Ukulahlekelwa ukugoba kwefayibha kubhekisela ekulahlekelweni kwesignali okwenzeka lapho i-optical fiber igobile ngale kwe-radius ethile. Lesi simo sibangelwa ukuvuza kokukhanya okuvela enkabeni ye-fiber njengoba ihamba nge-cladding. Lapho i-fiber igobile, imisebe yokukhanya idlula ekukhanyeni kwangaphakathi okuphelele ku-interface ye-core-cladding. Kodwa-ke, uma i-radius egobile incane kakhulu, eminye yemisebe yokukhanya ingaphuma nge-cladding, okuholela ekulahlekelweni.

Ukulahlekelwa kwe-fiber ukugoba kuncike ezintweni eziningana:

Irediyasi Egobayo: Uma i-radius yokugoba incane, kulapho ukulahlekelwa kokugoba kukhuphuka khona. Lokhu kungenxa yokuthi i-radius encane yokugoba ibangela ukuthi imisebe yokukhanya ibhekane nokugoba okukhulu, okwandisa amathuba okuvuza nge-cladding.

Uhlobo lwefayibha: Izinhlobo ezahlukene zemicu zinezimpawu zokulahlekelwa ukugoba ezihlukene. Isibonelo, imicu yemodi eyodwa ivame ukuba nokulahlekelwa okuphansi kokugoba uma kuqhathaniswa nemicu yemodi eminingi.

Ubude bamagagasi: Ukulahleka kokugoba kungahlukahluka ngokwesilinganiso sobude bokukhanya okudluliselwa ngefayibha. Amanye ama-wavelength angase abhekane nokulahlekelwa okukhulu kokugoba kunezinye.

Umklamo wefayibha: Ukwakheka kwefayibha, okuhlanganisa iphrofayili yenkomba yokubuyisa kanye nezinto ezisetshenziswayo, kungathinta ukulahleka kokugoba.

Ukugqoka: Uhlobo kanye nekhwalithi yengubo esetshenziswa ku-fiber kungathinta ukuguquguquka kwayo kanye nokumelana nokulahlekelwa ukugoba.

Ukuze unciphise ukulahlekelwa ukugoba, kubalulekile ukuphatha imicu ye-optical ngokucophelela futhi ugweme ukugoba ngokweqile, ikakhulukazi ukugoba okubukhali. Izintambo ze-fibre optic zivame ukuklanywa ngezingqimba zokuvikela kanye nokuqinisa ukuze kuncishiswe ukulahlekelwa ukugoba nokuqinisekisa ukudluliswa okuthembekile kwezimpawu.

Ekusetshenzisweni kwe-fiber optical, uhlobo oluyinkimbinkimbi kakhulu lokulahlekelwa yi-optical ukulahlekelwa yi-micro-gonding. Ngokuthuthuka kwamadivayisi kanye ne-fiber optical, ukulahlekelwa yi-micro-gonding kuyisici sokulahlekelwa esibaluleke kakhulu. Ukushintsha okuqondile kwe-optical kungeniswa kudivayisi esikhundleni sokushintsha kukagesi, futhi i-fiber isengozini yokucindezeleka isikhathi eside endaweni encane kakhulu. Ku-fiber, i-fiber encane, i-fiber encane yobubanzi, kungaba ngokunciphisa ubukhulu bengubo, noma ngokunciphisa ububanzi be-cladding; Ngokufanayo nakuma-fiber amaningi, ukujiya kwe-cladding okusebenzayo nakho kuzoncishiswa kakhulu, okwandisa ingozi yokulahlekelwa yi-micro-gonding.

Ukulahlekelwa yi-micro-bending kanye nokulahlekelwa yi-macro-bending kuhlobene nokugoba ngokoqobo, kodwa kunomehluko osobala phakathi kwazo ngokombono wendlela yokulahleka okwenzeka ngayo. Ngakho-ke, ekusetshenzisweni okungokoqobo, kubaluleke kakhulu ukuhlukanisa ukulahlekelwa kusuka ku-micro bend noma i-macro bend ngokwesimo sokulahlekelwa, okubandakanya indawo efanele yenkinga kanye nendlela yokuxazulula inkinga.

1. Ngokuphathelene nokuguqulwa kwejometri

Ukulahleka kokugoba okuncane empeleni kuwukulahlekelwa okulethwa ukugoba okuncane kwefayibha, kuyilapho ukulahlekelwa kokugoba okukhulu kuwukulahlekelwa okulethwa ukugoba kwangempela, kanti ububanzi bangaphandle befayibha buhlala buyinto efanelekile. Lokhu kwenza umehluko ocacile ku-geometry. Ukuguqulwa okuncane kwefayibha kungaphathwa njengokuphazanyiswa kwemvamisa ephezulu komjikelezo wejiyometri ohlangothini olude lwefayibha. Lokhu kugoba kunezimfanelo ezimbili: ubukhulu kanye nobuningi. Indawo yokugoba okuncane ivela emvamisa ephezulu kanye nobukhulu obuphansi. Ukuphazamiseka kwangaphandle kungalingiswa, futhi ubukhulu bayo kanye nobukhulu kushintsha ngokungahleliwe ngokuhamba kwesikhathi. Uma kuthathwa ukuguqulwa kwe-Fourier kwalokhu kuhlukahluka okungahleliwe, ubukhulu bulingana namandla, futhi kukhona ukuxhumana okuhambisanayo phakathi kobuningi be-spectral yamandla kanye nobuningi bendawo.

Lokhu kulula futhi ukukuqonda ngokwemvelo nokufinyelela esiphethweni esifanelekile: lapho imvamisa yokuphazamiseka iphezulu kakhulu, ukuguquguquka kwefayibha kuyafana, futhi ithonya lokulahlekelwa yi-micro-gonding alilikhulu. Kodwa-ke, lapho imvamisa yokuphazamiseka iphansi kakhulu, ukugoba kwangempela kungakheka, futhi ukulahlekelwa yi-macro-gonding kuba namandla.

2. Kusukela endleleni yokulahlekelwa

Ekulahlekelweni kokugoba okukhulu, kungacatshangwa ukuthi ukusatshalaliswa kwensimu yemodi yemodi eyisisekelo (i-fiber yemodi eyodwa) ku-fiber kuyasakazeka ohlangothini lokugoba, kanti ingxenye esakazeka ngokujulile ngaphakathi kwe-cladding izokwakha imisebe futhi ilahleke kancane kancane. Ekulahlekelweni kokugoba okuncane, ingxenye yamandla emodi eyisisekelo esakazeka ku-fiber efanele ihlanganiswa nezindlela ezahlukahlukene ze-oda eliphezulu ngaphansi kwesimo sokuphazamiseka. Njengoba ibanga lokusakazeka landa, amandla athwalwa yilezi zindlela ze-oda eliphezulu akhishwa ku-fiber ye-Oran yezingxenye eziyishumi, futhi-ke ingahlanganiswa kabusha ibuyele kumodi eyisisekelo.

Ukuhlaziywa kokulahlekelwa kwe-micro-bending ngokuvamile kusekelwe kumbono wokuxhumanisa imodi, futhi ubudlelwano obuyisisekelo buyinkimbinkimbi kancane.

Lapho i-C iyi-coefficient yokuxhumanisa phakathi kwemodi eyisisekelo kanye nenye yezindlela ze-high-order, okubonisa ukuthi angakanani amandla azohlanganiswa kusukela kumodi eqondisiwe kuya kumodi ye-high-order noma imodi ye-cladding (isimo semodi eyodwa). I-Qfiber ukuphazamiseka kwe-fiber ngaphansi kokucindezeleka okuqondile, kanti i-Qenv ukuphazamiseka ngaphansi kokucindezeleka okungaqondile lapho indawo ishintsha. Ukunemba kwalokhu kuhlaziywa kwemodeli kunzima ngoba ukuphazamiseka okubangela ukulahlekelwa kwe-micro-bending kungavamile kakhulu, kodwa inhloso yokuhlaziya ukunikeza umhlahlandlela oqinile, futhi kwezinye izimo, ama-coefficient engeziwe angasetshenziswa ukulinganisa imiphumela yokulingisa.

u-olshansky wafunda futhi waphakamisa ubudlelwano bokubuka esigabeni sokuqala.

irediyasi engu-a-core

b - Irediyasi yokumboza

Umehluko we-Delta - refractive index

I-modulus enwebekayo yengubo ye-EE-polymer

Isib. I-modulus ye-Elastic yengilazi ye-optical fiber

Ezimweni eziningi zokusetshenziswa, lobu budlelwano buwusizo kakhulu

3. Umthombo wokulahlekelwa yi-micro-goling

Umthombo wokulahlekelwa yi-micro-going ikakhulukazi yizinto zangaphandle. Uma i-fiber isetshenziswa kuphela njenge-fiber engenalutho ngaphandle kokwakheka kwekhebula, uma kungekho mandla angaphandle esikhaleni esikhululekile, akukho nokwenzeka kokulahlekelwa yi-micro-going. Nakuba ukungalingani kwe-geometric kwe-fiber ngokwayo kungaba nokwenzeka kokulahlekelwa yi-micro-going, ithonya lokulahlekelwa yi-micro-going ye-fiber ngokwayo linganganakwa ngoba ukuhlolwa kokulahlekelwa kuphasisiwe esivivinyweni sasefektri. Kubheka kuphela ithonya lokulahlekelwa yi-micro-going ye-fiber optical okuhambisana nokuqina kwangaphandle kukhebula noma idivayisi ye-optical.

Imithombo yokulahlekelwa yi-micro-bending ivela kakhulu ezicini ezintathu

Okokuqala ukwakheka kwefayibha uqobo. Ukwakheka kwefayibha ngokwayo akuyona imbangela yokulahleka kokugoba okuncane, kodwa ukuzwela kokugoba okuncane kunqunywa ukwakheka kwefayibha uqobo. Ukwakheka kwe-fiber core kuthonywa kakhulu yinani le-MAC. Lokhu kuhambisana nefomula yesici sika-Olshansky.

Uma i-MAC incane, ukulahlekelwa kwe-micro-bending kuzoba kuncane ngaphansi kokuphazamiseka kwangaphandle okufanayo.

Lokhu kubonakala ku-fiber ethile, ngokuvamile i-fiber ye-G657 inokulahlekelwa okuncane kokugoba kwe-micro kune-fiber ye-G652 ·

Nakuba ukunciphisa i-core radius nokwandisa umehluko we-refractive index kunganciphisa ukulahleka kwe-micro-bending, ukuhlangana phakathi kwamapharamitha e-fiber kanye nokumiswa kwe-fiber akunakwenzeka ukuthi kube khona esimweni sokushintsha ipharamitha eyodwa kuphela kuyilapho ezinye zingashintshi. Kodwa lo mkhuba uyaqhubeka.

Ukwakheka kwe-cladding ku-fiber nakho kungaletha intuthuko. Ukuncika kwe-wavelength kokulahlekelwa yi-microbending kuyahlukahluka kakhulu lapho kufakwa umklamo othile we-groove ku-cladding.

Ukuncika kobude besikhathi bokulahlekelwa yi-microbending ye-fiber egobile esithombeni kuhluke kakhulu kokwe-fiber ejwayelekile. Ukuncika kobude besikhathi be-fiber ejwayelekile kulesi sithombe kungaphezu kancane kwedatha evamile, ikakhulukazi ku-fiber yomklamo ogobile lapho ukulahlekelwa kwayo kokugobile okuncane kuyisicaba. Lokhu kusho ukuthi indawo evamile yenkinga kanye nokuhlaziywa kwenkinga kudinga ukucabangela ukwakheka kwe-fiber, ngaphandle kwalokho ngokusekelwe kokuhlangenwe nakho kungadukisa. Ngamafuphi, ukwakheka kwe-fiber kuthuthukisa ukulahleka kwe-micro-bending, okuzuzisayo ezimweni ezithile.

Okwesibili, umthombo wokulahlekelwa yi-micro-gonding uhlobene ne-factor yekhebula le-optical fiber, okuyinto eyinkimbinkimbi kakhulu. Ubunzima bulele eqinisweni lokuthi kunezinhlobo eziningi kakhulu zekhebula le-optical fiber futhi ukwakheka kuhlukile kakhulu, kodwa kulula kakhulu ukucacisa uhlobo oluthile. Isici esijwayelekile ithonya lokumboza. Ngokwemvelo, kungaphethwa nangokuthi ukumboza, njengomugqa wokuqala wokuzivikela ukuvikela i-fiber, kudlala indima yokuqhuba ukucindezeleka okuphumelelayo. Uma ukumboza kusetshenziswa njengomsebenzi wokudlulisa ukucindezeleka, lapho i-modulus yangaphakathi ye-elastic incane khona futhi lapho i-modulus yangaphandle ye-elastic inkulu khona, inani lomsebenzi wokudlulisa ukucindezeleka lincane, futhi ithonya lokulahlekelwa yi-micro-gonding elihambisanayo nalo lincane. Uma ububanzi bokumboza bukhulu khona, kulapho ithonya lokulahlekelwa yi-micro-gonding lincane khona.

Ngokusobala, ububanzi obungu-900um buncane kakhulu kunokulahlekelwa yi-microbending kwe-fiber engu-250um. Kungaziwa futhi ukuthi ekwakhiweni okufanayo kwekhebula le-fiber optic, yize isikhala somsebenzi we-fiber engu-900um sincane, ngaphansi kwezimo ezijwayelekile, ukulahlekelwa kwayo yi-micro-bending kuncane kakhulu kukhebula.

Isici sesithathu umthelela wendawo lapho ikhebula likhona khona. Ngenxa yobunzima bokulahlekelwa yi-micro-gonding, ayikho indlela yokuhlola ejwayelekile njengamanje, futhi indlela yokuhlola enikezwe yi-IEC/TR62221 ivame ukusetshenziswa ngqo. Kunzima ukunquma ukuphazamiseka. Ngisho nasezindleleni ezithile zokuhlola, izindawo zokuhlola kanye nemishini yokuhlola, izindawo ezahlukene zokubeka zingase zibe nemiphumela ehlukene. Imiphumela yama-laboratory ahlukene kanye nezindlela zokuhlola ezahlukene ayikwazi ukuqhathaniswa ngqo, kodwa konke kuyiziqhathaniso ezisezingeni eliphezulu. Ngemiphumela yayo yokuhlolwa, idinga ukuhlolwa ngokwehlukana.