Chifukwa Fresnel zone

Fresnel zone - madera limene padziko phokoso kapena kuwala mafunde kuchita kuwerengetsera zotsatira mapindidwe akuwala phokoso kapena kuwala. njira ichi poyamba ntchito 1815 O.Frenel.

nkhani za m'mbiri

Augustin-Zhan Frenel (10.06.1788-14.07.1827) - French sayansi. Pamoyo wake kuphunzira katundu wa Optics thupi. Iye mu 1811 mchikakamizo cha E. Malus anayamba paokha kuphunzira sayansi, posakhalitsa anachita chidwi kafukufuku experimental m'munda wa Optics. Mu 1814, a "anapeza" mfundo ya kuwasokoneza, ndipo mu 1816 anawonjezera mfundo odziwika a Huygens, amene anayambitsa mfundo Mgwirizano ndi kuwasokoneza mafunde pulayimale. Mu 1818, kumanga pa ntchito, iye anayamba chiphunzitso cha mapindidwe akuwala kuwala. Iye anayambitsa mwambo wa kulingalira mapindidwe akuwala kuchokera m'mphepete, komanso dzenje zozungulira. Imachitika zatsopano, tsopano upamwamba, ndi biprism ndi bizerkalami wa kusokonezedwa kuwala. Mu 1821 iye anawatsimikizira mfundo za chikhalidwe yopingasa mafunde kuwala, 1823 anatsegula kugawanika zozungulira ndipo elliptical. Iye anafotokoza pamaziko a yoweyula zithunzi chromatic kugawanika, komanso kasinthasintha wa ndege ya kugawanika kuwala ndi birefringence. Mu 1823, iye anakhazikitsa malamulo a refraction ndi chinyezimiro cha kuwala pa amodzi lathyathyathya pamwamba pa TV awiri. Pamodzi ndi Jung ankaona mlengi wa Optics yoweyula. Kodi anayambitsa zipangizo zingapo kuwasokoneza, monga galasi kapena Fresnel biprism Fresnel. Gululi woyambitsa wa njira wachibadidwe latsopano la nyumba zowunikira.

A pang'ono chiphunzitso

Kudziwa Fresnel mapindidwe akuwala kotheka kwa una wa mawonekedwe aliyense ndi zambiri popanda izo. Komabe, kuchokera amazionera a kuthekera ndi bwino thanzi mu mawonekedwe zozungulira dzenje. Pankhaniyi, gwero kuwala ndi mfundo kuonerera ayenera kukhala pa mzere kuti ndi perpendicular kwa nsalu yotchinga ndege ndipo umadutsa pakatikati pa una. Ndipotu, mu Fresnel zone akhoza kuswa pamwamba iliyonse imene mafunde kuwala. Mwachitsanzo, equiphase pamwamba. Komabe, mu nkhani iyi zidzakhala yabwino kuswa lathyathyathya zone dzenje. Pakuti ichi tikambirana za chiyambidwe mavuto kuwala, zomwe zingathandize kudziwa osati utali wozungulira m'dera woyamba Fresnel, komanso kutsatira-ndi manambala mwachisawawa.

Ntchito kudziwa kukula kwa mphete

Kuyamba kuganiza kuti padziko dzenje mosabisa ndi pakati gwero kuwala (mfundo C) ndipo akuona (mfundo H). Ndi perpendicular kwa mzere CH. CH gawo umadutsa kuzungulira dzenje pakati (mfundo O). Popeza kuti cholinga chathu ndi olamulira chosokonekera, ndi Fresnel zone adzakhala mawonekedwe a mphete. Chigamulo adzakhala kusanduka mtima wa utali wozungulira a magulu awa ndi chiwerengero umasinthasintha (m). Mtengo pazipita amatchedwa utali wozungulira woyendera nthambi. Pofuna kuthana ndi vuto m'pofunika kuchita zomangamanga zina, akuti: kusankha mfundo zongopeka (A) mu ndege ya kutsegula ndi kulumikiza izo zigawo molunjika mzere pa mfundo chidwi ndi gwero kuwala. Chifukwa ndi makona San. Ndiye inu akhoza kupanga izo kuti yoweyula kuwala kufika kwa akuona tikuyenda pa njira ya San, kudali wautali njira kuposa amene adzatenga njira CH. Izi zikutanthauza kuti njira kusiyana CA + AN-CH imalongosola kusiyana pakati pa magawo yoweyula ali wadutsa kuchokera owonjezera (A ndi D) pa mfundo zakuthambo. Kuchokera phindu izi zimatengera mafunde chotsatira kusokonezedwa ndi malo a amatsata, ndipo motero mwamphamvu kuwala pamalo amenewo.

Mawerengedwe a utali wozungulira loyamba

Ife tikupeza kuti ngati kusiyana njira ndi wofanana ndi theka la timaganiza kuwala (λ / 2), kuwala kubwera kwa amatsata mu antiphase. Ndizachidziwikire kuti ngati kusiyana njira adzakhala zosakwana λ / 2, kuwala adzabwera mu gawo lomwelo. chikhalidwe ichi CA + AN-SN≤ λ / 2, ndi tanthauzo, ndi chikhalidwe chimene mfundo A lili mphete choyamba, i.e. ndi woyamba Fresnel nthambi. Pankhaniyi, kumalire a kusiyana bwalo njira chofanana ndi timaganiza theka la kuwala. Choncho aone kuti pali ichi kudziwa utali wozungulira zone woyamba, amaimira P _1. Pamene kusiyana njira lolingana λ / 2, zidzakhala wofanana ndi gawo o. Zikatero, ngati kutalika olumpha zayamba NKHA dzenje awiri (amangoona ankaona zoterezi embodiments), ndi tiganizira za zojambula utali wozungulira zone woyamba ndi chimafotokozera chilinganizo zotsatirazi: P ₁ = √ (λ * NKHA + o) / (NKHA + o).

Mawerengedwe a utali wozungulira Fresnel zone

Chilinganizo cha kudziŵa mfundo za radii mphete wotsatira zofanana zafotokozedwa pamwambapa, okha anawonjezera kuti numerator wa nambala anakhumba nthambi. Zikatero Kuyanjana pakathi pa kusiyana njira amakhala: CA + AN-SN≤ mamita * λ / 2 kapena CA + AH-NKHA-ON≤ mamita * λ / 2. Ndizoonekeratu kuti utali wozungulira m'dera anakhumba ndi nambala "mamita" amasonyeza chilinganizo zotsatirazi: P _mamita = √ (m * λ * NKHA + o) / (NKHA + o) = ₁ P √m

Polongosola mwachidule zotsatira zokhwima

Mwina anati kwa zone kumatula - kulekana kwa yachiwiri kuwala gwero kuti amapereka mphamvu ndi dera limodzi, monga _mamita N = π * R ² _m - π * R ² _m-1 = π * ₁ P ² = P _1. Kuwala kwa oyandikana mabacteria Fresnel amabwera mu gawo anyamata, chifukwa njira kusiyana mphete oyandikana ndi tanthauzo kukhala wofanana ndi timaganiza theka la kuwala. Generalizing chotsatirachi, tinganene kuti kumatula mabowo pa mabwalo (ngati kuwala kwa oyandikana umalandira amatsata ndi gawo kusiyana amodzi) zingatanthauze kuswa mphete pa malo omwewo. mfundo imeneyi mosavuta anasonyeza thandizo la vutoli.

Fresnel zone kwa yoweyula ndege

Taganizirani kusokonezeka kutsegula malo mu mphete n'kakang'ono a m'dera ofanana. mabwalo Awa sekondale kuwala kochokera. The matalikidwe a kuwala yoweyula kufika kwa aliyense mphete ku amatsata ndi pafupifupi chimodzimodzi. Komanso, gawo kusiyana osiyanasiyana pafupi pa mfundo H ndi chimodzimodzi. Mu nkhani iyi, amplitudes zovuta pa amatsata pamene anawonjezera mmodzi zovuta ndege mbali ya bwalo - Arc. Matalikidwe okwana yemweyo - poyambira. Tsopano tiyeni tione mmene chitsanzo kusintha kwa chimangirizo za matalikidwe vuto la kusintha kwa utali wozungulira mdzenje pokhalabe magawo ena vuto. Zikatero, ngati una akutsegula zone imodzi yokha amatsata, ndi chitsanzo kuwonjezera gawo amaperekedwa circumferentially. The matalikidwe a mphete wotsiriza zimayenda ndi makona π wachibale chigawo chapakati, mwachitsanzo. K. Njira kusiyana kwa zone woyamba, ndi tanthauzo, wofanana λ / 2. njingayo ili lidzakhala π zikutanthauza matalikidwe adzakhala theka circumference. Pankhaniyi, Uwerenge mfundo izi pa mfundo kuonerera ndi ziro - ziro poyambira kutalika. Ngati mphete atatu adzatsegulidwa, ndiye chithunzi akuimira bwalo theka ndi zina zotero. Matalikidwe mu mfundo akuona la chiwerengero mphete ndi ziro. Ngati ntchito wosamvetseka angapo mabwalo, zidzakhala wofanana ndi mtengo pazipita ndi kutalika kwa m'mimba mwake mu ndege zovuta za amplitudes Kuwonjezera. Zolinga pamwamba ali ndi lotseguka njira Fresnel mabacteria.

Mwachidule za zina zapadera

Taonani zinthu kawirikawiri. Nthawi zina, kuthetsa limati vuto kuti ntchito fractional chiwerengero cha Fresnel mabacteria. Pankhaniyi, pansi pa theka mphete kuzindikira kotala bwalo chitsanzo, lomwe zizigwirizana ndi malo theka la zone woyamba. Mofananamo masamu ina mtengo fractional. Nthawi zina chikhalidwe kukusonyeza kuti ena fractional chiwerengero mphete anatseka ndipo kwambiri lotseguka. Zikatero, matalikidwe onse a vekitala wakumunda napeza monga kusiyana kwa amplitudes wa ntchito ziwiri. Pamene mabacteria onse atsegulidwa, ndiye palibe chokhumudwitsa pa njira ya mafunde kuwala chithunzi lidzaonekera mwauzimu ndi. Likukhalira, chifukwa pamene mumatsegula ambiri mphete ayenera kuganizira kudalira la umuna wa gwero kuwala mpaka amatsata ndi malangizo a gwero sekondale. Ife tikupeza kuti kuwala m'dera ndi chiwerengero apamwamba ali matalikidwe yaing'ono. Center analandira helix ndi mu circumference pakati pa mphete yoyamba ndi yachiwiri. Choncho, munda matalikidwe zinalili pamene onse m'dera kuonekera ndi osachepera kawiri kuposa poyera litayamba woyamba, ndi mphamvu losiyana ndi kanayi.

Fresnel mapindidwe akuwala kuwala

Tiyeni tione tanthauzo la mawu amenewa. Otchedwa Fresnel mapindidwe akuwala chikhalidwe, pamene kudzera pabowo amatsegula mbali zingapo. Ngati ife adzatsegula kwambiri mphete, ndiye njirayi akhoza ananyalanyaza, amene anagwira ntchito mu chiyerekezo kuti Optics geometrical. Ngati kumene dzenje kudzera lidzatsegulidwa chifukwa akuona zayamba zone n'komwe, chikhalidwe ichi amatchedwa Fraunhofer mapindidwe akuwala. Iye ankaona kukhuta ngati gwero kuwala ndi mfundo amatsata ali pa mtunda okwanira kuchokera mdzenje.

Kuyerekezera zone mbale mandala ndi

Ngati inu mukutseka onse wosamvetseka kapena onse zone ngakhale Fresnel, pamene pa amatsata ndi kuwala yoweyula ndi matalikidwe wamkulu. Aliyense mphete ya ndege zovuta amapereka bwalo theka. Choncho ngati zosatseka ndi mabacteria wosamvetseka, ndiye okwana kokha mwauzimu amachepetsa la mabwalo, amene amathandiza kuti matalikidwe yaikulu ya "pansi-mmwamba". Chopunthwitsa mu njira ya yoweyula kuwala, amene mtundu umodzi wokha wa mphete lotseguka, wotchedwa zone mbale. Mphamvu ya kuwala amatsata mobwerezabwereza upambana mphamvu ya kuwala bwalolo. Ichi ndi chifukwa chakuti yoweyula kuwala kwa wina ndi mphete lotseguka ndi flagged kuti amatsata mu gawo lomwelo.

N'chimodzimodzi anaona ndi moganizira kuwala ndi mandala a. Iwo, mosiyana ndi mbale, palibe mphete si anatsekedwa ndipo limayenda kuwala mu gawo ndi π * (+ 2 π * m) ku mabwalo omwe anatseka zone mbale. Chifukwa, matalikidwe a yoweyula kuwala kawiri. Komanso, mandala kumatha otchedwa reciprocal gawo mosinthana omwe ali mkati mphete limodzi. Ndi zambiri pa ndege zovuta za circumference theka lililonse zone mu molunjika mzere gawo. Chifukwa, matalikidwe ukuwonjezeka ndi nthawi π, ndipo lonse zovuta mandala ndege mwauzimu zikuchitika mu mzere wolunjika.