A yau, za mu gabatar da laser mai "monochromatic" zuwa matsanancin - kunkuntar layin layi. Fitowarsa tana cike gibin da ke cikin fannoni da yawa na aikace-aikacen laser, kuma a cikin 'yan shekarun nan an yi amfani da shi sosai a cikin gano raƙuman nauyi, liDAR, ganowar rarrabawa, sadarwa mai saurin haɗi da sauran fannoni, wanda "aikin" ne wanda ba za a iya kammala shi kawai ta hanyar inganta ƙarfin laser ba.
Menene kunkuntar laser mai faɗi mai layi?
Kalmar "faɗin layi" tana nufin faɗin layin haske na laser a cikin yankin mita, wanda yawanci ana ƙididdige shi dangane da rabin kololuwar cikakken faɗin bakan (FWHM). Faɗin layi galibi yana shafar ta hanyar radiation na atomatik ko ions masu motsawa, hayaniyar mataki, girgizar injina na resonator, girgizar zafin jiki da sauran abubuwan waje. Ƙaramin ƙimar faɗin layi, mafi girman tsarkin bakan, wato, mafi kyawun monochromaticity na laser. Lasers masu irin waɗannan halaye yawanci suna da ƙarancin hayaniyar mataki ko mita da ƙarancin hayaniyar ƙarfi. A lokaci guda, ƙaramin ƙimar faɗin layi na laser, mafi ƙarfi da haɗin kai, wanda ke bayyana a matsayin tsayin haɗin kai mai tsawo.
Fahimta da amfani da ƙananan laser mai faɗi
An iyakance shi da faɗin layin riba na kayan aiki na laser, kusan ba zai yiwu a cimma fitowar kunkuntar laser mai faɗi ta hanyar dogaro da oscillator na gargajiya ba. Domin a cimma aikin kunkuntar laser mai faɗi ta layi, yawanci yana da mahimmanci a yi amfani da matattara, grating da sauran na'urori don iyakance ko zaɓar modulus na tsayi a cikin kewayon riba, ƙara bambancin riba tsakanin yanayin tsayi, don haka akwai ƴan ko ma sau ɗaya kawai yanayin juyawa a cikin resonator na laser. A cikin wannan tsari, sau da yawa yana da mahimmanci a sarrafa tasirin hayaniya akan fitowar laser, da kuma rage faɗaɗa layukan haske da canjin yanayin zafi na muhallin waje ke haifarwa; A lokaci guda, ana iya haɗa shi da nazarin yawan hayaniyar lokaci ko mita don fahimtar tushen hayaniya da inganta ƙirar laser, don cimma ingantaccen fitarwa na kunkuntar laser mai faɗi ta layi.
Bari mu dubi yadda ake aiwatar da aikin kunkuntar layin layi na nau'ikan laser daban-daban.
Na'urorin laser na Semiconductor suna da fa'idodin ƙaramin girma, ingantaccen aiki, tsawon rai da fa'idodin tattalin arziki.
Ana amfani da na'urar resonator ta Fabry-Perot (FP) a cikin fasahar gargajiyaLasers na semiconductorYawanci yana juyawa a cikin yanayin tsayi da yawa, kuma faɗin layin fitarwa yana da faɗi kaɗan, don haka ya zama dole a ƙara ra'ayoyin gani don samun fitowar faɗin layi mai kunkuntar.
Ra'ayoyin da aka Rarraba (DFB) da Rarraba Bragg Reflect (DBR) sune na'urori biyu na laser na semiconductor na ciki na gani guda biyu. Saboda ƙaramin matakin grating da kuma zaɓin tsayi mai kyau, yana da sauƙi a sami tsayayyen fitowar layin mita ɗaya mai kunkuntar. Babban bambanci tsakanin tsarin biyu shine matsayin grating: tsarin DFB yawanci yana rarraba tsarin lokaci na Bragg grating a cikin resonator, kuma resonator na DBR yawanci yana ƙunshe da tsarin grating na gani da kuma yankin riba da aka haɗa a cikin saman ƙarshe. Bugu da ƙari, lasers na DFB suna amfani da gratings da aka saka tare da ƙarancin bambancin refractive da ƙarancin haske. Lasers na DBR suna amfani da gratings na saman tare da babban bambancin refractive da babban haske. Dukansu tsarin suna da babban kewayon spectral kyauta kuma suna iya yin gyaran tsayi ba tare da tsalle-tsalle na yanayi ba a cikin kewayon nanometers kaɗan, inda laser DBR yana da kewayon daidaitawa mafi faɗi fiye daLaser DFBBugu da ƙari, fasahar mayar da martani ga na'urar hangen nesa ta waje, wadda ke amfani da abubuwan gani na waje don mayar da martani ga hasken da ke fitowa daga guntuwar laser na semiconductor da kuma zaɓar mitar, za ta iya aiwatar da aikin laser na semiconductor mai faɗi kaɗan.
(2) Lasers na fiber
Laser ɗin fiber yana da ingantaccen juyar da famfo, ingancin hasken rana mai kyau da kuma ingantaccen haɗin kai, waɗanda sune batutuwan bincike masu zafi a fannin laser. A cikin yanayin zamanin bayanai, laser ɗin fiber yana da kyakkyawan jituwa da tsarin sadarwa na fiber na gani na yanzu a kasuwa. Laser ɗin fiber mai mita ɗaya tare da fa'idodin faɗin layi mai faɗi, ƙarancin hayaniya da kyakkyawan haɗin kai ya zama ɗaya daga cikin mahimman alkiblar ci gabansa.
Aikin yanayin tsayi ɗaya shine tushen fiber laser don cimma fitowar faɗin layi mai faɗi, yawanci bisa ga tsarin resonator na fiber laser mai mita ɗaya za a iya raba shi zuwa nau'in DFB, nau'in DBR da nau'in zobe. Daga cikinsu, ƙa'idar aiki na DFB da DBR fiber lasers mai mita ɗaya yayi kama da na DFB da DBR semiconductor lasers.
Kamar yadda aka nuna a Hoto na 1, za a rubuta Bragg grating mai rarrabawa a cikin zaren. Saboda tsawon ƙarfin oscillator yana shafar tsawon zaren, ana iya zaɓar yanayin tsayi ta hanyar ra'ayoyin da aka rarraba na grating. Yawancin lokaci ana samar da resonator na laser na DBR ta hanyar nau'ikan Bragg gratings guda biyu, kuma yanayin tsayi ɗaya galibi ana zaɓar shi ta hanyar kunkuntar band da ƙananan fiber na Bragg gratings. Duk da haka, saboda dogon resonator ɗinsa, tsarin rikitarwa da rashin ingantaccen tsarin bambance-bambancen mita, rami mai siffar zobe yana da saurin hawa yanayin, kuma yana da wuya a yi aiki da kyau a cikin yanayin tsayi na dogon lokaci.
Hoto na 1, Tsarin layi guda biyu na yau da kullun na mita ɗayana'urorin laser na fiber
Lokacin Saƙo: Nuwamba-27-2023