Zvakanakira uye kukosha kwe thin film lithium niobate mu integrated microwave photon technology
Tekinoroji ye microwave photonine zvakanakira zvebandwidth yakakura yekushanda, kugona kwakasimba kwekugadzirisa pamwe chete uye kurasikirwa kushoma kwekutumira, izvo zvine mukana wekuputsa miganhu yehunyanzvi hwechinyakare ye microwave system uye kuvandudza mashandiro emidziyo yemagetsi yemauto senge radar, electronic warfare, kutaurirana uye kuyerwa nekudzora. Zvisinei, microwave photon system yakavakirwa pamidziyo yakasiyana ine mamwe matambudziko akadai sehuwandu hwakawanda, huremu hwakanyanya uye kusagadzikana kwakashata, izvo zvinodzikamisa zvakanyanya kushandiswa kwetekinoroji ye microwave photon mumapuratifomu emuchadenga neanobhururuka. Naizvozvo, tekinoroji ye microwave photon yakabatanidzwa iri kuva rutsigiro rwakakosha rwekuputsa kushandiswa kwe microwave photon musystem yemagetsi yemauto uye kupa mukana wakazara kune zvakanakira tekinoroji ye microwave photon.
Parizvino, tekinoroji yekubatanidza photonic yakavakirwa paSI uye tekinoroji yekubatanidza photonic yakavakirwa paINP zvave kukura zvakanyanya mushure memakore ekuvandudzwa mumunda wekutaurirana kwemaziso, uye zvigadzirwa zvakawanda zvakaiswa mumusika. Zvisinei, pakushandisa microwave photon, pane mamwe matambudziko mumhando mbiri idzi dzetekinoroji yekubatanidza photon: semuenzaniso, nonlinear electro-optical coefficient yeSi modulator neInP modulator inopesana ne high linearity uye large dynamic characteristics inoteverwa ne microwave photon technology; Semuenzaniso, silicon optical switch inoita optical path switching, ingave yakavakirwa pa thermal-optical effect, piezoelectric effect, kana carrier injection dispersion effect, ine matambudziko ekumhanya kwekuchinja zvishoma nezvishoma, kushandiswa kwesimba uye kushandiswa kwekupisa, izvo zvisingakwanise kusangana ne fast beam scanning uye large array scale microwave photon applications.
Lithium niobate yagara iri sarudzo yekutanga yemotokari inomhanya zvakanyanyamodulation yemagetsi-opticzvinhu izvi nekuda kwemhedzisiro yayo yakanaka kwazvo yemagetsi-optic. Zvisinei, lithium yechinyakare niobatemodulator yemagetsi-opticalYakagadzirwa nezvinhu zvikuru zve lithium niobate crystal, uye saizi yemudziyo uyu yakakura kwazvo, iyo isingakwanise kuzadzisa zvinodiwa ne tekinoroji ye microwave photon yakabatanidzwa. Maitiro ekubatanidza zvinhu zve lithium niobate ne linear electro-optical coefficient mu integrated microwave photon technology system yave chinangwa chevaongorori vakakodzera. Muna 2018, timu yekutsvagisa kubva kuHarvard University muUnited States yakatanga kutaura nezve tekinoroji ye photonic integration yakavakirwa pa thin film lithium niobate muNature, nekuti tekinoroji iyi ine zvakanakira zve high integration, large electro-optical modulation bandwidth, uye high linearity ye electro-optical effect, kana yangotangwa, yakabva yakonzera kutarisisa kwedzidzo neindasitiri mumunda we photonic integration uye microwave photonics. Kubva pamaonero ekushandiswa kwe microwave photon, bepa iri rinoongorora pesvedzero uye kukosha kwetekinoroji ye photon integration yakavakirwa pa thin film lithium niobate pakukura kwetekinoroji ye microwave photon.
Firimu rakatetepa re lithium niobate uye firimu rakatetepamodulator ye lithium niobate
Mumakore maviri achangopfuura, mhando itsva yezvinhu zve lithium niobate yakabuda, kureva kuti, firimu re lithium niobate rinobviswa kubva mu crystal huru ye lithium niobate nenzira ye "ion slicing" uye rinosungirirwa kuSi wafer ne silica buffer layer kuti rigadzire LNOI (LiNbO3-On-Insulator) material [5], iyo inonzi thin film lithium niobate material mupepa rino. Ridge waveguides ine urefu hweanopfuura 100 nanometers inogona kuchekwa pa thin film lithium niobate materials ne optimized dry etching process, uye effective refractive index difference yema waveguides akaumbwa inogona kusvika kupfuura 0.8 (yakakwirira kupfuura refractive index difference yema traditional lithium niobate waveguides ye 0.02), sezvakaratidzwa muMufananidzo 1. Waveguide yakaganhurirwa zvakanyanya inoita kuti zvive nyore kuenzanisa light field ne microwave field paunenge uchigadzira modulator. Saka, zvinobatsira kuwana yakaderera half-wave voltage uye yakakura modulation bandwidth muhurefu hupfupi.
Kuonekwa kwe "low loss lithium niobate submicron waveguide" kunoputsa bhodhoro re "high driving voltage" ye "traditional lithium niobate electro-optic modulator". Nzvimbo ye "electrode spacing" inogona kuderedzwa kusvika ~ 5 μm, uye kupindirana pakati pe "electric field" ne "optical mode field" kunowedzera zvakanyanya, uye "vπ · L" inoderera kubva pane anopfuura 20 V·cm kusvika pasi pe2.8 V·cm. Saka, pasi pe "half-wave voltage" imwechete, kureba kwe "device" kunogona kuderedzwa zvakanyanya kana tichienzanisa ne "traditional modulator". Panguva imwe chete, mushure mekugadzirisa parameters yehupamhi, ukobvu uye nguva ye "traveling wave electrode", sezvakaratidzwa mumufananidzo, "modulator" inogona kuva nekukwanisa kwe "ultra-high modulation bandwidth" kupfuura 100 GHz.
Mufananidzo 1 (a) wakaverengerwa kugoverwa kwemodhi uye mufananidzo we （b） wechikamu cheLN waveguide
Mufananidzo 2 （a） Waveguide uye chimiro cheelectrode uye （b） coreplate yeLN modulator
Kuenzanisa ma "thin film lithium niobate modulators" nema "traditional lithium niobate commercial modulators", ma "silicon-based modulators" uye ma "indium phosphide" (InP) modulators" uye mamwe ma "high-speed electro-optical modulators" aripo, ma "parameter" makuru ekuenzanisa anosanganisira:
(1) Chigadzirwa chehurefu hwema volts ehafu-wave (vπ ·L, V·cm), zvichiyera kushanda kwe modulation ye modulator, kukosha kwayo kudiki, kushanda kwe modulation kwakawedzera;
(2) 3 dB modulation bandwidth (GHz), iyo inoyera mhinduro yemodulator kune high-frequency modulation;
(3) Kurasikirwa kwekuisa optical (dB) munzvimbo yekuchinja modulation. Zvinogona kuonekwa kubva patafura kuti thin film lithium niobate modulator ine zvakanakira pachena mu modulation bandwidth, half-wave voltage, optical interpolation loss nezvimwewo.
Silicon, sedombo guru re integrated optoelectronics, yave kugadzirwa kusvika pari zvino, maitiro acho akura, miniaturization yayo inobatsira kubatanidzwa kukuru kwezvishandiso zvinoshanda/zvisingashande, uye modulator yayo yakadzidzwa zvakanyanya uye zvakadzama mumunda we optical communication. Electro-optical modulation mechanism yesilicon inonyanya kuve carrier depling-tion, carrier injection uye carrier accumulation. Pakati pavo, bandwidth ye modulator yakanyatsokodzera ne linear degree carrier depletion mechanism, asi nekuda kwekuti optical field distribution inowirirana ne non-uniformity ye depletion region, izvi zvinounza nonlinear second-order distortion uye third-order intermodulation distortion terms, pamwe chete ne absorption effect ye carrier pachiedza, izvo zvichatungamira kukudzikiswa kwe optical modulation amplitude uye signal distortion.
InP modulator ine mhedzisiro yakanaka ye electro-optical, uye chimiro che multi-layer quantum well chinogona kuita kuti ultra-high rate uye low driving voltage modulators ne Vπ·L kusvika 0.156V · mm. Zvisinei, kusiyana kwe refractive index ne electric field kunosanganisira linear uye nonlinear terms, uye kuwedzera kwe electric field intensity kuchaita kuti second-order effect ive pachena. Nokudaro, silicon neInP electro-optic modulators dzinofanira kushandisa bias kuti dzigadzire pn junction padzinoshanda, uye pn junction ichaita kuti absorption loss iite. Zvisinei, modulator size yeizvi zviviri idiki, commercial InP modulator size i1/4 ye LN modulator. High modulation efficiency, yakakodzera high density uye short distance digital optical transmission networks dzakadai se data centers. Electro-optical effect ye lithium niobate haina light absorption mechanism uye low loss, iyo yakakodzera long distance coherent.kutaurirana kwemazisoine simba guru uye ine mwero wakakwira. Mukushandiswa kwe microwave photon, ma electro-optical coefficients eSi neInP haana kuenzana, izvo zvisina kukodzera microwave photon system inotevedzera linearity yakakwira uye large dynamics. Chinhu che lithium niobate chakakodzera kwazvo kushandiswa kwe microwave photon nekuda kwe completely linear electro-optic modulation coefficient.
Nguva yekutumira: Kubvumbi-22-2024