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
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
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.
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.