Ubwino ndi kufunika kwa lithiamu niobate yopyapyala mu ukadaulo wophatikizidwa wa microwave photon
Ukadaulo wa fotoni wa mu microwaveIli ndi ubwino wa bandwidth yayikulu yogwirira ntchito, mphamvu yogwirira ntchito yofanana komanso kutayika kochepa kwa ma transmission, komwe kumatha kuswa zopinga zaukadaulo zamakina achikhalidwe a microwave ndikukweza magwiridwe antchito a zida zamagetsi zamagetsi monga radar, nkhondo zamagetsi, kulumikizana ndi kuyeza ndi kuwongolera. Komabe, makina a microwave photon otengera zida zapadera ali ndi mavuto ena monga kuchuluka kwakukulu, kulemera kwakukulu komanso kukhazikika kosakhazikika, zomwe zimaletsa kwambiri kugwiritsa ntchito ukadaulo wa microwave photon m'mapulatifomu oyenda mumlengalenga ndi m'mlengalenga. Chifukwa chake, ukadaulo wophatikizidwa wa microwave photon ukukhala chithandizo chofunikira pakuswa kugwiritsa ntchito microwave photon mumakina azidziwitso zamagetsi ankhondo ndikupereka mwayi wonse ku zabwino za ukadaulo wa microwave photon.
Pakadali pano, ukadaulo wophatikiza ma photonic wochokera ku SI ndi ukadaulo wophatikiza ma photonic wochokera ku INP wakula kwambiri pambuyo pa zaka zambiri za chitukuko m'munda wa kulumikizana kwa kuwala, ndipo zinthu zambiri zayikidwa pamsika. Komabe, pakugwiritsa ntchito ma microwave photon, pali mavuto ena m'mitundu iwiri iyi ya ukadaulo wophatikiza ma photon: mwachitsanzo, coefficient ya nonlinear electro-optical ya Si modulator ndi InP modulator ndi yosiyana ndi linearity yayikulu ndi mawonekedwe akuluakulu oyendetsedwa ndi ukadaulo wa ma microwave photon; Mwachitsanzo, switch ya silicon optical yomwe imazindikira kusintha kwa njira ya kuwala, kaya kutengera mphamvu ya kutentha, mphamvu ya piezoelectric, kapena mphamvu ya carrier injection dispersion, ili ndi mavuto a liwiro losintha pang'onopang'ono, kugwiritsa ntchito mphamvu ndi kugwiritsa ntchito kutentha, komwe sikungakwaniritse kusanthula kwachangu kwa beam ndi kugwiritsa ntchito ma microwave photon ambiri.
Lithium niobate nthawi zonse yakhala chisankho choyamba pa liwiro lalikulukusintha kwa magetsi ndi kuwalazipangizo chifukwa cha mphamvu yake yabwino kwambiri ya electro-optic. Komabe, lithiamu yachikhalidwe ndi niobatemodulator yamagetsi ndi kuwalaAmapangidwa ndi zinthu zazikulu za lithiamu niobate crystal, ndipo kukula kwa chipangizochi ndi kwakukulu kwambiri, komwe sikungakwaniritse zosowa za ukadaulo wa microwave photon. Momwe mungaphatikizire zinthu za lithiamu niobate ndi linear electro-optical coefficient mu dongosolo la ukadaulo wa microwave photon lakhala cholinga cha ofufuza oyenerera. Mu 2018, gulu lofufuza kuchokera ku Harvard University ku United States linanena koyamba za ukadaulo wophatikiza photonic wozikidwa pa lithiamu niobate yopyapyala mu Nature, chifukwa ukadaulowu uli ndi ubwino wophatikiza kwambiri, bandwidth yayikulu ya electro-optical modulation, komanso linearity yayikulu ya electro-optical effect, ikangoyambitsidwa, nthawi yomweyo idapangitsa chidwi cha ophunzira ndi mafakitale pankhani yophatikiza photonic ndi microwave photonics. Kuchokera pamalingaliro a kugwiritsa ntchito microwave photon, pepalali likuwunikanso momwe ukadaulo wophatikiza photon wozikidwa pa lithiamu niobate yopyapyala pakukula kwa ukadaulo wa microwave photon.
Filimu yopyapyala ya lithiamu niobate ndi filimu yopyapyalamodulator ya lithiamu niobate
M'zaka ziwiri zaposachedwa, mtundu watsopano wa zinthu za lithiamu niobate waonekera, ndiko kuti, filimu ya lithiamu niobate imachotsedwa kuchokera ku kristalo yayikulu ya lithiamu niobate pogwiritsa ntchito njira ya "ion slicing" ndikulumikizidwa ku wafer ya Si ndi silica buffer layer kuti ipange zinthu za LNOI (LiNbO3-On-Insulator) [5], zomwe zimatchedwa zinthu za lithiamu niobate zomwe zili mu pepalali. Ma Ridge waveguides okhala ndi kutalika kopitilira 100 nanometers amatha kujambulidwa pazinthu za lithiamu niobate za filimu yopyapyala pogwiritsa ntchito njira yowongoka yowuma, ndipo kusiyana kwa refractive index kwa ma waveguides opangidwa kumatha kufika pa 0.8 (kokwera kwambiri kuposa kusiyana kwa refractive index kwa ma waveguides achikhalidwe a lithiamu niobate a 0.02), monga momwe zasonyezedwera pa Chithunzi 1. Waveguide yochepetsedwa kwambiri imapangitsa kuti zikhale zosavuta kufananiza kuwala ndi microwave field popanga modulator. Chifukwa chake, ndikopindulitsa kupeza voltage yotsika ya theka la mafunde ndi bandwidth yayikulu yosinthira muutali waufupi.
Kuwoneka kwa mafunde a lithiamu niobate submicron otsika mtengo kumaphwanya botolo la mphamvu yoyendetsa yamagetsi yachikhalidwe ya lithiamu niobate electro-optic modulator. Malo a maelekitirodi amatha kuchepetsedwa kufika pa ~ 5 μm, ndipo kuphatikizika pakati pa mphamvu yamagetsi ndi mphamvu yamagetsi kumawonjezeka kwambiri, ndipo vπ ·L imachepa kuchoka pa 20 V·cm mpaka pansi pa 2.8 V·cm. Chifukwa chake, pansi pa mphamvu yamagetsi ya theka la mafunde omwewo, kutalika kwa chipangizocho kumatha kuchepetsedwa kwambiri poyerekeza ndi modulator yachikhalidwe. Nthawi yomweyo, mutakonza magawo a m'lifupi, makulidwe ndi nthawi ya elekitirodi yoyendayenda, monga momwe zasonyezedwera pachithunzichi, modulator imatha kukhala ndi mphamvu ya bandwidth yosinthira kwambiri kuposa 100 GHz.
Chithunzi 1 (a) chowerengera kugawa kwa mawonekedwe ndi chithunzi cha （b） cha gawo lopingasa la LN waveguide
Chithunzi 2 (a) Waveguide ndi kapangidwe ka electrode ndi （b） coreplate ya LN modulator
Kuyerekeza ma modulators a lithiamu niobate opyapyala ndi ma modulators achikhalidwe a lithiamu niobate amalonda, ma modulators opangidwa ndi silicon ndi ma indium phosphide (InP) ndi ma modulators ena omwe alipo a electro-optical modulator, magawo akuluakulu a kufananizako ndi awa:
(1) Chogulitsa cha kutalika kwa theka la mafunde (vπ · L, V · cm), poyesa mphamvu ya modulation ya modulator, mtengo wake ukakhala wochepa, mphamvu ya modulation imakwera;
(2) bandwidth ya 3 dB modulation (GHz), yomwe imayesa momwe modulator imayankhira ku modulation ya ma frequency apamwamba;
(3) Kutayika kwa Optical Insertion (dB) m'dera la modulation. Zikuoneka kuchokera patebulo kuti thin film lithium niobate modulator ili ndi ubwino woonekeratu mu modulation bandwidth, half-wave voltage, optical interpolation loss ndi zina zotero.
Silicon, monga mwala wapangodya wa optoelectronics yolumikizidwa, yapangidwa mpaka pano, njirayi yakula, kuchepera kwake kumathandiza kuti zipangizo zogwira ntchito/zosagwira ntchito zigwirizane kwambiri, ndipo modulator yake yaphunziridwa kwambiri komanso mozama pankhani yolumikizirana ndi kuwala. Njira yosinthira magetsi ya silicon makamaka ndi kuchepetsa mphamvu ya carrier, injection ya carrier ndi carrier accumulation. Pakati pawo, bandwidth ya modulator ndi yabwino kwambiri ndi linear degree carrier depletion mechanism, koma chifukwa chakuti optical field distribution imagwirizana ndi kusafanana kwa dera lotha ntchito, izi zidzayambitsa nonlinear second-order distortion ndi third-order intermodulation terms, pamodzi ndi zotsatira za absorption ya carrier pa kuwala, zomwe zingapangitse kuti optical modulation amplitude ndi signal distortion zichepe.
Module ya InP ili ndi zotsatira zabwino kwambiri za electro-optical, ndipo kapangidwe kake ka multi-layer quantum chitsime kamatha kuzindikira ma modulators amphamvu kwambiri komanso otsika kwambiri okhala ndi Vπ·L mpaka 0.156V · mm. Komabe, kusiyanasiyana kwa refractive index ndi electric field kumaphatikizapo mawu a linear ndi nonlinear, ndipo kuwonjezeka kwa mphamvu ya electric field kudzapangitsa kuti zotsatira zachiwiri ziwonekere. Chifukwa chake, ma modulators a silicon ndi InP electro-optic ayenera kugwiritsa ntchito bias kuti apange pn junction akamagwira ntchito, ndipo pn junction idzabweretsa kutayika kwa absorption. Komabe, kukula kwa modulator kwa awiriwa ndi kochepa, kukula kwa modulator yamalonda ya InP ndi 1/4 ya LN modulator. Kugwiritsa ntchito modulation bwino kwambiri, koyenera maukonde otumizira ma digito optical transmission akutali komanso afupi monga malo osungira deta. Mphamvu ya electro-optical ya lithium niobate ilibe njira yoyamwa kuwala komanso kutayika kochepa, komwe ndikoyenera mtunda wautali.kulankhulana kwa kuwalayokhala ndi mphamvu zambiri komanso liwiro lalikulu. Mu ntchito ya microwave photon, ma electro-optical coefficients a Si ndi InP ndi osalunjika, zomwe sizili zoyenera dongosolo la microwave photon lomwe limayesetsa kukhala ndi mzere wapamwamba komanso mphamvu zazikulu. Zipangizo za lithiamu niobate ndizoyenera kwambiri kugwiritsa ntchito microwave photon chifukwa cha mzere wake wofanana wa electro-optic modulation coefficient.
Nthawi yotumizira: Epulo-22-2024