fasahar tushen Laser donZaren ganigane Kashi na Daya
Fasahar gane fiber optic wani nau'in fasahar gane fiber ne da aka haɓaka tare da fasahar sadarwa ta fiber optic da fasahar sadarwa ta fiber optic, kuma ta zama ɗaya daga cikin rassan fasahar photoelectric mafi aiki. Tsarin gane fiber optic galibi ya ƙunshi laser, fiber transmission, element sensing or modulation area, light detection da sauran sassa. Sigogi da ke bayyana halayen raƙuman haske sun haɗa da ƙarfi, tsawon rai, lokaci, yanayin polarization, da sauransu. Waɗannan sigogi na iya canzawa ta hanyar tasirin waje a cikin watsa fiber optic. Misali, lokacin da zafin jiki, matsin lamba, matsin lamba, motsi, girgiza, juyawa, lanƙwasawa da adadin sinadarai suka shafi hanyar gani, waɗannan sigogi suna canzawa daidai gwargwado. Sensing fiber optic ya dogara ne akan alaƙar da ke tsakanin waɗannan sigogi da abubuwan waje don gano adadin jiki masu dacewa.
Akwai nau'ikan iri da yawatushen laserana amfani da shi a tsarin firikwensin fiber na gani, wanda za'a iya raba shi zuwa rukuni biyu: mai haɗin kaiMajiyoyin Laserda kuma tushen haske mara daidaituwa, rashin daidaituwatushen haskegalibi sun haɗa da hasken incandescent da diodes masu fitar da haske, kuma tushen haske mai haɗawa sun haɗa da lasers masu ƙarfi, lasers na ruwa, lasers na gas,Laser na semiconductorkumaLaser ɗin fiberMafi yawancin waɗannan abubuwan an yi su ne dontushen hasken laserAna amfani da shi sosai a fannin gano zare a cikin 'yan shekarun nan: faɗin layi mai faɗi da kuma faɗin mita ɗaya, da kuma hasken laser mai tsawon zango ɗaya da kuma hasken laser fari.
1.1 Bukatu don faɗin layi mai kunkuntartushen hasken laser
Ba za a iya raba tsarin gane fiber na gani daga tushen laser ba, kamar yadda hasken da ke ɗauke da siginar da aka auna, aikin tushen hasken laser da kansa, kamar kwanciyar hankali, faɗin layin laser, hayaniyar lokaci da sauran sigogi akan nisan gano tsarin gano fiber na gani, daidaiton ganowa, yanayin ji da hayaniya suna taka muhimmiyar rawa. A cikin 'yan shekarun nan, tare da haɓaka tsarin gane fiber na gani mai nisa mai tsayi, masana kimiyya da masana'antu sun gabatar da ƙarin buƙatu masu tsauri don aikin faɗin layi na ƙaramin laser, galibi a cikin: fasahar hangen nesa na yanki na mitar gani (OFDR) tana amfani da fasahar ganowa mai daidaituwa don nazarin siginar da aka watsar da fiber na gani a cikin yankin mita, tare da ɗaukar hoto mai faɗi (dubban mita). Fa'idodin ƙuduri mai girma (ƙudurin matakin milimita) da babban ji (har zuwa -100 dBm) sun zama ɗaya daga cikin fasahohin da ke da fa'idodin aikace-aikace masu faɗi a cikin fasahar auna fiber na gani da aka rarraba. Babban fasahar OFDR shine amfani da tushen haske mai iya canzawa don cimma daidaitawar mitar gani, don haka aikin tushen laser yana ƙayyade mahimman abubuwan kamar kewayon gano OFDR, ji da gani da ƙuduri. Idan nisan wurin nuni ya kusa da tsawon haɗin kai, ƙarfin siginar bugun zai ragu sosai ta hanyar ma'aunin τ/τc. Ga tushen hasken Gaussian mai siffar spectral, don tabbatar da cewa mitar bugun tana da ganuwa fiye da 90%, alaƙar da ke tsakanin faɗin layin tushen haske da matsakaicin tsawon ji da tsarin zai iya cimmawa shine Lmax ~ 0.04vg/f, wanda ke nufin cewa ga zare mai tsawon kilomita 80, faɗin layin tushen haske bai wuce 100 Hz ba. Bugu da ƙari, haɓaka wasu aikace-aikace kuma yana gabatar da buƙatu mafi girma don faɗin layin tushen haske. Misali, a cikin tsarin hydrophone na fiber optical fiber, faɗin layin tushen haske yana ƙayyade hayaniyar tsarin kuma yana ƙayyade mafi ƙarancin siginar da za a iya aunawa na tsarin. A cikin Brillouin optical time reflector (BOTDR), ƙudurin auna zafin jiki da damuwa galibi ana ƙayyade shi ne ta hanyar faɗin layin tushen haske. A cikin gyro na fiber optic resonator, ana iya ƙara tsawon haɗin gwiwar raƙuman haske ta hanyar rage faɗin layin tushen hasken, ta haka ne za a inganta ƙanƙantar da zurfin resonator, rage faɗin layin resonator, da kuma tabbatar da daidaiton ma'aunin gyro na fiber optic.
1.2 Bukatun don hanyoyin laser masu gogewa
Laser mai ɗaukar tsawon tsayi ɗaya yana da aikin daidaita tsawon tsayi mai sassauƙa, yana iya maye gurbin lasers masu tsayi da yawa na fitarwa, rage farashin gina tsarin, wani muhimmin ɓangare ne na tsarin gane fiber optic. Misali, a cikin gano fiber gas, nau'ikan iskar gas daban-daban suna da kololuwar shaye-shaye daban-daban. Domin tabbatar da ingancin shaye-shaye lokacin da iskar ma'auni ta isa kuma ta sami ƙarfin aunawa mafi girma, ya zama dole a daidaita tsawon hasken watsawa tare da kololuwar shaye-shaye na ƙwayar iskar gas. Nau'in iskar da za a iya ganowa ana ƙaddara shi ta hanyar tsawon tsayin tushen hasken da ke ji. Saboda haka, ƙananan lasers masu faɗi tare da aikin daidaita broadband suna da sassauci mafi girma a cikin irin waɗannan tsarin ji. Misali, a cikin wasu tsarin jiye-jiye na fiber optic da aka rarraba bisa ga nunin yanki na mitar gani, ana buƙatar a share laser cikin sauri lokaci-lokaci don cimma babban daidaiton ganowa da kuma rage siginar gani, don haka ƙimar daidaitawa na tushen laser yana da buƙatu masu yawa, kuma ana buƙatar saurin share laser mai daidaitawa don isa 10 pm/μs. Bugu da ƙari, ana iya amfani da na'urar laser mai faɗi mai faɗi mai tsayi da za a iya canzawa a tsawon tsayi a cikin liDAR, na'urar hangen nesa ta laser da kuma na'urar nazarin spectral mai ƙuduri mai girma da sauran fannoni na ji. Domin biyan buƙatun manyan sigogi na daidaita bandwidth, daidaiton daidaitawa da saurin daidaita lasers mai tsayi ɗaya a fannin jifar fiber, babban burin nazarin na'urorin lasers mai faɗi mai faɗi da za a iya gyarawa a cikin 'yan shekarun nan shine cimma daidaito mai girma a cikin kewayon tsayi mai girma bisa ga bin layin laser mai faɗi mai faɗi, hayaniyar mataki mai ƙarancin ƙarfi, da kuma mita da ƙarfi mai ƙarfi.
1.3 Bukatar tushen hasken laser mai launin fari
A fannin na'urar hangen nesa ta gani, na'urar hangen nesa ta haske mai inganci tana da matuƙar muhimmanci wajen inganta aikin tsarin. Yayin da faɗin hasken laser na haske mai haske ya fi yawa, haka nan amfani da shi a tsarin na'urar hangen nesa ta fiber optic. Misali, lokacin amfani da fiber Bragg grating (FBG) don gina hanyar sadarwa ta firikwensin, ana iya amfani da na'urar nazarin haske ko hanyar daidaita matattara don rage haske. Na'urar ta yi amfani da na'urar auna haske don gwada kowace tsayin sautin FBG a cikin hanyar sadarwa. Na'urar tana amfani da matattara ta tunani don bin diddigin da daidaita FBG a cikin na'urar hangen nesa, duka biyun suna buƙatar tushen hasken broadband a matsayin tushen hasken gwaji ga FBG. Saboda kowace hanyar sadarwa ta FBG za ta sami asarar sakawa, kuma tana da bandwidth fiye da 0.1 nm, rage haske na FBG da yawa a lokaci guda yana buƙatar tushen hasken broadband mai ƙarfi da babban bandwidth. Misali, lokacin amfani da grating na fiber na dogon lokaci (LPFG) don ganewa, tunda bandwidth na kololuwar asara ɗaya yana cikin tsari na 10 nm, ana buƙatar tushen haske mai faɗi tare da isasshen bandwidth da kuma lebur mai faɗi don siffanta halayen kololuwar resonant ɗinsa daidai. Musamman ma, grating na acousto-optical (AIFG) wanda aka gina ta amfani da tasirin acousto-optical zai iya cimma kewayon daidaitawa na tsawon resonant har zuwa 1000 nm ta hanyar daidaita wutar lantarki. Saboda 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 grating na Bragg fiber mai karkata sosai a fannin gane fiber. Saboda halayensa na asarar kololuwar yawa, kewayon rarrabawar tsawon rai yawanci zai iya kaiwa 40 nm. Tsarin ji da shi yawanci shine don kwatanta motsin dangi tsakanin kololuwar watsawa da yawa, don haka ya zama dole a auna bakan watsa shi gaba ɗaya. Ana buƙatar bandwidth da ƙarfin tushen haske mai faɗi su zama mafi girma.
2. Matsayin bincike a gida da waje
2.1 Madogarar hasken laser mai faɗi da faɗi
2.1.1 Laser mai ratsawa mai faɗi da faɗi na semiconductor mai ratsawa
A shekara ta 2006, Cliche da abokan aikinsa sun rage ma'aunin MHz na semiconductor.Laser DFB(rarraba laser feedback) zuwa sikelin kHz ta amfani da hanyar amsawar lantarki; A cikin 2011, Kessler et al. sun yi amfani da ƙaramin zafin jiki da babban kwanciyar hankali na lu'ulu'u ɗaya tare da sarrafa amsawar aiki don samun fitowar laser mai faɗi na 40 MHz; A cikin 2013, Peng et al. sun sami fitowar laser semiconductor tare da faɗin layi na 15 kHz ta amfani da hanyar daidaitawar amsawar Fabry-Perot (FP) na waje. Hanyar mayar da martanin lantarki galibi ta yi amfani da martanin daidaita mitar Pond-Drever-Hall don rage faɗin layin laser na tushen haske. A cikin 2010, Bernhardi et al. sun samar da 1 cm na alumina FBG na erbium-doped akan wani silicon oxide substrate don samun fitarwa laser tare da faɗin layi na kusan 1.7 kHz. A cikin wannan shekarar, Liang et al. ya yi amfani da martanin allurar kai na Rayleigh warwatsewar baya da aka samar ta hanyar resonator mai girman Q echo bango don matse layin laser na semiconductor, kamar yadda aka nuna a Hoto na 1, kuma a ƙarshe ya sami fitowar laser mai faɗi na layi na 160 Hz.
Hoto na 1 (a) Zane na matsewar layin laser na semiconductor bisa ga watsawar Rayleigh ta hanyar allurar kai ta hanyar amfani da na'urar resonator ta yanayin raɗawa ta waje;
(b) Mitar mita na laser semiconductor mai gudana kyauta tare da faɗin layi na 8 MHz;
(c) Mitar mitar laser tare da matse faɗin layi zuwa 160 Hz
2.1.2 Laser ɗin fiber mai faɗi mai faɗi
Ga na'urorin laser na fiber na ramin layi, ana samun fitowar laser mai faɗi mai faɗi na yanayin tsayi ɗaya ta hanyar rage tsawon resonator da ƙara tazara tsakanin yanayin tsayi. A shekara ta 2004, Spiegelberg da abokan aikinsa sun sami fitowar laser mai faɗi mai faɗi ɗaya na yanayin tsayi tare da faɗin layi na 2 kHz ta amfani da hanyar DBR ta gajeren rami. A shekara ta 2007, Shen da abokan aikinsa sun yi amfani da zare mai silikon erbium mai tsawon santimita 2 don rubuta FBG akan zaren photosensitive na Bi-Ge, kuma sun haɗa shi da zare mai aiki don samar da ƙaramin rami mai layi, wanda hakan ya sa faɗin layin fitarwa na laser ɗinsa ya zama ƙasa da 1 kHz. A shekara ta 2010, Yang da abokan aikinsa sun yi amfani da gajeriyar rami mai faɗi mai faɗi mai tsawon santimita 2 tare da matattarar FBG mai faɗi don samun fitowar laser mai faɗi ɗaya na yanayin tsayi tare da faɗin layi ƙasa da 2 kHz. A shekarar 2014, ƙungiyar ta yi amfani da wani ɗan gajeren rami mai layi (mai lanƙwasa zobe mai kama-da-wane) tare da matattarar FBG-FP don samun fitowar laser tare da faɗin layi mai kunkuntar, kamar yadda aka nuna a Hoto na 3. A shekarar 2012, Cai et al. sun yi amfani da tsarin rami mai 1.4cm don samun fitowar laser mai polarizing tare da ƙarfin fitarwa sama da 114 mW, tsawon tsayin tsakiya na 1540.3 nm, da faɗin layi na 4.1 kHz. A shekarar 2013, Meng et al. sun yi amfani da watsawar Brillouin na zare mai erbium tare da ɗan gajeren ramin zobe na na'urar kiyaye cikakken bias don samun yanayin laser mai tsayi ɗaya, ƙaramin lokaci mai ƙaran ƙarfi tare da ƙarfin fitarwa na 10 mW. A shekarar 2015, ƙungiyar ta yi amfani da ramin zobe wanda ya ƙunshi zare mai erbium mai 45 cm a matsayin matsakaicin gain na watsawar Brillouin don samun ƙarancin iyaka da kuma fitowar laser mai faɗi mai faɗi.
Hoto na 2 (a) Zane-zanen tsarin laser na fiber na SLC;
(b) Siffar layi ta siginar heterodyne da aka auna da jinkirin zare na kilomita 97.6
Lokacin Saƙo: Nuwamba-20-2023