Kungani Fresnel zone

zone Fresnel - iindawo apho komhlaba okanye isandi ukukhanya amaza ukwenza izibalo iziphumo diffraction isandi okanye ukukhanya. Le nqubo kuqala ngo-1815 O.Frenel.

ulwazi zembali

Augustin-Zhan Frenel (10.06.1788-14.07.1827) - yamachiza French. Wayitshabalalisa ubomi bakhe ukufunda ngeempawu yokukhanya ebonakalayo. Kwakhona ngo-1811 phantsi kwempembelelo E. Malus waqalisa ngokuzimeleyo ukufunda physics, kungekudala waba nomdla kuphando zovavanyo kwinkalo ngokukhanya. Ngowe-1814, i "bafumana" umgaqo uphazamiso, kwaye ngo-1816 wongeza umgaqo ezaziwayo-kakuhle ezingenamandla ze Huygens, owazise ingqiqo setekisi ukungenela amaza nezakhiwo. Ngo-1818, sakhela phezu umsebenzi wenziwe, waba ingcamango yokuba diffraction ukukhanya. Watshayelela umkhuba ingqalelo diffraction kusukwa, kwakunye emngxunyeni setyhula. amalinge Kwenziwa, ngoku ziyahlonelwa, kunye biprism kunye bizerkalami sokuphamazisa ukukhanya. Ngowe-1821 waba isibakala yohlobo ezinqamlezayo kwamaza ukukhanya, ngowe-1823 wavula nokwehlukana setyhula kunye okweqanda. Wachaza ngokusekelwe lwamaza izimvo nokwehlukana chromatic, kwakunye njengokujikeleza moya ka nokwehlukana yokukhanya kunye birefringence. Ngowe-1823, Walizinzisa imithetho refraction kunye ibonisa ukukhanya kwindawo esisigxina tyaba phakathi eendaba ezimbini. Kunye Jung ingqalelo ngumdali ngokukhanya otshangatshangiswayo. Ngaba Umsunguli izixhobo uphazamiseko ezininzi, ezifana njengesipili okanye Fresnel biprism Fresnel. Liyiqwalasele ngunozala indlela ngokwesiseko entsha lighthouse ukhanyiso.

A bit mbono

Ukumisela Fresnel diffraction kunokwenzeka ukuba emfanteni nayiphi imilo kunye ngokubanzi ngaphandle kwayo. Noko ke, ukususela kwinqanaba umbono ngokokusebenza kungcono ukuluphatha enembonakalo umngxuma setyhula. Kulo mzekelo, umthombo wokukhanya nencopho mkhanya kufuneka kumgca ukuba aa-moya screen kwaye udlula embindini emngxunyeni. Enyanisweni, kummandla Fresnel lwaphula nasiphi umphandle apho amaza okukhanya. Umzekelo, umphezulu equiphase. Noko ke, kule meko kuya kuba lula ukuba ndimaphule izowuni umngxuma flat. Kuba oku ingqalelo iingxaki eziziziqalelo woqondo, nto leyo eya kusenza sikwazi ukubona embindini kommandla Fresnel yokuqala nje kuphela, kodwa ulandele-up ngamanani random.

Umsebenzi yokumisela ubungakanani clock

Ukuqala ukucinga ukuba kumphezulu umngxuma caba phakathi umthombo wokukhanya (point C) kunye mkhanyo (point H). Kuyinto nkqo ukuya kumgca CH. CH ingxenye udlula kwiziko umngxuma ngeenxa (point O). Ekubeni injongo yethu esqwini wolingano, i Fresnel kwindawo ziya kuba ngokohlobo amakhonkco. Isigqibo aya kuncitshiswa abe ngokumiselwa umgama ezi izangqa ezinenani engenasizathu (m). Elona xabiso liphezulu ubizwa ngokuba kwirediyasi bommandla. Ukusombulula le ngxaki oko kuyimfuneko ukwenza zokwakha ezongezelelweyo, ezizezi: khetha inqaku engenasizathu (A) xa moya bomnyango kwaye ixhume ziqwempu umgca othe ngqo ukusuka kwindawo lokuqaphela kunye nomthombo ukukhanya. Isiphumo unxantathu SAN. Ngoko ungenza ukuze iliza ukukhanya ezifikayo mkhanyo endleleni le SAN, uwele umendo elide ngaphezu uya kuthabatha CH endleleni. Oku kuthetha ukuba i CA umahluko umendo + AN-CH ichaza umahluko phakathi izigaba yomtshangatshangiso zidluliselwa ukusuka kwimithombo eziziisekondari (A no-D) abakwindawo mkhanya. Ukusuka eli xabiso kuxhomekeke amaza ukuphazamisana iziphumo kunye imeko obukeleyo, yaye ngenxa yoko ke ukukhanya ngelo xesha.

Ukubalwa embindini yokuqala

Sifumanisa ukuba, ukuba umahluko umendo uyalingana isiqingatha kwamaza ukukhanya (λ / 2), esiza ukukhanya okhangeleka kumbukeli in antiphase. Oku kunokwenziwa isigqibo sokuba ukuba umahluko umendo uya kuba ngaphantsi kwe λ / 2, ukukhanya kuza kwisigaba esinye. Le CA imeko + AN-SN≤ λ / 2, ngokwenkcazelo, bakwiyiphi imeko ukuba ngongoma A ise khonkcweni, ngamanye amazwi oko ummandla Fresnel yokuqala. Kulo mzekelo, kumda umahluko wesangqa umendo uyalingana isiqingatha yokukhanya. Ngenxa yoko lo lenxaki ukufumanisa embindini kommandla yokuqala, P _{1 zibonakaliswe.} Xa umahluko indlela ehambelana λ / 2, kuya kuba kulingana ingxenye OA. Xa kunjalo, ukuba imigama ngaphezulu mngxuma ubukhulu kakhulu CO (njenge ingqalelo nje embodiments ezinjalo), i kwingqalelo radius zejometri lommandla yokuqala sichazwa ngokuthi le fomyula ilandelayo: P ₁ = √ (λ * CO + OH) / (CO + OH).

Ukubalwa kwirediyasi Fresnel zone

Indlela yokuqingqa amaxabiso radii umsebenzi osontiweyo ezilandelayo ziyafana kuxoxwe ngasentla, wongezelela kuphela kwinani inani zone oyifunayo. Ngaloo ukulingana Kwimeko umahluko indlela uba: CA + AN-SN≤ m * λ / 2 okanye CA + AH-CO-ON≤ m * λ / 2. Oku kulandela ukuba owela ngaphakathi kwama-ndawo efunekayo kunye nenani "m" sichaza le fomyula ilandelayo: P _m = √ (m * λ * CO + OH) / (CO + OH) = ₁ P √m

Ebeka iziphumo eziphakathi

Kusenokwenzeka ukuba kuqatshelwe ukuba ngenxa izowuni ukuqhekezwa - ukwahlulwa umthombo wokukhanya lesibini ukuya izinto ngamandla ngokuba kwindawo enye, njengoko _m n = π * ^R-2 _m - π * R ² _m-1 = π * ₁ P ² = P _1. Ukukhanya ezindaweni Fresnel elingummelwane kuza kwisigaba esahlukileyo, kuba umahluko endleleni amakhonkco asebumelwaneni ngokwenkcazo ukulingana isiqingatha yokukhanya. Generalizing le yoko, sigqiba ukuba qhiphu mingxuma kwi njengezangqa (kangangokuba ukukhanya asebumelwaneni ifikelela mkhanyo kunye umahluko isigaba fixed) kuthetha waphula ijikazi kwi ndawo enye. Le yinto lulula onokuyibonisa ngoncedo le ngxaki.

ummandla Fresnel ibe ngumtshangatshangiso moya

Cinga ukwaphuka lokuvula indawo ibe amakhonkco sokurhuqa kwindawo ngokulinganayo. Ezi izangqa imithombo ukukhanya eziziisekondari. Le awo zokufika yomtshangatshangiso ukukhanya umsesane okhangeleka kumbukeli, malunga enye. Ukongeza, umahluko isigaba ukusuka kuluhlu ezikufutshane kwindawo H nayo enye. Kulo mzekelo, i ngezantya ixandile mkhanyo xa zafakwa nganye entsonkothileyo uhlobo moya yinxalenye isangqa - arc. Le awo iyonke efanayo - kuvuka. Ngoku cinga ngendlela indlela ekutshintsheni summation of awo kwimeko sokutshintshwa kwirediyasi emngxunyeni lo gama kugcinwe ezinye i parameters le ngxaki. Xa kunjalo, ukuba emngxunyeni ivula ummandla omnye kuphela mkhanyo, inxenye ukudibanisa ipateni inikwa circumferentially. Le awo le ring lokugqibela esijikeleziswa nge-engile π kuthelekiswa umbindi, okt. K. Umahluko Umendo kwindawo yokuqala, ngokwenkcazelo, lingana λ / 2. Le angela uya π kuthetha awo aya kuba isiqingatha achazwe apha. Kulo mzekelo, isixa ezi amaxabiso kwindawo mazwi zero - zero ubude usinga. Ukuba amakhonkco ezintathu iya kuvulwa, ngoko ke umfanekiso uya kumela isangqa isiqingatha njalo njalo. Le awo kwi ukuba ngenxa point of an noba inani amakhonkco ngu zero. Kwaye kwimeko xa usebenzisa inani umtya izangqa, kuya kuba elingana nexabiso elikhulu kwaye ubude ubukhulu kwi-moya entsonkothileyo zokudibanisa ngezantya. Iinjongo angentla ngokupheleleyo indlela open source lwe mimandla Fresnel.

Ngokufutshane malunga ezithile

Cinga iimeko ezinqabileyo. Ngamanye amaxesha, ukusombulula ithi ingxaki ezisebenzisa inani iqhezu mimandla Fresnel. Kulo mzekelo, ngaphantsi kwesiqingatha umsesane bayile ipateni ikota isangqa, nto leyo eya elungelelene isiqingatha kummandla yokuqala. Ngokufanayo kubalwa naliphi na inani iqhezu. Ngamanye amaxesha imeko lucebisa ukuba inani elithile iqhezu amakhonkco yavalwa njalo evulekile kakhulu. Kwimeko enjalo ke, awo elipheleleyo kumda wesangqa intsimi sabufumana umahluko ngezantya yemisebenzi ezimbini. Xa yonke imimandla zivulekile, ngoko akukho yimiqobo endleleni amaza okukhanya, umfanekiso uya kukhangela njenge uwele. Kubonakala, kuba xa uvula inani elikhulu amakhonkco kufuneka athathe ingqalelo ukuxhomekeka yokuba ukuphuma umthombo wokukhanya okhangeleka kumbukeli point kunye ulwalathiso umthombo eziziisekondari. Sifumanisa ukuba ukukhanya kummandla kunye nenani eliphakamileyo a awo encinane. Centre kweleli endibufumeneyo kwi achazwe apha embindini emakhonkcweni yokuqala neyesibini. Ngoko ke, lo awo entsimini kwimeko apho yonke indawo ebonakalayo lingaphantsi kwe kabini kunaleyo kwindawo evulekileyo omnye idiski yokuqala, yaye amandla yahlukile ngokuphindwe kane.

Fresnel ukukhanya diffraction

Makhe sijonge oko kuthethwa kule kota. Ebizwa Fresnel diffraction imeko, xa kumngxuma ivula kwiindawo ezininzi. Ukuba siza kuvula ezininzi namakhonkco, ngoko olu khetho nazo zingananzwa, oko kukuthi wazibhokoxa kwi kelelo ukuya yokukhanya kwijometri. Kwimeko apho imbobo ivulwe ukuze mkhanyo kakhulu zone ngaphantsi kwe omnye, le meko kuthiwa Fraunhofer diffraction. Yena ithathwa anelisekile ukuba umthombo wokukhanya kunye ingongoma mkhanyo ke mgama esilingeneyo mngxuma.

Ukuthelekisa lens nembasa zone kunye

Ukuba uvala zonke odd okanye wonke ummandla nokuba Fresnel, ngexa kwi-mkhanyo yi iliza ukukhanya kunye namandla awo enkulu. ring ngalinye moya oluntsonkothileyo unika isangqa isiqingatha. Ngoko ke, ukuba ahlale evuliwe ezikwiizowuni odd, ngoko ke lilonke iza kungajikeleza kuphela kubini ze izangqa, leyo igalelo awo lulonke "bottom-up". Le umqobo endleleni lencinibakazi ukukhanya, apho omnye uhlobo kuphela amakhonkco ezivulekileyo, ngokuba imbasa zone. Ubunzulu yokukhanya kwi-mkhanyo ngokuphindaphindiweyo igqithe ubunzulu ukukhanya nembasa. Oku kungenxa yokuba yomtshangatshangiso ukukhanya ring nganye evulekileyo enendwe okhangeleka kumbukeli kwisigaba efanayo.

Imeko efanayo yabonakala ngokujolisa ukukhanya kunye lens. Ngoko, ngokungafaniyo iipleyiti, akukho amakhonkco nje ivaliwe, kwaye ihambisa ukukhanya kwisigaba ngu π * (+ 2 π * m) ukusuka izangqa eyavalwa ipleyiti zone. Ngenxa yoko, xa kabini awo lencinibakazi ukukhanya. Ngaphezu koko, ilens akubikho-ekuthiwa iishifti yesigaba kusiyiwa emva leyo kwisithuba isangqa enye. Ayanda-moya entsonkothileyo osisiqingatha achazwe apha ommandla ngamnye icandelo umgca othe ngqo. Ngenxa yoko, ukunyuka kwawo namandla awo ngokuphindwe π, kwaye ilens yonke moya siba esimbaxa zenzeka zibe umgca othe ngqo.