We demonstrate a single-chip silicon optical single sideband (OSSB) modulator composed of a radio frequenc(RF) branch line coupler (BLC) and a silicon dual-parallel Mach–Zehnder modulator (DP-MZM).A co-design between...We demonstrate a single-chip silicon optical single sideband (OSSB) modulator composed of a radio frequenc(RF) branch line coupler (BLC) and a silicon dual-parallel Mach–Zehnder modulator (DP-MZM).A co-design between the BLC and the DP-MZM is implemented to improve the sideband suppression ratio (SSR).The modu lator has a modulation efficiency of V_(π)L_(π)~1.75 V·cm and a 3 dB electro-optical (EO) bandwidth of 48.7 GHz The BLC can generate a pair of RF signals with equal amplitudes and orthogonal phases at the optimal frequenc of 21 GHz.We prove through theoretical calculation and experiment that,although the BLC’s performance in terms of power balance and phase orthogonality deteriorates in a wider frequency range,high SSRs can be realized by adjusting relevant bias phases of the DP-MZM.With this technique,the undesired sidebands are completel suppressed below the noise floor in the frequency range from 15 GHz to 30 GHz when the chip operates in the ful carrier OSSB (FC-OSSB) mode.In addition,an SSR>35 dB and an carrier suppression ratio (CSR)>42 dB ar demonstrated at 21 GHz in the suppressed carrier OSSB (SC-OSSB) mode.展开更多
Graphene has attracted much attention for the realization of high-speed photodetection for silicon photonics over a wide wavelength range.However,the reported fast graphene photodetectors mainly operate in the 1.55μm...Graphene has attracted much attention for the realization of high-speed photodetection for silicon photonics over a wide wavelength range.However,the reported fast graphene photodetectors mainly operate in the 1.55μm wavelength band.In this work,we propose and realize high-performance waveguide photodetectors based on bolometric/photoconductive effects by introducing an ultrathin wide silicon−graphene hybrid plasmonic waveguide,which enables efficient light absorption in graphene at 1.55μm and beyond.When operating at 2μm,the present photodetector has a responsivity of ~70 mA/W and a setup-limited 3 dB bandwidth of >20 GHz.When operating at 1.55μm,the present photodetector also works very well with a broad 3 dB bandwidth of >40 GHz(setup-limited)and a high responsivity of ~0.4 A/W even with a low bias voltage of−0.3 V.This work paves the way for achieving highresponsivity and high-speed silicon-graphene waveguide photodetection in the near/mid-infrared ranges,which has applications in optical communications,nonlinear photonics,and on-chip sensing.展开更多
基金National Key Research and Development Program of China(2021YFB2800500)Scientific Project of Zhejiang Laboratory(2020LC0AD02)+1 种基金Science and Technology Program of Zhejiang Province(2022C01108)Science and Technology Innovation 2025 Major Project of Ningbo(2020Z021)
文摘We demonstrate a single-chip silicon optical single sideband (OSSB) modulator composed of a radio frequenc(RF) branch line coupler (BLC) and a silicon dual-parallel Mach–Zehnder modulator (DP-MZM).A co-design between the BLC and the DP-MZM is implemented to improve the sideband suppression ratio (SSR).The modu lator has a modulation efficiency of V_(π)L_(π)~1.75 V·cm and a 3 dB electro-optical (EO) bandwidth of 48.7 GHz The BLC can generate a pair of RF signals with equal amplitudes and orthogonal phases at the optimal frequenc of 21 GHz.We prove through theoretical calculation and experiment that,although the BLC’s performance in terms of power balance and phase orthogonality deteriorates in a wider frequency range,high SSRs can be realized by adjusting relevant bias phases of the DP-MZM.With this technique,the undesired sidebands are completel suppressed below the noise floor in the frequency range from 15 GHz to 30 GHz when the chip operates in the ful carrier OSSB (FC-OSSB) mode.In addition,an SSR>35 dB and an carrier suppression ratio (CSR)>42 dB ar demonstrated at 21 GHz in the suppressed carrier OSSB (SC-OSSB) mode.
基金supported by the National Major Research and Development Program(No.2018YFB2200200)National Science Fund for Distinguished Young Scholars(61725503)+2 种基金National Natural Science Foundation of China(NSFC)(61905210 and 91950205)China Postdoctoral Science Foundation(2019M662041)Zhejiang Provincial Natural Science Foundation(LZ18F050001 and LD19F050001).
文摘Graphene has attracted much attention for the realization of high-speed photodetection for silicon photonics over a wide wavelength range.However,the reported fast graphene photodetectors mainly operate in the 1.55μm wavelength band.In this work,we propose and realize high-performance waveguide photodetectors based on bolometric/photoconductive effects by introducing an ultrathin wide silicon−graphene hybrid plasmonic waveguide,which enables efficient light absorption in graphene at 1.55μm and beyond.When operating at 2μm,the present photodetector has a responsivity of ~70 mA/W and a setup-limited 3 dB bandwidth of >20 GHz.When operating at 1.55μm,the present photodetector also works very well with a broad 3 dB bandwidth of >40 GHz(setup-limited)and a high responsivity of ~0.4 A/W even with a low bias voltage of−0.3 V.This work paves the way for achieving highresponsivity and high-speed silicon-graphene waveguide photodetection in the near/mid-infrared ranges,which has applications in optical communications,nonlinear photonics,and on-chip sensing.
