Izinzuzo kanye nokubaluleka kwe-thin film lithium niobate kubuchwepheshe obuhlanganisiwe be-microwave photon
Ubuchwepheshe be-photon ye-microwaveinezinzuzo ze-bandwidth enkulu yokusebenza, ikhono eliqinile lokucubungula ngokulingana kanye nokulahlekelwa okuphansi kokudlulisela, okunamandla okuphula imbobo yobuchwepheshe yesistimu ye-microwave yendabuko futhi kuthuthukise ukusebenza kwemishini yolwazi lwe-elekthronikhi yezempi efana ne-radar, impi ye-elekthronikhi, ukuxhumana kanye nokulinganisa nokulawula. Kodwa-ke, uhlelo lwe-photon ye-microwave olusekelwe kumadivayisi ahlukene lunezinkinga ezithile ezifana nomthamo omkhulu, isisindo esindayo kanye nokuqina okungekuhle, okuvimbela kakhulu ukusetshenziswa kobuchwepheshe be-photon ye-microwave ezisekelweni zasemkhathini nasezindizeni. Ngakho-ke, ubuchwepheshe be-photon ye-microwave obuhlanganisiwe buba usizo olubalulekile lokuqeda ukusetshenziswa kwe-photon ye-microwave ohlelweni lolwazi lwe-elekthronikhi yezempi futhi lunikeze ukudlala okugcwele izinzuzo zobuchwepheshe be-photon ye-microwave.
Njengamanje, ubuchwepheshe bokuhlanganiswa kwe-photonic obusekelwe ku-SI kanye nobuchwepheshe bokuhlanganiswa kwe-photonic obusekelwe ku-INP sebuvuthiwe kakhulu ngemva kweminyaka eminingi yentuthuko emkhakheni wokuxhumana kwe-optical, futhi imikhiqizo eminingi ifakiwe emakethe. Kodwa-ke, ekusebenziseni i-microwave photon, kunezinkinga ezithile kulezi zinhlobo ezimbili zobuchwepheshe bokuhlanganiswa kwe-photon: isibonelo, i-nonlinear electro-optical coefficient ye-Si modulator kanye ne-InP modulator iphambene nokulingana okuphezulu kanye nezici ezinkulu eziguqukayo ezilandelwa ubuchwepheshe be-microwave photon; Isibonelo, i-silicon optical switch eqaphela ukushintsha kwendlela ye-optical, kungakhathaliseki ukuthi isekelwe kumphumela wokushisa-optical, umphumela we-piezoelectric, noma umphumela wokusabalala komjovo we-carrier, inezinkinga zesivinini sokushintsha kancane, ukusetshenziswa kwamandla kanye nokusetshenziswa kokushisa, okungenakufinyelela ukuskena okusheshayo kwe-beam kanye nezinhlelo zokusebenza ze-microwave photon zesikali esikhulu.
I-Lithium niobate ibilokhu iyisinqumo sokuqala sejubane eliphezuluukuguqulwa kwe-electro-opticizinto zokwakha ngenxa yomphumela wazo omuhle kakhulu we-electro-optic oqondile. Kodwa-ke, i-lithium niobate yendabukoi-modulator ye-electro-opticalYenziwe ngezinto ezinkulu zekristalu ye-lithium niobate, futhi usayizi wedivayisi mkhulu kakhulu, ongakwazi ukuhlangabezana nezidingo zobuchwepheshe be-photon ye-microwave ehlanganisiwe. Indlela yokuhlanganisa izinto ze-lithium niobate ne-coefficient ye-electro-optical eqondile ohlelweni lobuchwepheshe be-photon ye-microwave ehlanganisiwe sekuyinhloso yabacwaningi abafanele. Ngo-2018, ithimba locwaningo elivela eHarvard University e-United States labika okokuqala ubuchwepheshe bokuhlanganiswa kwe-photonic obusekelwe ku-lithium niobate yefilimu encane e-Nature, ngoba ubuchwepheshe bunezinzuzo zokuhlanganiswa okuphezulu, i-bandwidth enkulu ye-electro-optical modulation, kanye nokulingana okuphezulu komphumela we-electro-optical, lapho seluqalisiwe, lwabangela ngokushesha ukunaka kwezemfundo kanye nezimboni emkhakheni wokuhlanganiswa kwe-photonic kanye ne-microwave photonics. Ngokombono wokusetshenziswa kwe-microwave photon, leli phepha libuyekeza ithonya kanye nokubaluleka kobuchwepheshe bokuhlanganiswa kwe-photon obusekelwe ku-lithium niobate yefilimu encane ekuthuthukisweni kobuchwepheshe be-microwave photon.
Izinto ze-lithium niobate zefilimu encane kanye nefilimu encanei-modulator ye-lithium niobate
Eminyakeni emibili yamuva nje, kuvele uhlobo olusha lwezinto ze-lithium niobate, okungukuthi, ifilimu ye-lithium niobate ikhishwa kusuka kukristalu enkulu ye-lithium niobate ngendlela "yokusika i-ion" bese ihlanganiswa ne-Si wafer ngesendlalelo se-silica buffer ukuze kwakhiwe izinto ze-LNOI (LiNbO3-On-Insulator) [5], okubizwa ngokuthi izinto ze-lithium niobate zefilimu encane kuleli phepha. Ama-waveguides e-Ridge anokuphakama okungaphezu kwama-nanometer ayi-100 angaqoshwa ezintweni ze-lithium niobate zefilimu encane ngenqubo yokuqopha eyomile elungiselelwe kahle, futhi umehluko wenkomba yokubuyisa osebenzayo wama-waveguides akhiwe ungafinyelela ngaphezu kuka-0.8 (okuphakeme kakhulu kunomehluko wenkomba yokubuyisa wama-waveguides endabuko e-lithium niobate angu-0.02), njengoba kuboniswe kuMfanekiso 1. I-waveguides ekhawulelwe kakhulu yenza kube lula ukufanisa insimu yokukhanya nensimu ye-microwave lapho uklama i-modulator. Ngakho-ke, kuyazuzisa ukufeza i-voltage ephansi ye-half-wave kanye ne-bandwidth enkulu yokuguqula ngobude obufushane.
Ukubonakala kwe-low loss lithium niobate submicron waveguide kuphula i-bottleneck ye-high driving voltage ye-traditional lithium niobate electro-optic modulator. Isikhala se-electrode singancishiswa sibe ngu-~ 5 μm, futhi ukugqagqana phakathi kwensimu kagesi kanye nensimu yemodi ye-optical kukhuliswa kakhulu, kanti i-vπ ·L yehla kusuka ngaphezu kuka-20 V·cm kuya ngaphansi kuka-2.8 V·cm. Ngakho-ke, ngaphansi kwe-half-wave voltage efanayo, ubude bedivayisi bungancishiswa kakhulu uma kuqhathaniswa ne-modulator yendabuko. Ngesikhathi esifanayo, ngemva kokwenza ngcono amapharamitha obubanzi, ukujiya kanye nesikhawu se-traveling wave electrode, njengoba kuboniswe esithombeni, i-modulator ingaba nekhono le-bandwidth ye-modulation ephezulu kakhulu kune-100 GHz.
Isibalo 1 (a) sibalwa ukusatshalaliswa kwemodi kanye nesithombe （b） sesigaba esiphambene se-LN waveguide
Umfanekiso 2 （a） I-Waveguide kanye nesakhiwo se-electrode kanye ne-（b） i-coreplate ye-LN modulator
Ukuqhathaniswa kwama-modulators e-lithium niobate e-thin film nama-modulators ezentengiselwano ze-lithium niobate zendabuko, ama-modulators asekelwe ku-silicon kanye nama-modulators e-indium phosphide (InP) kanye namanye ama-modulators e-electro-optical asheshayo akhona, amapharamitha ayinhloko okuqhathanisa afaka:
(1) Umkhiqizo we-half-wave volt-length (vπ ·L, V·cm), olinganisa ukusebenza kahle kwe-modulator ye-modulator, lapho inani lincane, ukusebenza kahle kwe-modulator kuyanda;
(2) i-bandwidth yokuguquguquka kwe-3 dB (GHz), elinganisa impendulo ye-modulator ekuguqulweni kwemvamisa ephezulu;
(3) Ukulahlekelwa kokufakwa kwe-optical (dB) esifundeni se-modulation. Kungabonakala etafuleni ukuthi i-thin film lithium niobate modulator inezinzuzo ezisobala ku-bandwidth ye-modulation, i-voltage ye-half-wave, ukulahlekelwa kwe-optical interpolation nokunye.
I-Silicon, njengesisekelo se-optoelectronics ehlanganisiwe, isithuthukisiwe kuze kube manje, inqubo isivuthiwe, i-miniaturization yayo ihambisana nokuhlanganiswa okukhulu kwamadivayisi asebenzayo/angasebenzi, futhi i-modulator yayo ifundwe kabanzi nangokujulile emkhakheni wokuxhumana kwe-optical. Indlela yokushintshashintsha kwe-electro-optical ye-silicon ikakhulukazi iwukunciphisa i-carrier, ukujova kwe-carrier kanye nokuqongelela kwe-carrier. Phakathi kwazo, i-bandwidth ye-modulator ingcono kakhulu ngendlela yokunciphisa i-carrier ye-linear degree, kodwa ngenxa yokuthi ukusatshalaliswa kwensimu ye-optical kudlulana nokungalingani kwesifunda sokuncipha, lo mphumela uzoletha ukuphambuka kwe-nonlinear second-order kanye ne-third-order intermodulation terms, kuhlanganiswe nomphumela wokumuncwa kwe-carrier ekukhanyeni, okuzoholela ekunciphiseni kwe-amplitude ye-optical modulation kanye nokuphambuka kwesignali.
I-modulator ye-InP inemiphumela emihle kakhulu ye-electro-optical, futhi isakhiwo se-quantum well esinezingqimba eziningi singafeza ama-modulator e-voltage aphansi kakhulu kanye ne-voltage yokushayela ene-Vπ·L kuze kufike ku-0.156V · mm. Kodwa-ke, ukuhlukahluka kwe-refractive index ne-electric field kufaka phakathi amagama aqondile nangewona aqondile, futhi ukwanda kokuqina kwe-electric field kuzokwenza umphumela we-oda lesibili ubonakale. Ngakho-ke, ama-modulator e-silicon kanye ne-InP electro-optic adinga ukusebenzisa i-bias ukwakha i-pn junction lapho esebenza, futhi i-pn junction izoletha ukulahlekelwa kokumuncwa ekukhanyeni. Kodwa-ke, usayizi we-modulator walezi ezimbili mncane, usayizi we-modulator we-InP wezohwebo uyi-1/4 ye-modulator ye-LN. Ukusebenza kahle kwe-modulation ephezulu, kufanelekile kumanethiwekhi okudlulisa i-digital optical aphezulu kanye nebanga elifushane njengezikhungo zedatha. Umphumela we-electro-optical we-lithium niobate awunayo indlela yokumuncwa kokukhanya kanye nokulahleka okuphansi, okufanelekela ukuhlangana kwebanga elide.ukuxhumana okubonakalayoenomthamo omkhulu kanye nesivinini esiphezulu. Ekusetshenzisweni kwe-photon ye-microwave, ama-coefficient e-electro-optical e-Si kanye ne-InP awawona aqondile, okungafanele uhlelo lwe-photon ye-microwave olulandela umugqa ophezulu kanye ne-dynamics enkulu. Izinto ze-lithium niobate zifaneleka kakhulu ekusetshenzisweni kwe-photon ye-microwave ngenxa ye-coefficient yayo yokuguqulwa kwe-electro-optic eqondile ngokuphelele.
Isikhathi sokuthunyelwe: Ephreli-22-2024