High-dimensional entanglement provides valuable resources for quantum technologies,including quantum communication,quantum optical coherence tomography,and quantum computing.Obtaining a high brightness and dimensional...High-dimensional entanglement provides valuable resources for quantum technologies,including quantum communication,quantum optical coherence tomography,and quantum computing.Obtaining a high brightness and dimensional entanglement source has significant value.Here we utilize a tunable asymmetric Mach–Zehnder interferometer coupled silicon microring resonator with 100 GHz free spectral range to achieve this goal.With the strategy of the tunable coupler,the dynamical and extensive tuning range of quality factors of the microring can be obtained,and then the biphoton pair generation rate can be optimized.By selecting and characterizing 28 pairs from a more than 30-pair modes biphoton frequency comb,we obtain a Schmidt number of at least 23.4 and on-chip pair generation rate of 19.9 MHz/m W;under a low on-chip pump power,which corresponds to 547 dimensions Hilbert space in frequency freedom.These results will prompt the wide applications of quantum frequency comb and boost the further large density and scalable on-chip quantum information processing.展开更多
Quantum imaging with spatially entangled photons offers advantages such as enhanced spatial resolution,robustness against noise,and counterintuitive phenomena,while a biphoton spatial aberration generally degrades its...Quantum imaging with spatially entangled photons offers advantages such as enhanced spatial resolution,robustness against noise,and counterintuitive phenomena,while a biphoton spatial aberration generally degrades its performance.Biphoton aberration correction has been achieved by using classical beams to detect the aberration source or scanning the correction phase on biphotons if the source is unreachable.Here,a new method named position-correlated biphoton Shack-Hartmann wavefront sensing is introduced,where the phase pattern added on photon pairs with a strong position correlation is reconstructed from their position centroid distribution at the back focal plane of a microlens array.Experimentally,biphoton phase measurement and adaptive imaging against the disturbance of a plastic film are demonstrated.This single-shot method is a more direct and efficient approach toward quantum adaptive optics,suitable for integration into quantum microscopy,remote imaging,and communication.展开更多
Single-photon detection(SPD)technologies have been applied to underwater optical imaging to overcome the strong attenuation of seawater.However,external photon noise,resulting from the natural light,hinders their furt...Single-photon detection(SPD)technologies have been applied to underwater optical imaging to overcome the strong attenuation of seawater.However,external photon noise,resulting from the natural light,hinders their further applications due to the extreme sensitivity of SPD and a weakly received optical signal.In this work,we performed noise-resistant underwater correlated biphoton imaging(CPI)to partly solve the influence of the external noise,through a home-built super-bunching laser generated by the stochastic nonlinear interaction between a picosecond laser and a photonic crystal fiber.Compared with a coherent laser,the probabilities of generated bundle N-photons(N≥2)of the super-bunching laser have been enhanced by at least one order of magnitude,enabling CPI under weak light intensity.We experimentally demonstrated CPI with reasonable imaging contrast under the noise-to-signal ratio(NSR)up to 10~3,and the noise-resistant performance has been improved by at least two orders of magnitude compared to that of the single-photon imaging technology.We further achieved underwater CPI with good imaging contrast under NSR of 150,in a glass tank with a length of 10 m with Jerlov typeⅢwater(an attenuation coefficient of 0.176 m^(-1)).These results break the limits of underwater imaging through classical coherent lasers and may offer many enhanced imaging applications through our super-bunching laser,such as long-range target tracking and deep-sea optical exploration under noisy environments.展开更多
We report an all-fiber telecom-band energy-time entangled biphoton source with all physical elements integrated into a compact cabinet.At a pump power of 800μW,the photon pairs generation rate reaches 6.9 MHz with th...We report an all-fiber telecom-band energy-time entangled biphoton source with all physical elements integrated into a compact cabinet.At a pump power of 800μW,the photon pairs generation rate reaches 6.9 MHz with the coincidence-toaccidental ratio[CAR]better than 1150.The long-term stability of the biphoton source is characterized by measuring the Hong-Ou-Mandel interference visibility and CAR within a continuous operation period of more than 10 h.Benefiting from the advantages of compact size,light weight,and high stability,this device provides a convenient resource for various field turnkey quantum communication and metrology applications.展开更多
We show how quantum entangled biphoton states can be used to realize ghost scattering, a nonlocal scheme to obtain scattering information of an unknown object through the correlation measurement of the scattering phot...We show how quantum entangled biphoton states can be used to realize ghost scattering, a nonlocal scheme to obtain scattering information of an unknown object through the correlation measurement of the scattering photons in two different optical paths. We present a framework to describe the biphoton ghost scattering process from the T-matrix formula of the scattering theory. We find the scattering information of a test object can be retrieved from either the test arm or the reference arm. By adjusting the biphoton states, the ghost scattering patterns may be varied from the scattering pattern of the object in the test arm to the object in the reference arm.展开更多
基金supported by the National Basic Research Program of China(Grant Nos.2019YFA0308700 and 2017YFA0303700)the National Natural Science Foundation of China(Grant Nos.61632021 and 11690031)the Open Funds from the State Key Laboratory of High Performance Computing of China(HPCL,National University of Defense Technology)。
文摘High-dimensional entanglement provides valuable resources for quantum technologies,including quantum communication,quantum optical coherence tomography,and quantum computing.Obtaining a high brightness and dimensional entanglement source has significant value.Here we utilize a tunable asymmetric Mach–Zehnder interferometer coupled silicon microring resonator with 100 GHz free spectral range to achieve this goal.With the strategy of the tunable coupler,the dynamical and extensive tuning range of quality factors of the microring can be obtained,and then the biphoton pair generation rate can be optimized.By selecting and characterizing 28 pairs from a more than 30-pair modes biphoton frequency comb,we obtain a Schmidt number of at least 23.4 and on-chip pair generation rate of 19.9 MHz/m W;under a low on-chip pump power,which corresponds to 547 dimensions Hilbert space in frequency freedom.These results will prompt the wide applications of quantum frequency comb and boost the further large density and scalable on-chip quantum information processing.
基金funded by the Innovation Program for Quantum Science and Technology(Grant Nos.2021ZD0301200 and 2021ZD0301400)the National Natural Science Foundation of China(Grant Nos.92365205,11821404,and W2411001)the USTC Major Frontier Research Program(Grant No.LS2030000002).
文摘Quantum imaging with spatially entangled photons offers advantages such as enhanced spatial resolution,robustness against noise,and counterintuitive phenomena,while a biphoton spatial aberration generally degrades its performance.Biphoton aberration correction has been achieved by using classical beams to detect the aberration source or scanning the correction phase on biphotons if the source is unreachable.Here,a new method named position-correlated biphoton Shack-Hartmann wavefront sensing is introduced,where the phase pattern added on photon pairs with a strong position correlation is reconstructed from their position centroid distribution at the back focal plane of a microlens array.Experimentally,biphoton phase measurement and adaptive imaging against the disturbance of a plastic film are demonstrated.This single-shot method is a more direct and efficient approach toward quantum adaptive optics,suitable for integration into quantum microscopy,remote imaging,and communication.
基金supported by the National Natural Science Foundation of China(Nos.U22A2091,62222509,U23A20380,62127817,and 62205187)the Shanxi Province Science and Technology Innovation Talent Team(No.202204051001014)+2 种基金the Key Research and Development Project of Shanxi Province(No.202102030201007)the Program for Changjiang Scholars and Innovative Research Team(PCSIRT)(No.IRT_17R70)the 111 Projects(No.D18001)。
文摘Single-photon detection(SPD)technologies have been applied to underwater optical imaging to overcome the strong attenuation of seawater.However,external photon noise,resulting from the natural light,hinders their further applications due to the extreme sensitivity of SPD and a weakly received optical signal.In this work,we performed noise-resistant underwater correlated biphoton imaging(CPI)to partly solve the influence of the external noise,through a home-built super-bunching laser generated by the stochastic nonlinear interaction between a picosecond laser and a photonic crystal fiber.Compared with a coherent laser,the probabilities of generated bundle N-photons(N≥2)of the super-bunching laser have been enhanced by at least one order of magnitude,enabling CPI under weak light intensity.We experimentally demonstrated CPI with reasonable imaging contrast under the noise-to-signal ratio(NSR)up to 10~3,and the noise-resistant performance has been improved by at least two orders of magnitude compared to that of the single-photon imaging technology.We further achieved underwater CPI with good imaging contrast under NSR of 150,in a glass tank with a length of 10 m with Jerlov typeⅢwater(an attenuation coefficient of 0.176 m^(-1)).These results break the limits of underwater imaging through classical coherent lasers and may offer many enhanced imaging applications through our super-bunching laser,such as long-range target tracking and deep-sea optical exploration under noisy environments.
基金supported by the National Natural Science Foundation of China(Nos.12033007,61875205,91836301,12103058,and 61801458)the Western Young Scholar Project of CAS(Nos.XAB2019B17 and XAB2019B15)+2 种基金the Frontier Science Key Research Project of CAS(No.QYZDB-SSWSLH007)the Strategic Priority Research Program of CAS(No.XDC07020200)the Youth Innovation Promotion Association,CAS(Nos.2022413 and 2021408)。
文摘We report an all-fiber telecom-band energy-time entangled biphoton source with all physical elements integrated into a compact cabinet.At a pump power of 800μW,the photon pairs generation rate reaches 6.9 MHz with the coincidence-toaccidental ratio[CAR]better than 1150.The long-term stability of the biphoton source is characterized by measuring the Hong-Ou-Mandel interference visibility and CAR within a continuous operation period of more than 10 h.Benefiting from the advantages of compact size,light weight,and high stability,this device provides a convenient resource for various field turnkey quantum communication and metrology applications.
基金National Basic Research Program of China(2012CB921904)National Natural Science Foundation of China(NSFC)(11174084)
文摘We show how quantum entangled biphoton states can be used to realize ghost scattering, a nonlocal scheme to obtain scattering information of an unknown object through the correlation measurement of the scattering photons in two different optical paths. We present a framework to describe the biphoton ghost scattering process from the T-matrix formula of the scattering theory. We find the scattering information of a test object can be retrieved from either the test arm or the reference arm. By adjusting the biphoton states, the ghost scattering patterns may be varied from the scattering pattern of the object in the test arm to the object in the reference arm.
