On-chip superconducting nanowire single-photon detectors(SNSPDs)are gaining traction in integrated quantum photonics due to their exceptional performance and the elimination of fiber coupling loss.However,off-chip hig...On-chip superconducting nanowire single-photon detectors(SNSPDs)are gaining traction in integrated quantum photonics due to their exceptional performance and the elimination of fiber coupling loss.However,off-chip high-rejection filters are commonly required to remove the intense pump light employed in quantum states generation,thus remaining the obstacle for embedding SNSPDs into quantum photonic circuits.Here,we explore the integration of SNSPDs with passive pump rejection filters,achieved by cascaded silicon Bragg gratings,on a single substrate.Serving as an entanglement receiver chip,the integrated components show a system detection efficiency of 20.1%and a pump rejection ratio of approximately 56 dB.We successfully verify energy-time entangled photon pairs from a microring resonator with raw visibilities of 92.85%±5.95%and 91.91%±7.34%under two nonorthogonal bases,with use of standard fiber wavelength demultiplexers.Our results pave the way for entanglement resource distribution,offering a promising approach toward the construction of large-scale quantum photonic systems.展开更多
In this study,we investigate the impact of substrates with distributed Bragg reflectors(DBRs)on the proximity effect during the fabrication of superconducting nanowire single-photon detectors(SNSPDs)using electron bea...In this study,we investigate the impact of substrates with distributed Bragg reflectors(DBRs)on the proximity effect during the fabrication of superconducting nanowire single-photon detectors(SNSPDs)using electron beam lithography.We compare the linewidth compression and line edge roughness of nanowires prepared on three different DBRs substrates.Additionally,we characterize the variations in switching current(I_(sw))and intrinsic detection efficiency(IDE)at a 2.2-K temperature.The results show that when the substrates are composed of low atomic number materials,such as Si and SiO2,the proximity effect is significantly mitigated.As a consequence,the lithography quality of nanowires is effectively improved,thus enhancing the IDE of SNSPDs.This study is expected to provide new insights into the fabrication of SNSPDs and lay the foundation for the preparation of high-performance and high-uniformity large-area devices.展开更多
基金Innovation Program for Quantum Science and Technology(2023ZD0300100)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)+1 种基金National Natural Science Foundation of China(61971408,12033007,92365210,U24A20320)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2020241,2021230)。
文摘On-chip superconducting nanowire single-photon detectors(SNSPDs)are gaining traction in integrated quantum photonics due to their exceptional performance and the elimination of fiber coupling loss.However,off-chip high-rejection filters are commonly required to remove the intense pump light employed in quantum states generation,thus remaining the obstacle for embedding SNSPDs into quantum photonic circuits.Here,we explore the integration of SNSPDs with passive pump rejection filters,achieved by cascaded silicon Bragg gratings,on a single substrate.Serving as an entanglement receiver chip,the integrated components show a system detection efficiency of 20.1%and a pump rejection ratio of approximately 56 dB.We successfully verify energy-time entangled photon pairs from a microring resonator with raw visibilities of 92.85%±5.95%and 91.91%±7.34%under two nonorthogonal bases,with use of standard fiber wavelength demultiplexers.Our results pave the way for entanglement resource distribution,offering a promising approach toward the construction of large-scale quantum photonic systems.
基金Innovation Program for Quantum Science and Technology(No.2023ZD0300100)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)National Natural Science Foundation of China(U24A20320,and 12033007)for their financial support.
文摘In this study,we investigate the impact of substrates with distributed Bragg reflectors(DBRs)on the proximity effect during the fabrication of superconducting nanowire single-photon detectors(SNSPDs)using electron beam lithography.We compare the linewidth compression and line edge roughness of nanowires prepared on three different DBRs substrates.Additionally,we characterize the variations in switching current(I_(sw))and intrinsic detection efficiency(IDE)at a 2.2-K temperature.The results show that when the substrates are composed of low atomic number materials,such as Si and SiO2,the proximity effect is significantly mitigated.As a consequence,the lithography quality of nanowires is effectively improved,thus enhancing the IDE of SNSPDs.This study is expected to provide new insights into the fabrication of SNSPDs and lay the foundation for the preparation of high-performance and high-uniformity large-area devices.
