Fa'idodi da mahimmancin lithium niobate mai siririn fim a cikin fasahar photon mai haɗaka ta microwave
Fasahar yin amfani da microwave photonyana da fa'idodin babban bandwidth na aiki, ƙarfin sarrafawa mai ƙarfi da ƙarancin asarar watsawa, wanda ke da yuwuwar karya gibin fasaha na tsarin microwave na gargajiya da inganta aikin kayan aikin bayanai na lantarki na soja kamar radar, yaƙin lantarki, sadarwa da aunawa da sarrafawa. Duk da haka, tsarin photon na microwave wanda aka gina akan na'urori daban-daban yana da wasu matsaloli kamar babban girma, nauyi mai nauyi da rashin kwanciyar hankali, wanda ke takaita amfani da fasahar photon na microwave a cikin dandamalin sararin samaniya da na iska. Saboda haka, fasahar photon na microwave da aka haɗa tana zama muhimmiyar tallafi don karya aikace-aikacen photon na microwave a cikin tsarin bayanai na lantarki na soja da kuma ba da cikakken wasa ga fa'idodin fasahar photon na microwave.
A halin yanzu, fasahar haɗakar photonic ta tushen SI da fasahar haɗakar photonic ta tushen INP sun ƙara girma bayan shekaru da yawa na ci gaba a fannin sadarwa ta gani, kuma an saka kayayyaki da yawa a kasuwa. Duk da haka, don amfani da microwave photon, akwai wasu matsaloli a cikin waɗannan nau'ikan fasahar haɗakar photon guda biyu: misali, haɗin lantarki mara layi na Si modulator da InP modulator ya saba wa babban layi da manyan halaye masu ƙarfi da fasahar microwave photon ke bi; Misali, maɓallin silicon na gani wanda ke gano canjin hanyar gani, ko bisa ga tasirin zafi-na gani, tasirin piezoelectric, ko tasirin watsawa na allurar ɗaukar kaya, yana da matsalolin saurin sauyawa a hankali, amfani da wutar lantarki da amfani da zafi, wanda ba zai iya biyan buƙatun binciken haske mai sauri da aikace-aikacen microwave photon masu girma ba.
Lithium niobate koyaushe shine zaɓi na farko don babban gududaidaitawar lantarkikayan aiki saboda kyakkyawan tasirinsa na lantarki mai layi. Duk da haka, lithium niobate na gargajiyana'urar sarrafa haske ta lantarki (electro-optical modulator)An yi shi ne da babban kayan lu'ulu'u na lithium niobate, kuma girman na'urar yana da girma sosai, wanda ba zai iya biyan buƙatun fasahar photon na microwave da aka haɗa ba. Yadda ake haɗa kayan lithium niobate tare da layin electro-optical coefficient cikin tsarin fasahar photon na microwave da aka haɗa ya zama burin masu bincike masu dacewa. A cikin 2018, wata ƙungiyar bincike daga Jami'ar Harvard da ke Amurka ta fara ba da rahoton fasahar haɗa photonic bisa ga siririn fim na lithium niobate a cikin Yanayi, saboda fasahar tana da fa'idodin haɗakarwa mai yawa, babban bandwidth na daidaitawa na electro-optical, da kuma babban layi na tasirin electro-optical, da zarar an ƙaddamar da shi, nan da nan ya jawo hankalin ilimi da masana'antu a fannin haɗa photonic da microwave photonics. Daga mahangar aikace-aikacen microwave photon, wannan takarda tana duba tasirin da mahimmancin fasahar haɗa photon bisa ga siririn fim na lithium niobate akan haɓaka fasahar photon na microwave.
Kayan fim na lithium niobate mai sirara da fim na bakin cikina'urar daidaita lithium niobate
A cikin shekaru biyu da suka gabata, wani sabon nau'in kayan lithium niobate ya fito, wato, an cire fim ɗin lithium niobate daga babban lu'ulu'u na lithium niobate ta hanyar "yanka ion" kuma an haɗa shi da Si wafer tare da layin silica don samar da kayan LNOI (LiNbO3-On-Insulator) [5], wanda ake kira kayan lithium niobate na bakin ciki a cikin wannan takarda. Ana iya zana jagororin raƙuman ruwa masu tsayi sama da nanometer 100 akan kayan lithium niobate na bakin ciki ta hanyar ingantaccen tsarin etching, kuma ingantaccen bambancin refractive na jagororin raƙuman ruwa da aka samar zai iya kaiwa sama da 0.8 (fiye da bambancin refractive na jagororin raƙuman ruwa na lithium niobate na gargajiya na 0.02), kamar yadda aka nuna a Hoto na 1. Jagorar raƙuman ruwa mai ƙarfi yana sauƙaƙa daidaita filin haske tare da filin microwave lokacin tsara mai daidaitawa. Don haka, yana da amfani a sami ƙarancin ƙarfin lantarki na rabin-wave da babban bandwidth na daidaitawa a cikin ɗan gajeren tsayi.
Bayyanar jagorar wavelength na lithium niobate mai ƙarancin asara yana karya gibin ƙarfin lantarki mai ƙarfi na na'urar lantarki ta lithium niobate ta gargajiya. Tazarar lantarki za a iya rage ta zuwa ~ 5 μm, kuma haɗuwar da ke tsakanin filin lantarki da filin yanayin gani yana ƙaruwa sosai, kuma vπ · L yana raguwa daga fiye da 20 V·cm zuwa ƙasa da 2.8 V·cm. Saboda haka, a ƙarƙashin irin wannan ƙarfin lantarki na rabin-wave, tsawon na'urar za a iya rage shi sosai idan aka kwatanta da na'urar lantarki ta gargajiya. A lokaci guda, bayan inganta sigogin faɗin, kauri da tazara na na'urar lantarki mai tafiya, kamar yadda aka nuna a cikin hoton, na'urar lantarki za ta iya samun damar bandwidth mai girma na modulation fiye da 100 GHz.
Hoto na 1 (a) rarraba yanayin da aka ƙididdige da kuma （b) hoton giciye na jagorar raƙuman ruwa na LN
Hoto na 2 (a) Tsarin jagorar raƙuman ruwa da lantarki da kuma （b) coreplate na LN modulator
Kwatanta masu gyaran lithium niobate na bakin ciki da masu gyaran lithium niobate na gargajiya, masu gyaran silicon da masu gyaran indium phosphide (InP) da sauran masu gyaran electro-optical masu saurin gaske, manyan sigogin kwatancen sun haɗa da:
(1) Samfurin tsawon volt-rabi (vπ ·L, V·cm), yana auna ingancin daidaitawar modulator, ƙaramar ƙimar, mafi girman ingancin daidaitawa;
(2) 3 dB modulation bandwidth (GHz), wanda ke auna martanin modulator ga high-mita modulation;
(3) Asarar shigar da haske (dB) a yankin daidaitawa. Ana iya gani daga tebur cewa siraran fim na lithium niobate modulator yana da fa'idodi bayyanannu a cikin bandwidth na daidaitawa, ƙarfin lantarki na rabin-wave, asarar haɗin kai na gani da sauransu.
An haɓaka silicon, a matsayin ginshiƙin haɗakar optoelectronics, zuwa yanzu, tsarin ya balaga, ƙaramin aikinsa yana da amfani ga haɗakar na'urori masu aiki/marasa aiki, kuma an yi nazari sosai kan modulator ɗinsa a fannin sadarwa ta gani. Tsarin daidaitawar lantarki-optical na silicon galibi shine rage yawan jigilar kaya, allurar jigilar kaya da tarin jigilar kaya. Daga cikinsu, bandwidth na modulator ya fi kyau tare da tsarin rage yawan jigilar kaya na digiri na layi, amma saboda rarraba filin gani yana haɗuwa da rashin daidaituwa na yankin ragewa, wannan tasirin zai gabatar da karkacewar tsari na biyu mara layi da sharuɗɗan karkacewar tsari na uku, tare da tasirin sha na mai ɗaukar kaya akan haske, wanda zai haifar da raguwar girman daidaitawar gani da karkacewar sigina.
Mai daidaita InP yana da tasirin electro-optical mai ban mamaki, kuma tsarin rijiyar quantum mai matakai da yawa zai iya samar da masu daidaita ƙarfin lantarki mai yawa da ƙarancin tuƙi tare da Vπ·L har zuwa 0.156V · mm. Duk da haka, bambancin ma'aunin refractive tare da filin lantarki ya haɗa da sharuɗɗan layi da marasa layi, kuma ƙaruwar ƙarfin filin lantarki zai sa tasirin tsari na biyu ya bayyana. Saboda haka, masu daidaita silicon da InP electro-optical suna buƙatar amfani da son zuciya don samar da haɗin pn lokacin da suke aiki, kuma haɗin pn zai kawo asarar sha zuwa haske. Duk da haka, girman mai daidaita waɗannan biyun ƙarami ne, girman mai daidaita InP na kasuwanci shine 1/4 na mai daidaita LN. Ingantaccen daidaitawa, ya dace da manyan hanyoyin sadarwa na watsawa na dijital na gani mai yawa da gajere kamar cibiyoyin bayanai. Tasirin electro-optical na lithium niobate ba shi da tsarin ɗaukar haske da ƙarancin asara, wanda ya dace da dogon nesa mai haɗin kai.sadarwa ta ganitare da babban ƙarfin aiki da kuma babban ƙarfin aiki. A cikin aikace-aikacen photon na microwave, ma'aunin electro-optical na Si da InP ba su da layi, wanda bai dace da tsarin photon na microwave ba wanda ke bin babban layi da babban motsi. Kayan lithium niobate ya dace sosai don aikace-aikacen photon na microwave saboda cikakken layin daidaitawar electro-optical.
Lokacin Saƙo: Afrilu-22-2024