Kuti mulumikizane mwachangu, modulator ya IQ yokhala ndi silicon yochokera ku optoelectronic yolumikizidwa ndi silicon

Optoelectronic yochokera ku silicon yaying'onoChowongolera cha IQkuti mulumikizane mwachangu kwambiri
Kufunika kwakukulu kwa kutumiza deta komanso ma transceiver osagwiritsa ntchito mphamvu zambiri m'malo osungira deta kwapangitsa kuti pakhale magwiridwe antchito ang'onoang'ono.ma modulators a kuwalaUkadaulo wa optoelectronic wozikidwa pa silicon (SiPh) wakhala nsanja yabwino yolumikizira zigawo zosiyanasiyana za photonic pa chip imodzi, zomwe zimathandiza kuti pakhale mayankho ocheperako komanso otsika mtengo. Nkhaniyi ifufuza njira yatsopano yoyendetsera silicon IQ modulator yozikidwa pa GeSi EAMs, yomwe imatha kugwira ntchito pafupipafupi mpaka 75 Gbaud.
Kapangidwe ka chipangizo ndi makhalidwe ake
Chowongolera cha IQ chomwe chikuganiziridwa chimagwiritsa ntchito kapangidwe kakang'ono ka mikono itatu, monga momwe zasonyezedwera pa Chithunzi 1 (a). Chopangidwa ndi ma GeSi EAM atatu ndi ma thermo optical phase shifter atatu, zomwe zimagwiritsa ntchito mawonekedwe ofanana. Kuwala kolowera kumalumikizidwa mu chip kudzera mu grating coupler (GC) ndikugawidwa mofanana m'njira zitatu kudzera mu 1×3 multimode interferometer (MMI). Pambuyo podutsa mu modulator ndi phase shifter, kuwalako kumaphatikizidwanso ndi 1×3 MMI ina kenako kumalumikizidwa ku single-mode fiber (SSMF).

Chithunzi 1: (a) Chithunzi cha microscopic cha IQ modulator; (b) – (d) EO S21, extinction ratio spectrum, ndi transmittance ya GeSi EAM imodzi; (e) Schematic diagram ya IQ modulator ndi optical phase shifter yofanana; (f) Carrier suppression representation on the complex plane. Monga momwe zasonyezedwera mu Chithunzi 1 (b), GeSi EAM ili ndi wide electro-optic bandwidth. Chithunzi 1 (b) anayeza S21 parameter ya single GeSi EAM test structure pogwiritsa ntchito 67 GHz optical component analyzer (LCA). Zithunzi 1 (c) ndi 1 (d) motsatana zikuwonetsa static extinction ratio (ER) spectra pa DC voltages zosiyanasiyana ndi transmission pa wavelength ya 1555 nanometers.
Monga momwe zasonyezedwera pa Chithunzi 1 (e), chinthu chachikulu chomwe chimachitika pa kapangidwe kameneka ndi kuthekera koletsa zonyamulira za kuwala posintha chosinthira cha phase chomwe chili pakati pa mkono wapakati. Kusiyana kwa gawo pakati pa mikono yapamwamba ndi yapansi ndi π/2, komwe kumagwiritsidwa ntchito pokonza zovuta, pomwe kusiyana kwa gawo pakati pa mkono wapakati ndi -3 π/4. Kapangidwe kameneka kamalola kusokoneza kowononga kwa chonyamulira, monga momwe zasonyezedwera mu ndege yovuta ya Chithunzi 1 (f).
Kukhazikitsa koyesera ndi zotsatira zake
Kukhazikitsa koyeserera kwachangu kwambiri kwawonetsedwa mu Chithunzi 2 (a). Jenereta ya mafunde osasinthika (Keysight M8194A) imagwiritsidwa ntchito ngati gwero la chizindikiro, ndipo ma amplifiers awiri a 60 GHz ofanana ndi gawo la RF (okhala ndi ma tees ophatikizidwa a bias) amagwiritsidwa ntchito ngati ma modulator oyendetsa. Voltage ya bias ya GeSi EAM ndi -2.5 V, ndipo chingwe cha RF chogwirizana ndi gawo chimagwiritsidwa ntchito kuchepetsa kusalingana kwa gawo lamagetsi pakati pa njira za I ndi Q.
Chithunzi 2: (a) Kukhazikitsa koyeserera kwachangu kwambiri, (b) Kuchepetsa chonyamulira pa 70 Gbaud, (c) Kuchuluka kwa zolakwika ndi kuchuluka kwa deta, (d) Kuwunika kwa nyenyezi pa 70 Gbaud. Gwiritsani ntchito laser yakunja yamalonda (ECL) yokhala ndi mzere wa 100 kHz, kutalika kwa 1555 nm, ndi mphamvu ya 12 dBm ngati chonyamulira chowunikira. Pambuyo pa kusintha, chizindikiro cha kuwala chimakulitsidwa pogwiritsa ntchitochokulitsa cha ulusi chopangidwa ndi erbium(EDFA) kuti athetse kutayika kwa ma coupling pa chip ndi kutayika kwa modulator insertion.
Pamapeto pake, Optical Spectrum Analyzer (OSA) imayang'anira ma signal spectrum ndi carrier restrainment, monga momwe zasonyezedwera pa Chithunzi 2 (b) kuti ipeze chizindikiro cha 70 Gbaud. Gwiritsani ntchito cholandirira cholumikizira cha polarization coherent kuti mulandire ma signal, chomwe chili ndi 90 degrees optical mixer ndi zinayi.Ma photodiode olinganizidwa a 40 GHz, ndipo imalumikizidwa ku oscilloscope ya 33 GHz, 80 GSa/s nthawi yeniyeni (RTO) (Keysight DSOZ634A). Gwero lachiwiri la ECL lokhala ndi mzere wopingasa wa 100 kHz limagwiritsidwa ntchito ngati oscillator yapafupi (LO). Chifukwa cha transmitter yomwe imagwira ntchito pansi pa mikhalidwe ya polarization imodzi, njira ziwiri zamagetsi zokha ndi zomwe zimagwiritsidwa ntchito posinthira analog-to-digital (ADC). Deta imalembedwa pa RTO ndikukonzedwa pogwiritsa ntchito purosesa ya digito ya offline (DSP).
Monga momwe zasonyezedwera pa Chithunzi 2 (c), IQ modulator idayesedwa pogwiritsa ntchito mtundu wa QPSK modulation kuyambira 40 Gbaud mpaka 75 Gbaud. Zotsatira zake zikusonyeza kuti pansi pa 7% hard decision forward error correction (HD-FEC) mikhalidwe, liwiro likhoza kufika 140 Gb/s; Pansi pa 20% soft decision forward error correction (SD-FEC), liwiro likhoza kufika 150 Gb/s. Chithunzi cha nyenyezi pa 70 Gbaud chikuwonetsedwa pa Chithunzi 2 (d). Zotsatira zake zimachepetsedwa ndi oscilloscope bandwidth ya 33 GHz, yomwe ndi yofanana ndi signal bandwidth ya pafupifupi 66 Gbaud.

Monga momwe zasonyezedwera pa Chithunzi 2 (b), kapangidwe ka mikono itatu kangathe kuletsa bwino zonyamulira za kuwala ndi chiŵerengero chopanda kanthu chopitirira 30 dB. Kapangidwe kameneka sikafuna kuletsa kotheratu chonyamulira ndipo kangagwiritsidwenso ntchito m'ma receiver omwe amafunikira ma toni a carrier kuti abwezeretse zizindikiro, monga Kramer Kronig (KK) receivers. Chonyamuliracho chikhoza kusinthidwa kudzera mu central arm phase shifter kuti chikwaniritse chiŵerengero cha carrier to sideband chomwe chikufunidwa (CSR).
Ubwino ndi Mapulogalamu
Poyerekeza ndi ma modulators achikhalidwe a Mach Zehnder (Ma modulators a MZM) ndi ma modulators ena a IQ optoelectronic opangidwa ndi silicon, modulator ya silicon IQ yomwe ikuperekedwa ili ndi zabwino zambiri. Choyamba, ndi yaying'ono kukula kwake, yocheperako nthawi zoposa 10 kuposa ma modulators a IQ kutengeraMach Zehnder modulators(kupatula ma bonding pads), motero kumawonjezera kuchulukana kwa integration ndikuchepetsa malo a chip. Kachiwiri, kapangidwe ka electrode yolumikizidwa sikufuna kugwiritsa ntchito ma terminal resistors, motero kumachepetsa capacitance ya chipangizo ndi mphamvu pa bit. Kachitatu, mphamvu yoletsa carrier imakulitsa kuchepetsa mphamvu yotumizira, ndikuwonjezera kugwiritsa ntchito mphamvu moyenera.
Kuphatikiza apo, bandwidth yowala ya GeSi EAM ndi yayikulu kwambiri (yoposa ma nanometer 30), zomwe zimapangitsa kuti pasakhale kufunikira kwa ma circuits ndi ma processors ambiri kuti akhazikitse ndikulumikiza ma resonance a ma microwave modulators (MRMs), motero kupangitsa kuti kapangidwe kake kakhale kosavuta.
Chojambulira cha IQ chogwira ntchito bwinochi n'choyenera kwambiri kwa ma transceivers a m'badwo wotsatira, kuchuluka kwa njira zambiri, komanso ma transceivers ang'onoang'ono ogwirizana m'malo osungira deta, zomwe zimathandiza kuti pakhale mphamvu zambiri komanso kulumikizana kwa kuwala kogwiritsa ntchito mphamvu zambiri.
Chojambulira cha silicon IQ choponderezedwa chimagwira ntchito bwino kwambiri, ndi liwiro lotumizira deta mpaka 150 Gb/s pansi pa 20% SD-FEC. Kapangidwe kake kakang'ono ka mikono itatu kochokera ku GeSi EAM kali ndi ubwino waukulu pankhani ya mapazi, kugwiritsa ntchito mphamvu moyenera, komanso kuphweka kwa kapangidwe. Chojambulira ichi chili ndi mphamvu yoletsa kapena kusintha chojambulira cha kuwala ndipo chikhoza kuphatikizidwa ndi kuzindikira kogwirizana komanso njira zodziwira Kramer Kronig (KK) za ma transceiver ogwirizana okhala ndi mizere yambiri. Zomwe zawonetsedwa zikuyendetsa kukwaniritsidwa kwa ma transceiver opangidwa bwino kwambiri komanso ogwira ntchito bwino kuti akwaniritse kufunikira kwakukulu kwa kulumikizana kwa deta m'malo osungira deta ndi madera ena.