragg grating (FBG) don gina cibiyar sadarwa na firikwensin, ana iya amfani da bincike na gani ko hanyar daidaita tacewa don lalatawa. Tsohuwar ta yi amfani da na'urar gani don gwada kowane tsayin raƙuman FBG a cikin hanyar sadarwa. Ƙarshen yana amfani da matatar tunani don waƙa da daidaita FBG a cikin ji, dukansu biyu suna buƙatar tushen hasken faɗaɗa a matsayin tushen hasken gwaji don FBG. Domin kowace hanyar sadarwa ta FBG za ta sami asarar shigarwa, kuma tana da bandwidth fiye da 0.1 nm, ƙaddamarwar lokaci ɗaya na FBG da yawa yana buƙatar tushen hasken faɗaɗa tare da babban iko da babban bandwidth. Misali, lokacin amfani da dogon lokaci fiber grating (LPFG) don ji, tun da bandwidth na kololuwar asara guda yana cikin tsari na nm 10, babban tushen hasken bakan tare da isassun bandwidth da ingantacciyar bakan bakan da ake buƙata don daidaita daidaitattun halayensa. Musamman, Acoustic fiber grating (AIFG) da aka gina ta hanyar amfani da tasirin acousto-optical na iya samun damar daidaita kewayon resonant tsayin tsayi har zuwa 1000 nm ta hanyar kunna wutar lantarki. Don haka, gwajin grating mai ƙarfi tare da irin wannan kewayon daidaitawa mai faɗi yana haifar da babban ƙalubale ga kewayon bandwidth na tushen haske mai faɗi. Hakazalika, a cikin 'yan shekarun nan, an yi amfani da ƙwayar fiber na Bragg mai karkatar da shi sosai a fagen sanin fiber. Saboda halayen bakan hasara mai yawa-kololuwa, kewayon rarraba tsayin raƙuman ruwa yawanci na iya kaiwa 40 nm. Hanyar fahimtarsa yawanci shine kwatanta motsin dangi tsakanin kololuwar watsawa da yawa, don haka ya zama dole a auna bakan watsawarsa gaba daya. Ana buƙatar bandwidth da ikon tushen hasken bakan mai faɗi ya zama mafi girma.
2. Matsayin bincike a gida da waje
2.1 Madogarar hasken Laser kunkuntar layin layi
2.1.1 kunkuntar layin layi semiconductor rarraba ra'ayi Laser
A cikin 2006, Cliche et al. rage ma'aunin MHz na semiconductorFarashin DFB(Rarraba ra'ayi Laser) zuwa sikelin kHz ta amfani da hanyar amsawar lantarki; A cikin 2011, Kessler et al. yi amfani da ƙananan zafin jiki da babban kwanciyar hankali kogon kristal guda ɗaya haɗe tare da sarrafa amsawa mai aiki don samun fitarwar Laser mai kunkuntar layin layi na 40 MHz; A cikin 2013, Peng et al sun sami fitowar laser semiconductor tare da layin layi na 15 kHz ta amfani da hanyar daidaitawar martani na Fabry-Perot (FP). Hanyar mayar da martani ta wutar lantarki ta fi amfani da tafsirin tafki-Drever-Hall don tabbatar da ragi na layin haske na Laser. A cikin 2010, Bernhardi et al. ya samar da 1 cm na erbium-doped alumina FBG akan siliki oxide substrate don samun fitarwar laser tare da faɗin layi na kusan 1.7 kHz. A cikin wannan shekarar, Liang et al. yayi amfani da ra'ayin allurar kai-da-kai na watsawar Rayleigh na baya wanda aka kafa ta babban-Q echo bango resonator don matsawa layin Laser na semiconductor, kamar yadda aka nuna a cikin Hoto 1, kuma a ƙarshe ya sami ƙunƙuntaccen fitarwa na Laser mai faɗin 160 Hz.
Hoto 1 (a) Zane na semiconductor Laser linewidth matsawa dangane da kai allurar Rayleigh watsawa na waje raɗaɗi gallery yanayin resonator;
(b) Bakan mita na Laser semiconductor mai gudana kyauta tare da layin layi na 8 MHz;
(c) Mitar bakan Laser tare da layin layi wanda aka matsa zuwa 160 Hz
2.1.2 kunkuntar layin fiber Laser
Don Laser cavity fiber lasers, kunkuntar fitowar Laser mai faɗin layi na yanayin madaidaiciya ɗaya ana samun shi ta hanyar rage tsawon resonator da haɓaka tazarar yanayin a tsaye. A cikin 2004, Spiegelberg et al. ya sami yanayin madaidaiciya guda ɗaya kunkuntar fitarwa na laser layi tare da layin layi na 2 kHz ta amfani da gajeriyar hanyar rami na DBR. A cikin 2007, Shen et al. ya yi amfani da fiber silicon fiber mai girman erbium-doped mai tsayin cm 2 don rubuta FBG akan fiber mai ɗaukar hoto mai haɗin gwiwa na Bi-Ge, kuma ya haɗa shi da fiber mai aiki don samar da ƙaramin rami na madaidaiciya, yana sanya layin fitarwar laser ƙasa da 1 kHz. A cikin 2010, Yang et al. ya yi amfani da ɗan gajeren rami mai tsayi na 2cm mai ƙarfi wanda aka haɗe tare da matattara ta FBG mai kunkuntar don samun fitowar yanayin laser guda ɗaya mai tsayi tare da faɗin layin ƙasa da 2 kHz. A cikin 2014, ƙungiyar ta yi amfani da ɗan gajeren rami na madaidaiciya (mai daidaitawa na folded ring resonator) haɗe tare da tacewa FBG-FP don samun fitowar laser tare da faɗin layi mai kunkuntar, kamar yadda aka nuna a cikin Hoto 3. A cikin 2012, Cai et al. yayi amfani da tsarin ɗan gajeren rami na 1.4cm don samun fitarwar laser mai polarizing tare da ikon fitarwa sama da 114mW, tsakiyar tsayin 1540.3 nm, da faɗin layi na 4.1 kHz. A cikin 2013, Meng et al. amfani da Brillouin watsawa na erbium-doped fiber tare da ɗan gajeren rami na zobe na cikakken na'urar adana son rai don samun yanayin tsayin daka guda ɗaya, ƙananan ƙararrakin ƙararrakin laser tare da ikon fitarwa na 10 mW. A cikin 2015, ƙungiyar ta yi amfani da rami na zobe wanda ya ƙunshi 45 cm erbium-doped fiber kamar yadda Brillouin watsawa ya sami matsakaici don samun ƙananan kofa da kunkuntar fitarwa na laser.
Hoto 2 (a) Zane-zane na SLC fiber Laser;
(b) Layin siginar heterodyne da aka auna tare da jinkirin fiber na 97.6 km
Lokacin aikawa: Nuwamba-20-2023