Cov txiaj ntsig thiab qhov tseem ceeb ntawm cov zaj duab xis nyias lithium niobate hauv kev siv tshuab microwave photon sib xyaw ua ke
Kev siv tshuab microwave photonmuaj qhov zoo ntawm kev ua haujlwm bandwidth loj, muaj peev xwm ua tiav parallel muaj zog thiab kev poob qis, uas muaj peev xwm rhuav tshem qhov kev txwv ntawm cov txheej txheem microwave ib txwm muaj thiab txhim kho kev ua haujlwm ntawm cov khoom siv hluav taws xob tub rog xws li radar, kev ua tsov rog hluav taws xob, kev sib txuas lus thiab kev ntsuas thiab kev tswj hwm. Txawm li cas los xij, lub microwave photon system raws li cov khoom siv sib cais muaj qee qhov teeb meem xws li ntim loj, hnyav thiab tsis ruaj khov, uas txwv tsis pub siv cov thev naus laus zis microwave photon hauv cov chaw dav hlau thiab cov dav hlau. Yog li ntawd, kev sib xyaw ua ke microwave photon thev naus laus zis tau dhau los ua kev txhawb nqa tseem ceeb los rhuav tshem kev siv microwave photon hauv cov tub rog cov ntaub ntawv hluav taws xob thiab muab kev ua si tag nrho rau qhov zoo ntawm microwave photon thev naus laus zis.
Tam sim no, SI-based photonic integration technology thiab INP-based photonic integration technology tau dhau los ua neeg laus dua tom qab ntau xyoo ntawm kev txhim kho hauv kev sib txuas lus optical, thiab ntau yam khoom tau muab tso rau hauv kev ua lag luam. Txawm li cas los xij, rau daim ntawv thov ntawm microwave photon, muaj qee qhov teeb meem hauv ob hom photon integration technologies no: piv txwv li, cov coefficient nonlinear electro-optical ntawm Si modulator thiab InP modulator yog qhov tsis sib xws rau cov yam ntxwv siab linearity thiab cov yam ntxwv loj dynamic uas tau ua los ntawm microwave photon technology; Piv txwv li, lub silicon optical switch uas paub txog kev hloov pauv txoj kev optical, txawm tias raws li thermal-optical effect, piezoelectric effect, lossis carrier injection dispersion effect, muaj teeb meem ntawm kev hloov qeeb, kev siv hluav taws xob thiab kev siv cua sov, uas tsis tuaj yeem ua tau raws li kev ntsuas ceev ceev thiab cov ntawv thov microwave photon loj.
Lithium niobate yeej ib txwm yog thawj qhov kev xaiv rau kev kub ceevkev hloov kho hluav taws xobcov ntaub ntawv vim nws cov nyhuv electro-optic zoo heev. Txawm li cas los xij, cov lithium niobate ib txwm muajelectro-optical modulatoryog ua los ntawm cov khoom siv lithium niobate loj heev, thiab qhov loj ntawm lub cuab yeej loj heev, uas tsis tuaj yeem ua tau raws li qhov xav tau ntawm kev siv tshuab microwave photon. Yuav ua li cas koom ua ke cov khoom siv lithium niobate nrog cov coefficient electro-optical linear rau hauv lub tshuab microwave photon technology system tau dhau los ua lub hom phiaj ntawm cov kws tshawb fawb cuam tshuam. Xyoo 2018, pab pawg tshawb fawb los ntawm Harvard University hauv Tebchaws Meskas tau tshaj tawm thawj zaug txog kev siv tshuab photonic integration raws li cov zaj duab xis nyias lithium niobate hauv Nature, vim tias cov thev naus laus zis muaj qhov zoo ntawm kev koom ua ke siab, cov bandwidth electro-optical modulation loj, thiab cov nyhuv electro-optical linearity siab, thaum tso tawm, nws tam sim ntawd ua rau kev kawm thiab kev lag luam saib xyuas hauv thaj chaw ntawm kev koom ua ke photonic thiab microwave photonics. Los ntawm qhov kev xav ntawm kev siv microwave photon, daim ntawv no tshuaj xyuas qhov cuam tshuam thiab qhov tseem ceeb ntawm kev siv tshuab photon integration raws li cov zaj duab xis nyias lithium niobate rau kev txhim kho microwave photon technology.
Cov khoom siv lithium niobate nyias zaj duab xis thiab zaj duab xis nyiaslithium niobate modulator
Ob xyoos dhau los no, ib hom khoom siv lithium niobate tshiab tau tshwm sim, uas yog, zaj duab xis lithium niobate raug tshem tawm ntawm cov lithium niobate crystal loj heev los ntawm txoj kev "ion slicing" thiab txuas nrog Si wafer nrog ib txheej silica buffer los tsim LNOI (LiNbO3-On-Insulator) cov khoom siv [5], uas hu ua cov khoom siv lithium niobate nyias nyias hauv daim ntawv no. Ridge waveguides nrog qhov siab ntau dua 100 nanometers tuaj yeem etched rau ntawm cov khoom siv lithium niobate nyias nyias los ntawm cov txheej txheem etching qhuav zoo, thiab qhov sib txawv ntawm cov refractive index ntawm cov waveguides tsim tuaj yeem ncav cuag ntau dua 0.8 (siab dua qhov sib txawv ntawm cov refractive index ntawm cov lithium niobate waveguides ib txwm muaj ntawm 0.02), raws li pom hauv Daim Duab 1. Lub waveguide txwv tsis pub ua rau nws yooj yim dua los phim lub teeb teb nrog lub microwave teb thaum tsim lub modulator. Yog li, nws yog qhov zoo kom ua tiav qhov hluav taws xob ib nrab nthwv dej qis dua thiab cov modulation bandwidth loj dua hauv qhov ntev luv dua.
Qhov tshwm sim ntawm cov lithium niobate submicron waveguide uas poob qis ua rau lub qhov rooj ntawm lub zog tsav tsheb siab ntawm cov lithium niobate electro-optic modulator ib txwm muaj. Qhov sib nrug ntawm electrode tuaj yeem txo kom txog ~ 5 μm, thiab qhov sib tshooj ntawm lub teb hluav taws xob thiab lub teb hom optical tau nce ntxiv ntau heev, thiab vπ · L txo qis los ntawm ntau dua 20 V · cm mus rau tsawg dua 2.8 V · cm. Yog li ntawd, nyob rau hauv tib lub zog ib nrab nthwv dej, qhov ntev ntawm lub cuab yeej tuaj yeem txo qis ntau piv rau cov modulator ib txwm muaj. Tib lub sijhawm, tom qab ua kom zoo dua cov kev txwv ntawm qhov dav, tuab thiab lub sijhawm ntawm lub electrode nthwv dej mus ncig, raws li pom hauv daim duab, lub modulator tuaj yeem muaj peev xwm ntawm ultra-high modulation bandwidth ntau dua 100 GHz.
Daim Duab 1 (a) kev faib tawm hom xam thiab (b) daim duab ntawm qhov seem ntawm LN waveguide
Daim Duab 2 (a) Waveguide thiab electrode qauv thiab (b) coreplate ntawm LN modulator
Kev sib piv ntawm cov lithium niobate modulators nyias zaj duab xis nrog cov lithium niobate commercial modulators, silicon-based modulators thiab indium phosphide (InP) modulators thiab lwm yam high-speed electro-optical modulators uas twb muaj lawm, cov yam ntxwv tseem ceeb ntawm kev sib piv suav nrog:
(1) Ib nrab-nthwv dej volt-ntev khoom (vπ · L, V · cm), ntsuas qhov kev ua haujlwm ntawm modulator, qhov me dua tus nqi, qhov siab dua qhov kev ua haujlwm ntawm modulation;
(2) 3 dB modulation bandwidth (GHz), uas ntsuas qhov teb ntawm lub modulator rau high-frequency modulation;
(3) Kev poob ntawm qhov muag (dB) hauv thaj chaw modulation. Nws tuaj yeem pom los ntawm lub rooj tias cov zaj duab xis nyias lithium niobate modulator muaj qhov zoo pom tseeb hauv modulation bandwidth, ib nrab-wave voltage, optical interpolation poob thiab lwm yam.
Silicon, ua lub hauv paus ntawm kev sib xyaw ua ke ntawm optoelectronics, tau tsim kho kom deb li deb, cov txheej txheem tau loj hlob, nws qhov me me yog qhov zoo rau kev sib koom ua ke loj ntawm cov khoom siv nquag / tsis muaj zog, thiab nws cov modulator tau kawm dav thiab tob hauv kev sib txuas lus optical. Lub tshuab electro-optical modulation ntawm silicon yog feem ntau yog carrier depling-tion, carrier txhaj tshuaj thiab carrier accumulation. Ntawm lawv, bandwidth ntawm modulator yog qhov zoo tshaj plaws nrog lub tshuab linear degree carrier depletion, tab sis vim tias qhov kev faib tawm ntawm lub teb optical overlaps nrog qhov tsis sib xws ntawm thaj chaw depletion, qhov cuam tshuam no yuav ua rau muaj kev cuam tshuam thib ob thiab thib peb intermodulation distortion cov nqe lus, ua ke nrog cov nyhuv nqus ntawm carrier ntawm lub teeb, uas yuav ua rau txo qis ntawm optical modulation amplitude thiab teeb liab distortion.
Tus InP modulator muaj cov teebmeem electro-optical zoo heev, thiab cov qauv ntau txheej quantum zoo tuaj yeem ua tiav ultra-high rate thiab qis tsav voltage modulators nrog Vπ·L txog li 0.156V · mm. Txawm li cas los xij, qhov sib txawv ntawm refractive index nrog lub teb hluav taws xob suav nrog cov lus linear thiab nonlinear, thiab qhov nce ntawm lub zog hluav taws xob yuav ua rau qhov thib ob-txheej txheem cuam tshuam. Yog li ntawd, silicon thiab InP electro-optic modulators yuav tsum siv bias los tsim pn junction thaum lawv ua haujlwm, thiab pn junction yuav coj kev poob dej mus rau lub teeb. Txawm li cas los xij, qhov loj me ntawm modulator ntawm ob qho no yog me me, qhov loj me ntawm InP modulator lag luam yog 1/4 ntawm LN modulator. Kev ua haujlwm siab modulation, haum rau qhov ceev ceev thiab luv luv digital optical kis networks xws li cov chaw khaws ntaub ntawv. Cov nyhuv electro-optical ntawm lithium niobate tsis muaj lub tshuab nqus lub teeb thiab poob qis, uas yog haum rau kev sib raug zoo ntev.kev sib txuas lus pom kevnrog lub peev xwm loj thiab tus nqi siab. Hauv daim ntawv thov microwave photon, cov coefficients electro-optical ntawm Si thiab InP yog nonlinear, uas tsis haum rau lub microwave photon system uas nrhiav kev linearity siab thiab dynamics loj. Cov khoom siv lithium niobate yog qhov tsim nyog heev rau daim ntawv thov microwave photon vim nws cov coefficient modulation electro-optic linear tag nrho.
Lub sijhawm tshaj tawm: Plaub Hlis-22-2024