Asalin ka'ida na Optical modulator

Modulator na gani, An yi amfani da shi don sarrafa ƙarfin haske, rarrabuwa na electro-optic, thermooptic, acoustooptic, duk na gani, ainihin ka'idar tasirin electro-optic.
Modulator na gani yana ɗaya daga cikin muhimman na'urorin haɗaɗɗiyar gani a cikin sadarwa mai sauri da gajeriyar hanya. Light modulator bisa ga tsarin daidaitawa, za a iya raba zuwa electro-optic, thermooptic, acoustooptic, duk Tantancewar, da dai sauransu, sun dogara ne a kan asali ka'idar ne iri-iri daban-daban siffofin electro-optic sakamako, acoustooptic sakamako, magnetoptic sakamako. , Franz-Keldysh sakamako, jimla da kyau Stark sakamako, m watsawa sakamako.

Theelectro-Optical modulatorna'ura ce da ke daidaita ma'anar refractive, absorptivity, amplitude ko lokacin hasken fitarwa ta hanyar canjin wutar lantarki ko filin lantarki. Ya fi sauran nau'ikan na'urori masu daidaitawa ta fuskar asara, amfani da wutar lantarki, saurin gudu da haɗin kai, sannan kuma shine mafi yawan amfani da na'urar a halin yanzu. A cikin tsarin watsawar gani, watsawa da liyafar, ana amfani da na'urar modulator don sarrafa ƙarfin haske, kuma rawar da take takawa tana da mahimmanci.

Manufar gyare-gyaren haske shine canza siginar da ake so ko bayanan da aka watsa, ciki har da "kawar da siginar baya, kawar da hayaniya, da tsangwama", don sauƙaƙe sarrafawa, watsawa da ganowa.

Ana iya raba nau'ikan daidaitawa zuwa manyan nau'i biyu dangane da inda aka ɗora bayanin akan igiyar haske:

Ɗayan ita ce ƙarfin tuƙi na tushen hasken da siginar lantarki ke daidaita shi; Sauran shine don daidaita watsa shirye-shiryen kai tsaye.

Na farko ana amfani da shi ne don sadarwa ta gani, kuma na karshen ana amfani da shi ne don sanin gani. A takaice: na'ura na ciki da na'ura na waje.

Dangane da hanyar daidaitawa, nau'in daidaitawa shine:

1) Matsala mai ƙarfi;

2) Tsarin tsari;

3) Motsa jiki na polarization;

4) Mitar mita da tsayin raƙuman ruwa.

1.1, ƙarfin daidaitawa

Motsawar ƙarfin haske shine ƙarfin haske azaman abin daidaitawa, amfani da abubuwan waje don auna DC ko jinkirin canjin siginar hasken zuwa saurin saurin saurin siginar hasken, ta yadda za'a iya amfani da amplifier zaɓi na mitar AC ƙara, sa'an nan kuma adadin da za a auna fitar da ci gaba.

1.2, daidaita yanayin lokaci

Ka'idar yin amfani da abubuwan waje don canza yanayin raƙuman haske da aunawa jiki ta hanyar gano canje-canjen lokaci ana kiransa canjin lokaci na gani.

Matsayin hasken wutar lantarki yana ƙayyade ta tsawon jiki na yaduwar haske, ma'anar refractive na matsakaicin watsawa da rarrabawa, wato, ana iya haifar da canjin lokaci na hasken hasken ta hanyar canza sigogi na sama. don cimma daidaituwar lokaci.

Saboda mai gano haske gabaɗaya ba zai iya fahimtar canjin lokaci na igiyar hasken ba, dole ne mu yi amfani da fasahar tsangwama na haske don canza canjin lokaci zuwa canjin ƙarfin haske, don cimma nasarar gano adadi na zahiri na waje, saboda haka. , Tsarin lokaci na gani ya kamata ya haɗa da sassa biyu: ɗaya shine tsarin jiki na samar da canjin lokaci na igiyar haske; Na biyu shi ne tsoma bakin haske.

1.3. Modulation na polarization

Hanya mafi sauƙi don cimma daidaituwar haske shine juya polarizers biyu dangane da juna. Dangane da ka'idar Malus, ƙarfin fitowar hasken shine I=I0cos2α

Inda: I0 yana wakiltar ƙarfin hasken da aka yi ta hanyar polarizers biyu lokacin da babban jirgin sama ya daidaita; Alpha yana wakiltar kusurwa tsakanin manyan jirage biyu na polarizers.

1.4 Mitar mitar da tsayin raƙuman ruwa

Ka'idar yin amfani da abubuwan waje don canza mita ko tsayin haske da auna ma'auni na zahiri na waje ta hanyar gano canje-canje a cikin mita ko tsayin haske ana kiransa mita da haɓakar haske.