Namuhla, sizokwethula i-laser “e-monochromatic” ngokwedlulele – i-laser encane enobubanzi obuncane. Ukuvela kwayo kugcwalisa izikhala emikhakheni eminingi yokusetshenziswa kwe-laser, futhi eminyakeni yamuva nje isetshenziswe kabanzi ekutholeni amagagasi adonsela phansi, i-liDAR, i-distributed sensing, ukuxhumana kwe-optical okunesivinini esikhulu kanye neminye imikhakha, okuwumsebenzi “ongenakuqedwa kuphela ngokuthuthukisa amandla e-laser.
Iyini i-laser encane enobubanzi bomugqa?
Igama elithi “ububanzi bomugqa” libhekisela kububanzi bomugqa we-spectral we-laser kusizinda semvamisa, okuvame ukubalwa ngokwesilinganiso sobubanzi obugcwele be-spectrum (FWHM). Ububanzi bomugqa buthintwa kakhulu yimisebe ezenzakalelayo yama-athomu noma ama-ion avuselelwe, umsindo wesigaba, ukudlidliza komshini we-resonator, i-temperature jitter nezinye izinto zangaphandle. Uma inani lobubanzi bomugqa lincane, kulapho ubumsulwa be-spectrum buphakama khona, okungukuthi, i-monochromaticity ye-laser iba ngcono. Ama-Laser anezici ezinjalo ngokuvamile anomsindo omncane kakhulu wesigaba noma wemvamisa kanye nomsindo omncane kakhulu wokuqina okuhlobene. Ngesikhathi esifanayo, uma inani lobubanzi obuqondile be-laser lincane, kulapho ukuhambisana okuhambisanayo kuqina khona, okubonakaliswa njengobude bokuhambisana obude kakhulu.
Ukuqashelwa kanye nokusetshenziswa kwe-laser encane yobubanzi bomugqa
Njengoba inqunyelwe ububanzi bokuthola okungokwemvelo kwento esebenzayo ye-laser, cishe akunakwenzeka ukubona ngqo umphumela we-laser encane yobubanzi ngokuthembela ku-oscillator yendabuko uqobo. Ukuze kuqashelwe ukusebenza kwe-laser encane yobubanzi, ngokuvamile kuyadingeka ukusebenzisa izihlungi, i-grating kanye namanye amadivayisi ukukhawulela noma ukukhetha i-modulus ende ku-gain spectrum, ukwandisa umehluko wenzuzo eningi phakathi kwezindlela ze-longitudinal, ukuze kube nokugoba okuncane noma okukodwa kuphela kwemodi ye-longitudinal ku-resonator ye-laser. Kule nqubo, kuvame ukudingeka ukulawula ithonya lomsindo ekuphumeni kwe-laser, nokunciphisa ukusabalala kwemigqa ye-spectral okubangelwa ukudlidliza nokushintsha kwezinga lokushisa kwendawo yangaphandle; Ngesikhathi esifanayo, ingahlanganiswa nokuhlaziywa kobuningi be-spectral yomsindo wesigaba noma imvamisa ukuqonda umthombo womsindo nokuthuthukisa ukwakheka kwe-laser, ukuze kufezwe umphumela ozinzile we-laser encane yobubanzi.
Ake sibheke ukuqashelwa kokusebenza kobubanzi obuncane bemigqa yezigaba eziningana ezahlukene zama-laser.
Ama-laser e-semiconductor anezinzuzo zobukhulu obuncane, ukusebenza kahle okuphezulu, impilo ende kanye nezinzuzo zomnotho.
I-resonator ye-Fabry-Perot (FP) esetshenziswa kwendabukoama-laser e-semiconductorngokuvamile iyashintshashintsha kumodi ye-multi-longitudinal, futhi ububanzi bomugqa wokukhipha bubanzi kakhulu, ngakho-ke kuyadingeka ukwandisa impendulo ye-optical ukuze uthole umphumela wobubanzi bomugqa omncane.
Impendulo Esabalalisiwe (i-DFB) kanye ne-Distributed Bragg reflection (i-DBR) yi-laser ezimbili ezijwayelekile ze-internal optical feedback semiconductor lasers. Ngenxa ye-grating pitch encane kanye nokukhetha okuhle kwe-wavelength, kulula ukufeza umphumela ozinzile we-single-frequency narrow linewidth. Umehluko omkhulu phakathi kwezakhiwo ezimbili yindawo ye-grating: isakhiwo se-DFB sivame ukusabalalisa isakhiwo se-periodic se-Bragg grating kuyo yonke i-resonator, futhi i-resonator ye-DBR ivame ukwakhiwa yisakhiwo se-reflection grating kanye nesifunda se-gain esihlanganiswe endaweni yokugcina. Ngaphezu kwalokho, ama-laser e-DFB asebenzisa ama-embedded gratings anomehluko we-refractive index ophansi kanye nomehluko we-reflectivity ophansi. Ama-laser e-DBR asebenzisa ama-surface gratings anomehluko we-refractive index ophakeme kanye nomehluko we-reflectivity ophakeme. Zombili izakhiwo zinebanga elikhulu le-free spectral futhi zingenza ukulungiswa kwe-wavelength ngaphandle kokushintsha kwemodi ebangeni lama-nanometer ambalwa, lapho i-DBR laser inobubanzi bokuhlela obubanzi kune-I-laser ye-DFBNgaphezu kwalokho, ubuchwepheshe bempendulo yokukhanya yesikhala sangaphandle, obusebenzisa izakhi zokukhanya zangaphandle ukuphendula ukukhanya okuphumayo kwe-chip ye-laser ye-semiconductor nokukhetha imvamisa, bungaphinde bufeze ukusebenza kobubanzi obuncane be-laser ye-semiconductor.
(2) Ama-laser e-fiber
Ama-laser e-fiber anokusebenza kahle kokuguqulwa kwephampu ephezulu, ikhwalithi enhle ye-beam kanye nokusebenza kahle kokuxhuma okuphezulu, okuyizihloko zocwaningo ezishisayo emkhakheni we-laser. Ngokomongo wenkathi yolwazi, ama-laser e-fiber anokuhambisana okuhle nezinhlelo zokuxhumana ze-optical fiber zamanje emakethe. I-laser ye-fiber enemvamisa eyodwa enezinzuzo zobubanzi bomugqa omncane, umsindo ophansi kanye nokuhambisana okuhle isibe ngenye yezinkomba ezibalulekile zentuthuko yayo.
Ukusebenza kwemodi eyodwa ye-longitudinal kuyisisekelo se-fiber laser ukuze kufezwe umphumela wobubanzi bomugqa omncane, ngokuvamile ngokwesakhiwo se-resonator, i-single frequency fiber laser ingahlukaniswa ngohlobo lwe-DFB, uhlobo lwe-DBR kanye nohlobo lwendandatho. Phakathi kwazo, isimiso sokusebenza se-DFB kanye ne-DBR single-frequency fiber lasers sifana nese-DFB kanye ne-DBR semiconductor lasers.
Njengoba kuboniswe kuMfanekiso 1, i-laser yefayibha ye-DFB izobhala i-Bragg grating esakazwe ku-fiber. Ngenxa yokuthi ubude be-wavelength obusebenzayo be-oscillator buthintwa yisikhathi sefayibha, imodi ye-longitudinal ingakhethwa ngempendulo esakazwe ye-grating. I-resonator ye-laser ye-DBR laser ivame ukwakheka yi-pair ye-fiber Bragg gratings, kanti imodi ye-longitudinal eyodwa ikhethwa kakhulu yi-band encane kanye ne-reflectivity ephansi yefayibha ye-Bragg gratings. Kodwa-ke, ngenxa ye-resonator yayo ende, isakhiwo esiyinkimbinkimbi kanye nokuntuleka kwendlela ephumelelayo yokuhlukanisa imvamisa, i-cavity efana nendandatho ithambekele ekushintsheni kwemodi, futhi kunzima ukusebenza ngokuzinzile kwimodi ye-longitudinal engaguquki isikhathi eside.
Umfanekiso 1, Izakhiwo ezimbili ezijwayelekile eziqondile zemvamisa eyodwaama-laser efayibha
Isikhathi sokuthunyelwe: Novemba-27-2023