In this study,we present a comprehensive thermo-optic characterization of an on-chip thin-film lithium niobate asymmetric Mach-Zehnder interferometer(aMZI)across a temperature range of 290 to 10 K.We observe that the ...In this study,we present a comprehensive thermo-optic characterization of an on-chip thin-film lithium niobate asymmetric Mach-Zehnder interferometer(aMZI)across a temperature range of 290 to 10 K.We observe that the spectral shift of the aMZI is closely associated with changes in the environmental temperature.We experimentally observed a 4.88 nm wavelength shift of the a MZI from 290 to 10 K.Moreover,the shift diminished gradually below 50 K.Our observations highlight a distinctive non-linear temperature sensitivity,particularly pronounced at cryogenic temperatures.The high-resolution setup revealed a thermo-optic coefficient as low as 5.29×10^(-8)K^(-1)at 10 K.The presented results provide new practical guidelines for designing photonic circuits for applications in cryogenic optoelectronics.展开更多
Rapid detection and discrimination of single photons are pivotal in various applications,such as deep-space laser communication,high-rate quantum key distribution,and optical quantum computation.However,conventional s...Rapid detection and discrimination of single photons are pivotal in various applications,such as deep-space laser communication,high-rate quantum key distribution,and optical quantum computation.However,conventional single-photon detectors(SPDs),including semiconducting and recently developed superconducting detectors,have limited detection speed and photon number resolution(PNR),which pose significant challenges in practical applications.In this paper,we present an efficient,fast SPD with good PNR,which has 64 paralleled,sandwiched superconducting nanowires fabricated on a distributed Bragg reflector.The detector is operated in a compact Gifford–McMahon cryocooler that supports 64 electrical channels and has a minimum working temperature of 2.3 K.The combined detector system shows a functional nanowire yield of 61/64,a system detection efficiency of 90%at 1550 nm,and a maximum count rate of 5.2 GHz.Additionally,it has a maximum PNR of 61,corresponding to the operating nanowires.This SPD signifies a substantial improvement in quantum detector technology,with potential applications in deep-space laser communication,high-speed quantum communication,and fundamental quantum optics experiments.展开更多
We report a superconducting nanowire single‐photon detector(SNSPD)array aiming for a near‐infrared 1550‐nm wavelength that consists of 32×32 nanowire pixels and an area of 0.96 mm×0.96 mm.Unlike most repo...We report a superconducting nanowire single‐photon detector(SNSPD)array aiming for a near‐infrared 1550‐nm wavelength that consists of 32×32 nanowire pixels and an area of 0.96 mm×0.96 mm.Unlike most reported large‐scale SNSPD arrays with amorphous films,NbN superconducting nanowires are employed in our array,which allows the detector operation at 2.3 K provided by a compact two‐stage Gifford–McMahon cryocooler.Thermally coupled row–column multiplexing is employed in our arrays to avoid current redistribution and loss of electrical signal occurring in the electrically coupled row–column architecture.The fabricated detector array shows a pixel yield of 94%and maximal intrinsic efficiencies of 77%and 96%at 1550 nm and 405 nm,respectively.The timing jitter and the thermal coupling probability are also investigated.展开更多
We propose and demonstrate a cryogenic thermo-optic(TO)modulator in x-cut thin-film lithium niobate(TFLN)with an NbN superconducting heater.Compared to a conventional metal heating electrode,a fast and energy-efficien...We propose and demonstrate a cryogenic thermo-optic(TO)modulator in x-cut thin-film lithium niobate(TFLN)with an NbN superconducting heater.Compared to a conventional metal heating electrode,a fast and energy-efficient modulation is obtained by placing an NbN superconducting heating electrode above the TFLN waveguide.The transition of the NbN superconducting electrode between superconducting and normal states turns the heating and cooling processes from continuous to discontinuous change.Thus,the energy consumption during the modulation process is reduced proportionally.The rise/fall time of the proposed device is 22μs/15μs,which has been the fastest response time reported in TFLN thermo-optic modulators so far.The presented TO modulator can easily be used at cryogenic temperatures and has great potential for applications in cryogenic optoelectronics.展开更多
基金supported by the Innovation Program for Quantum Science and Technology(No.2023ZD0300100)the Shanghai Municipal Science and Technology Major Project(Nos.2019SHZDZX01 and 2017SHZDZX03)+1 种基金the Strategic Priority Research Program(A)of the Chinese Academy of Sciences(No.XDA18040300)the ShanghaiTech University(Start-up funding)。
文摘In this study,we present a comprehensive thermo-optic characterization of an on-chip thin-film lithium niobate asymmetric Mach-Zehnder interferometer(aMZI)across a temperature range of 290 to 10 K.We observe that the spectral shift of the aMZI is closely associated with changes in the environmental temperature.We experimentally observed a 4.88 nm wavelength shift of the a MZI from 290 to 10 K.Moreover,the shift diminished gradually below 50 K.Our observations highlight a distinctive non-linear temperature sensitivity,particularly pronounced at cryogenic temperatures.The high-resolution setup revealed a thermo-optic coefficient as low as 5.29×10^(-8)K^(-1)at 10 K.The presented results provide new practical guidelines for designing photonic circuits for applications in cryogenic optoelectronics.
基金Innovation Program for Quantum Science and Technology(2023ZD0300100)Shanghai Sailing Program(21YF1455500,21YF1455700,22YF1456500)+2 种基金Youth Innovation Promotion Association of the Chinese Academy of Sciences(2020241,2021230)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)National Natural Science Foundation of China(12033007,61827823,61971408).
文摘Rapid detection and discrimination of single photons are pivotal in various applications,such as deep-space laser communication,high-rate quantum key distribution,and optical quantum computation.However,conventional single-photon detectors(SPDs),including semiconducting and recently developed superconducting detectors,have limited detection speed and photon number resolution(PNR),which pose significant challenges in practical applications.In this paper,we present an efficient,fast SPD with good PNR,which has 64 paralleled,sandwiched superconducting nanowires fabricated on a distributed Bragg reflector.The detector is operated in a compact Gifford–McMahon cryocooler that supports 64 electrical channels and has a minimum working temperature of 2.3 K.The combined detector system shows a functional nanowire yield of 61/64,a system detection efficiency of 90%at 1550 nm,and a maximum count rate of 5.2 GHz.Additionally,it has a maximum PNR of 61,corresponding to the operating nanowires.This SPD signifies a substantial improvement in quantum detector technology,with potential applications in deep-space laser communication,high-speed quantum communication,and fundamental quantum optics experiments.
基金the National Natural Science Foundation of China(61971408,61827823,12033007)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)+2 种基金Shanghai Rising‐Star Program(20QA1410900)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2020241)for their financial supportShanghai Sailing Program(Grants No.21YF1455700).
文摘We report a superconducting nanowire single‐photon detector(SNSPD)array aiming for a near‐infrared 1550‐nm wavelength that consists of 32×32 nanowire pixels and an area of 0.96 mm×0.96 mm.Unlike most reported large‐scale SNSPD arrays with amorphous films,NbN superconducting nanowires are employed in our array,which allows the detector operation at 2.3 K provided by a compact two‐stage Gifford–McMahon cryocooler.Thermally coupled row–column multiplexing is employed in our arrays to avoid current redistribution and loss of electrical signal occurring in the electrically coupled row–column architecture.The fabricated detector array shows a pixel yield of 94%and maximal intrinsic efficiencies of 77%and 96%at 1550 nm and 405 nm,respectively.The timing jitter and the thermal coupling probability are also investigated.
基金supported by the Shanghai Municipal Science and Technology Major Project(No.2017SHZDZX03)the Strategic Priority Research Program(A)of the Chinese Academy of Sciences(No.XDA18040300).
文摘We propose and demonstrate a cryogenic thermo-optic(TO)modulator in x-cut thin-film lithium niobate(TFLN)with an NbN superconducting heater.Compared to a conventional metal heating electrode,a fast and energy-efficient modulation is obtained by placing an NbN superconducting heating electrode above the TFLN waveguide.The transition of the NbN superconducting electrode between superconducting and normal states turns the heating and cooling processes from continuous to discontinuous change.Thus,the energy consumption during the modulation process is reduced proportionally.The rise/fall time of the proposed device is 22μs/15μs,which has been the fastest response time reported in TFLN thermo-optic modulators so far.The presented TO modulator can easily be used at cryogenic temperatures and has great potential for applications in cryogenic optoelectronics.
