Basic pfungwa ye optical fiber kutaurirana.
An optical fiber is dielectric optical waveguide, waveguide chimiro chinovhara chiedza uye kuparadzira chiedza muaxial direction.
Yakanyanya kunaka fiber yakagadzirwa negirazi requartz, synthetic resin, nezvimwe.
Single mode faibha: musimboti 8-10um, cladding 125um
Multimode faibha: musimboti 51um, cladding 125um
Nzira yekufambisa yekufambisa zviratidzo zveoptical fibers inonzi optical fiber communication.
Masaisai emwenje ndeechikamu chemagetsi emagetsi.
Kureba kwechiedza chinooneka 390-760 nm, chikamu chikuru kupfuura 760 nm infrared light, uye chikamu chidiki pane 390 nm iultraviolet mwenje.
Chiedza chekushanda hwindo (mahwindo matatu ekutaurirana):
Iyo wavelength renji inoshandiswa mufiber-optic kutaurirana iri munharaunda iri pedyo-infrared
Ipfupi-wavelength dunhu (chiedza chinooneka, chiri mwenje orenji neziso rakashama) 850nm orenji mwenje
Yakareba wavelength dunhu (isingaonekwe mwenje nharaunda) 1310 nm (theoretical zvishoma dispersion point), 1550 nm (iyo theoretical yakaderera attenuation point)
Fiber chimiro uye kupatsanura
1.Chimiro chefiber
Iyo yakakodzera fiber chimiro: core, cladding, coating, jekete.
Iyo yepakati uye yekupfekedza inogadzirwa neiyo quartz zvinhu, uye michina yemagetsi haina kusimba uye iri nyore kutyora.Naizvozvo, maviri akaturikidzana ekuputira layer, imwe resin rudzi uye imwe layer yerudzi rwenaironi inowanzowedzerwa, kuitira kuti kuchinjika kuita kwefiber kusvike kune zvinoshanda zvekushandisa zvinodiwa zvepurojekiti.
2.Kuronga kwe optical fibers
(1) Iyo fiber inopatsanurwa maererano nerefractive index kugoverwa kwechikamu chemuchinjiko wefiber: inokamurwa kuita nhanho mhando fiber (uniform fiber) uye graded fiber (isina-uniform fiber).
Fungidzira kuti iyo yakakosha ine refractive index ye n1 uye iyo cladding refractive index ndeye n2.
Kuti uite kuti musimboti utumire mwenje pamakiromita marefu, mamiriro anodiwa ekuvaka iyo optical fiber ndeye n1> n2.
Iyo refractive index distribution yeuniform fiber inogara iripo
Iyo refractive index yekugovera mutemo weiyo isiri-uniform fiber:
Pakati pavo, △ - hama refractive index musiyano
Α-refractive index, α=∞-step-type refractive index distribution fiber, α=2-square-law refractive index distribution fiber (a graded fiber).Fiber iyi inofananidzwa nemamwe magraded fibers.Mode dispersion minimum optimal.
(1) Zvinoenderana nehuwandu hwemamodhi anofambiswa mukati mepakati: yakakamurwa kuita multimode fiber uye single mode fiber.
Patani pano inoreva kugoverwa kwemagetsi emagetsi echiedza chinofambiswa mune optical fiber.Kugoverwa kwemunda kwakasiyana kune nzira yakasiyana.
Single mode (imwe chete modhi inofambiswa mufiber), multimode (mamodhi akawanda anofambiswa panguva imwe chete mufiber)
Parizvino, nekuda kwekuwedzera kwezvinodiwa pachiyero chekutapurirana uye kuwedzera kwenhamba yekutapurirana, iyo metropolitan nzvimbo network iri kusimukira munzira yekumhanya kukuru uye hukuru hukuru, saka mazhinji acho ari single mode stepped fibers.(Maitiro ekutapurirana ega ari nani pane multimode fiber)
(2) Hunhu hwe optical fiber:
①Kurasika hunhu hwefiber optical: Mafungu emwenje anofambiswa mune optical fiber, uye simba rekuona rinodzikira zvishoma nezvishoma sezvo kureba kwekufambisa kunowedzera.
Zvikonzero zvekurasika kwefiber zvinosanganisira: kubatanidza kurasikirwa, kurasikirwa nekunyura, kurasikirwa kwekuparadzira, uye kubhenda kurasikirwa nemwaranzi.
Kubatana kurasikirwa kurasikirwa kunokonzerwa nekubatana pakati pefiber uye mudziyo.
Kurasikirwa kwekunyura kunokonzerwa nekutorwa kwesimba rechiedza ne fiber zvinhu uye tsvina.
Iko kurasikirwa kwekuparadzira kwakakamurwa kuita Rayleigh kuparadzira (refractive index non-uniformity) uye waveguide kuparadzira (kusaenzana kwezvinhu).
Iko kubhenda kwemwaranzi kurasikirwa ndiko kurasikirwa kunokonzerwa nekukotama kwefiber inotungamira kune radiation modhi inokonzerwa nekukotama kwefiber.
②Kupararira maitiro e optical fiber: Zvikamu zvakasiyana-siyana muchiratidzo chinoparadzirwa nefiber optical zvine zvakasiyana-siyana zvekufambisa, uye chiitiko chepanyama chekukanganiswa kunokonzerwa nechiratidzo chekuputika kana kusvika kumugumo kunonzi dispersion.
Kupararira kwakakamurwa kuita modal dispersion, material dispersion, uye waveguide dispersion.
Basic components of optical fiber communication systems
Tumira chikamu:
Iyo pulse modulation siginecha inoburitswa nemagetsi transmitter (yemagetsi terminal) inotumirwa kune optical transmitter (iyo chiratidzo chinotumirwa nechirongwa-inodzorwa switch inogadziriswa, waveform yakaumbwa, inverse yepati inoshandurwa… kuita chiratidzo chemagetsi chakakodzera. uye kutumirwa kune optical transmitter)
Basa rekutanga reiyo optical transmitter ndere kushandura chiratidzo chemagetsi kuita chiratidzo chemaziso chinosanganiswa mufiber.
Kugamuchira chikamu:
Kushandura zviratidzo zvemaziso zvinotapurirwa kuburikidza neoptical fibers kuva zviratidzo zvemagetsi
Kugadziriswa kwechiratidzo chemagetsi kunodzoserwa kune yekutanga pulse modulated siginecha uye inotumirwa kune yemagetsi terminal (chiratidzo chemagetsi chinotumirwa neanogamuchira chinogadziriswa chinogadziriswa, waveform yakaumbwa, iyo inverse yemuenzaniso inopindurwa ... yakadzoserwa kune programmable switch)
Transmission chikamu:
Single-modhi faibha, optical repeater (yemagetsi regenerative repeater (optical-electric-optical conversion amplification, kutapurirana kunonoka kuchave hombe, pulse decision circuit ichashandiswa kuumba waveform, uye nguva), erbium-doped fiber Amplifier (inopedzisa kukwidziridzwa. padanho rekuona, pasina waveform kuumbwa)
(1) Optical transmitter: Iyo transceiver yemaziso inoziva kutendeuka kwemagetsi / optical.Iyo ine mwenje sosi, mutyairi uye modulator.Basa racho nderekumisa mwenje wave kubva kumushini wemagetsi kuenda kune mwenje wave unoburitswa nemwenje sosi kuti ive yakadzimwa, uye wozobatanidza iyo modulated optical siginecha kune optical fiber kana optical tambo yekutapurirana.
(2) Optical receiver: is an optical transceiver inoona shanduko yemagetsi / yemagetsi.Iyo utility modhi inoumbwa nemwenje inoona sedunhu uye yemeso amplifier, uye basa nderekushandura chiratidzo chemaziso chinofambiswa neoptical fiber kana optical tambo kuita chiratidzo chemagetsi neiyo optical detector, uye wobva wakudza iyo isina simba chiratidzo chemagetsi kuti chiyero chakakwana kuburikidza nedunhu rekusimudzira kutumirwa kune chiratidzo.Mhedziso yekugamuchira yemuchina wemagetsi inoenda.
(3) Fiber / Cable: Fiber kana tambo inoumba nzira yekufambisa yechiedza.Basa racho nderokutumira chiratidzo chakasvibiswa chinotumirwa nekuguma kwekutumira kune optical detector yekuguma kwekugamuchira mushure mekufamba-kure-kure kuburikidza ne optical fiber kana optical cable kupedzisa basa rekutumira mashoko.
(4) Optical repeater: ine photodetector, chiedza sosi, uye sarudzo yekuvandudza dunhu.Kune mabasa maviri: imwe ndeyekubhadhara kuderedzwa kwechiratidzo chemaziso chinoparidzirwa mufiber optical;imwe yacho ndeyekugadzira kupuruzira kwe waveform distortion.
(5) Passive zvikamu zvakadai sefiber optic connectors, couplers (hapana chikonzero chekupa simba zvakasiyana, asi mudziyo uchiri kurasikirwa): Nekuti kureba kwefiber kana tambo kunogumirwa neiyo fiber kudhirowa maitiro uye tambo yekuvaka mamiriro, uye iyo kureba kwefaibha zvakare Limit (eg 2km).Naizvozvo, panogona kunge paine dambudziko rekuti kuwanda kwemafiber optical akabatana mune imwe optical fiber line.Naizvozvo, kuwirirana pakati pe optical fibers, kubatana uye kubatanidza kwe optical fibers uye optical transceivers, uye kushandiswa kwezvinhu zvisingaoneki zvakadai se optical connectors uye couplers inokosha.
Kukwirira kwe optical fiber communication
Transmission bandwidth, yakakura kutaurirana kugona
Yakaderera kutapurirana kurasikirwa uye yakakura relay kureba
Kupindira kwakasimba kwe-anti-electromagnetic
(Kunze kwewireless: masaini masaini ane akawanda mhedzisiro, mabhenefiti akawanda, mumvuri mhedzisiro, Rayleigh kupera, Doppler mhedzisiro.
Kuenzaniswa necoaxial tambo: chiratidzo chemaziso chakakura pane coaxial tambo uye ine kuvanzika kwakanaka)
Iyo frequency yemwenje wave yakakwira zvakanyanya, zvichienzaniswa nemamwe masaisai emagetsi, kupindira kudiki.
Kuipa kweiyo optical tambo: isina kunaka mechanical zvivakwa, nyore kuputsika, (kunatsiridza mashandiro emakanika, ichave nemhedzisiro yekukanganisa kuramba), zvinotora nguva yakareba kuvaka, uye zvinokanganiswa nemamiriro enzvimbo.