Nyias zaj duab xis lithium niobate khoom thiab nyias zaj duab xis lithium niobate modulator

Qhov zoo thiab qhov tseem ceeb ntawm nyias zaj duab xis lithium niobate hauv kev siv tshuab microwave photon

Microwave photon technologymuaj qhov zoo ntawm kev ua haujlwm loj bandwidth, muaj peev xwm ua tau zoo sib luag thiab tsis tshua muaj kev sib kis tau zoo, uas muaj peev xwm ua kom tawg cov txheej txheem fwj ntawm cov txheej txheem microwave tsoos thiab txhim kho kev ua haujlwm ntawm cov tub rog cov ntaub ntawv hluav taws xob xws li radar, hluav taws xob ua tsov rog, kev sib txuas lus thiab kev ntsuas thiab tswj. Txawm li cas los xij, microwave photon system raws li cov khoom siv tsis sib xws muaj qee qhov teeb meem xws li ntim loj, hnyav hnyav thiab tsis muaj kev ruaj ntseg, uas txwv tsis pub siv cov tshuab microwave photon hauv qhov chaw thiab huab cua. Yog li ntawd, kev siv tshuab microwave photon tau dhau los ua ib qho kev txhawb nqa tseem ceeb los rhuav tshem daim ntawv thov ntawm microwave photon hauv tub rog cov ntaub ntawv hluav taws xob thiab muab kev ua si tag nrho rau qhov zoo ntawm microwave photon technology.

Tam sim no, SI-based photonic integration technology thiab INP-based photonic integration technology tau dhau los ua neeg paub tab tom qab xyoo ntawm kev loj hlob hauv kev sib txuas lus kho qhov muag, 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 kev koom ua ke thev naus laus zis: piv txwv li, nonlinear electro-optical coefficient ntawm Si modulator thiab InP modulator yog qhov tsis sib xws rau cov kab siab siab thiab cov yam ntxwv loj dynamic raws li microwave. photon technology; Piv txwv li, silicon optical hloov uas paub txog kev hloov kho qhov muag, txawm hais tias raws li cov nyhuv thermal-optical, piezoelectric effect, los yog cov tshuaj tua kab mob dispersion, muaj teeb meem ntawm kev hloov qeeb qeeb, kev siv hluav taws xob thiab kev siv cua sov, uas tsis tuaj yeem ua tau raws li qhov ceev ceev. beam scanning thiab loj array scale microwave photon daim ntaub ntawv.

Lithium niobate ib txwm yog thawj qhov kev xaiv rau kev kub ceevelectro-optic modulationcov ntaub ntawv vim nws zoo heev linear electro-optic nyhuv. Txawm li cas los xij, cov tsoos lithium niobateelectro-optical modulatoryog ua los ntawm cov khoom siv loj heev lithium niobate siv lead ua, thiab cov cuab yeej siv loj heev, uas tsis tuaj yeem ua tau raws li cov kev xav tau ntawm kev siv tshuab microwave photon. Yuav ua li cas koom ua ke lithium niobate cov ntaub ntawv nrog linear electro-optical coefficient rau hauv kev sib xyaw microwave photon technology system tau dhau los ua lub hom phiaj ntawm cov kws tshawb fawb. Hauv xyoo 2018, pab pawg tshawb fawb los ntawm Harvard University hauv Tebchaws Meskas tau tshaj tawm cov thev naus laus zis thev naus laus zis raws li nyias zaj duab xis lithium niobate hauv Xwm, vim tias cov thev naus laus zis muaj qhov zoo ntawm kev sib koom ua ke, loj electro-optical modulation bandwidth, thiab siab linearity ntawm electro -optical nyhuv, ib zaug launched, nws tam sim ntawd ua rau kev kawm thiab kev lag luam mloog nyob rau hauv lub tshav pob ntawm photonic integration thiab microwave photonics. Los ntawm qhov kev xav ntawm daim ntawv thov microwave photon, daim ntawv no tshuaj xyuas qhov cuam tshuam thiab qhov tseem ceeb ntawm photon kev koom ua ke thev naus laus zis raws li nyias zaj duab xis lithium niobate ntawm kev txhim kho microwave photon technology.

Nyias zaj duab xis lithium niobate khoom thiab nyias zaj duab xisLithium niobate modulator
Nyob rau hauv ob xyoos tsis ntev los no, ib hom tshiab ntawm lithium niobate cov ntaub ntawv tau tshwm sim, uas yog, lithium niobate zaj duab xis yog exfoliated los ntawm loj lithium niobate siv lead ua los ntawm txoj kev "ion slicing" thiab bonded rau Si wafer nrog ib tug silica tsis txheej rau. daim ntawv LNOI (LiNbO3-On-Insulator) cov ntaub ntawv [5], uas yog hu ua nyias zaj duab xis lithium niobate khoom nyob rau hauv daim ntawv no. Ridge waveguides nrog qhov siab ntawm ntau tshaj 100 nanometers tuaj yeem etched ntawm nyias zaj duab xis lithium niobate cov ntaub ntawv los ntawm optimized qhuav etching txheej txheem, thiab qhov zoo refractive index sib txawv ntawm cov waveguides tsim tuaj yeem ncav cuag ntau tshaj 0.8 (dav siab tshaj qhov refractive index sib txawv ntawm cov tsoos). lithium niobate waveguides ntawm 0.02), raws li qhia nyob rau hauv daim duab 1. Lub zog txwv waveguide ua rau nws yooj yim dua kom phim lub teeb teb nrog lub microwave teb thaum tsim lub modulator. Yog li, nws tau txais txiaj ntsig kom ua tiav qhov qis dua ib nrab-yoj voltage thiab loj dua kev hloov pauv bandwidth nyob rau hauv luv luv.

Cov tsos ntawm cov tsis tshua muaj lithium niobate submicron waveguide tawg lub bottleneck ntawm high tsav voltage ntawm tsoos lithium niobate electro-optic modulator. Qhov sib nrug ntawm electrode tuaj yeem txo qis mus rau ~ 5 μm, thiab qhov sib tshooj ntawm qhov hluav taws xob thiab qhov chaw kho qhov muag pom tau zoo heev, thiab vπ·L txo 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-yoj, qhov ntev ntawm lub cuab yeej tuaj yeem txo qis heev piv nrog cov tshuaj modulator. Nyob rau tib lub sijhawm, tom qab ua kom zoo dua qhov tsis muaj qhov dav, tuab thiab lub sijhawm ntawm kev mus ncig yoj electrode, raws li qhia hauv daim duab, tus modulator tuaj yeem muaj peev xwm ntawm ultra-high modulation bandwidth ntau dua 100 GHz.

Fig.1 (a) suav hom kev faib tawm thiab (b) duab ntawm ntu ntu ntawm LN waveguide

Fig.2 (a) Waveguide thiab electrode qauv thiab (b) coreplate ntawm LN modulator

Kev sib piv ntawm nyias zaj duab xis lithium niobate modulators nrog tsoos lithium niobate coj mus muag modulators, silicon-raws li modulators thiab indium phosphide (InP) modulators thiab lwm yam uas twb muaj lawm high-speed electro-optical modulators, lub ntsiab tsis zoo ntawm kev sib piv muaj xws li:
(1) Ib nrab-yoj volt-ntev cov khoom (vπ·L, V·cm), ntsuas qhov kev ua tau zoo ntawm cov modulator, qhov me dua tus nqi, qhov siab dua qhov kev ua haujlwm zoo;
(2) 3 dB modulation bandwidth (GHz), uas ntsuas cov lus teb ntawm lub modulator rau high-frequency modulation;
(3) Optical insertion poob (dB) hauv cheeb tsam modulation. Nws tuaj yeem pom los ntawm lub rooj hais tias nyias zaj duab xis lithium niobate modulator muaj qhov pom tseeb zoo hauv kev hloov pauv bandwidth, ib nrab-yoj voltage, optical interpolation poob thiab lwm yam.

Silicon, raws li lub hauv paus ntawm kev sib koom ua ke optoelectronics, tau tsim los txog tam sim no, cov txheej txheem yog cov paub tab, nws cov miniaturization yog qhov tsim nyog rau kev sib koom ua ke loj ntawm cov khoom siv hluav taws xob / passive, thiab nws cov modulator tau kawm dav thiab tob hauv kev kho qhov muag. kev sib txuas lus. Electro-optical modulation mechanism ntawm silicon feem ntau yog cov cab cab depling-tion, cov cab cab thiab cov khoom thauj. Ntawm lawv, qhov bandwidth ntawm lub modulator yog qhov zoo tshaj plaws nrog rau cov kab ntawv kab ke kev ua haujlwm depletion mechanism, tab sis vim hais tias qhov chaw kho qhov muag faib sib tshooj nrog qhov tsis sib xws ntawm cheeb tsam depletion, cov nyhuv no yuav qhia qhov tsis sib xws ntawm qhov kev txiav txim thib ob thiab qhov kev txiav txim thib peb intermodulation distortion. cov ntsiab lus, ua ke nrog cov nyhuv nqus ntawm cov cab kuj ntawm lub teeb, uas yuav ua rau txo qis ntawm qhov kev hloov kho qhov muag amplitude thiab teeb liab distortion.

InP modulator muaj cov teebmeem zoo electro-optical, thiab cov txheej txheem ntau txheej quantum zoo tuaj yeem paub txog tus nqi siab thiab tsis tshua muaj tsav tsheb voltage modulators nrog Vπ·L txog 0.156V · mm. Txawm li cas los xij, qhov sib txawv ntawm qhov ntsuas qhov ntsuas hluav taws xob nrog hluav taws xob suav nrog cov ntsiab lus linear thiab nonlinear, thiab qhov nce ntawm hluav taws xob siv hluav taws xob yuav ua rau qhov kev txiav txim thib ob tseem ceeb. Yog li ntawd, silicon thiab InP electro-optic modulators yuav tsum tau siv kev tsis ncaj ncees los tsim pn hlws ris thaum lawv ua haujlwm, thiab pn kev sib tshuam yuav ua rau lub teeb poob. Txawm li cas los xij, qhov modulator loj ntawm ob qho no me me, kev lag luam InP modulator loj yog 1/4 ntawm LN modulator. High modulation efficiency, haum rau siab ceev thiab luv nrug digital optical transmission networks xws li cov chaw zov me nyuam. Cov nyhuv electro-optical ntawm lithium niobate tsis muaj teeb pom kev zoo thiab poob qis, uas tsim nyog rau kev sib txuas ntev ntev.optical kev sib txuas lusnrog lub peev xwm loj thiab tus nqi siab. Nyob rau hauv daim ntawv thov microwave photon, cov electro-optical coefficients ntawm Si thiab InP yog nonlinear, uas tsis haum rau lub microwave photon system uas nrhiav siab linearity thiab loj dynamics. Cov khoom siv lithium niobate yog qhov tsim nyog rau daim ntawv thov microwave photon vim nws cov kab hluav taws xob ua hluav taws xob ua kom pom tseeb coefficient.