Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which woul...Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.展开更多
We show that the secret key generation rate can be balanced with the maximum secure distance of four-state continuous-variable quantum key distribution（CV-QKD） by using the linear optics cloning machine（LOCM）. Ben...We show that the secret key generation rate can be balanced with the maximum secure distance of four-state continuous-variable quantum key distribution（CV-QKD） by using the linear optics cloning machine（LOCM）. Benefiting from the LOCM operation, the LOCM-tuned noise can be employed by the reference partner of reconciliation to achieve higher secret key generation rates over a long distance. Simulation results show that the LOCM operation can flexibly regulate the secret key generation rate and the maximum secure distance and improve the performance of four-state CV-QKD protocol by dynamically tuning parameters in an appropriate range.展开更多
The transportable optical clock can be deployed in various transportation vehicles,including aviation,aerospace,maritime,and land-based vehicles;provides remote time standards for geophysical monitoring and distribute...The transportable optical clock can be deployed in various transportation vehicles,including aviation,aerospace,maritime,and land-based vehicles;provides remote time standards for geophysical monitoring and distributed coherent sensing;and promotes the unmanned and lightweight development of global time network synchronization.However,the current transportable version of laboratory optical clocks is still limited by factors such as environmental sensitivity,manual maintenance requirements,and high cost.Here we report a single-person portable optical frequency standard using the recently proposed atomic-filter-based laser“Voigt laser”as the local oscillator.It is worth mentioning that due to the inherent characteristics of Voigt lasers,the Voigt optical frequency standard can maintain turn-key functionality under harsh environmental impacts without any manual maintenance requirement.In our experiment,conducted over a duration of 12 min,we subjected the laser diode to multiple temperature shocks,resulting in a cumulative temperature fluctuation of 15℃.Following each temperature shock event,the Voigt optical frequency standard automatically relocked and restored the frequency output.Therefore,this demonstration marks a significant technological breakthrough in automatic quantum devices and might herald the arrival of fully automated time network systems.展开更多
The State Key Laboratory of Transient OpticsTechnology is attached to the Xi’an Institute ofOptics and Precision Mechanics of the CAS. The Laboratory is devoted to study of the theory and technology of transient opti...The State Key Laboratory of Transient OpticsTechnology is attached to the Xi’an Institute ofOptics and Precision Mechanics of the CAS. The Laboratory is devoted to study of the theory and technology of transient optics. Its research fields include concepts and technologies of ultrashort pulse generation, amplification, compression and measurement, ultrafast processes of interaction between light and matter, development, and application of measurement equipment of transient optics for scientific research and production. At present, its research activities are the following:展开更多
The paper describes our recent progress on key technologies and components for realizing optical packet switching, including an out-of-band optical label switching technique, an optical packet synchronizer and a burst...The paper describes our recent progress on key technologies and components for realizing optical packet switching, including an out-of-band optical label switching technique, an optical packet synchronizer and a burst-mode optical receiver.展开更多
We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD ...We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations.展开更多
Vertical-cavity surface-emitting lasers(VCSELs)are essential in modern optoelectronic systems,driving applications in high-speed optical communications,3D sensing,and LiDAR.While significant progress has been made in ...Vertical-cavity surface-emitting lasers(VCSELs)are essential in modern optoelectronic systems,driving applications in high-speed optical communications,3D sensing,and LiDAR.While significant progress has been made in improving VCSEL performance,the role of cavity geometry in optimizing key optical characteristics remains insufficiently explored.This study systematically examines how distinct cavity geometries—circular,square,D-shaped,mushroom-shaped,and pentagonal—affect both the static and dynamic properties of broad-area VCSELs.We analyze their effects on optical power,multimode behavior,beam profile,spatial coherence,and polarization dynamics.Our results show that breaking the continuous rotational symmetry of the cavity effectively increases gain utilization and power,changes the multimode lasing characteristics,shapes the beam,and modifies the polarization.Notably,the pentagonal VCSEL exhibits more than twice the optical power density of its circular counterpart.It also supports the highest number of modes and the fastest mode dynamics,driven by strong mode interaction.These properties make it a strong candidate for high-speed entropy generation.Mushroom-shaped VCSELs demonstrate high power and low spatial coherence,making them ideal for speckle-free imaging and illumination applications.Meanwhile,D-shaped VCSELs provide the most stable polarization and controllable multimode behavior with high power,showcasing their potential for applications that require stable and low-coherence light sources.This study offers a comprehensive analysis of the impact of cavity geometry on VCSEL performance,which provides insights for optimizing VCSEL designs tailored to diverse applications that require distinct properties with broad applicability to advanced imaging,sensing,optical coherence tomography,high-speed communication,and other photonic technologies.展开更多
基金the National Key R&D Program of China under Grants No.2017YFA0303704 and No.2018YFB2200400Natural Science Foundation of Beijing under Grant No.Z180012National Natural Science Foundation of China under Grants No.61875101 and No.91750206.
文摘Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61379153 and 61572529)
文摘We show that the secret key generation rate can be balanced with the maximum secure distance of four-state continuous-variable quantum key distribution（CV-QKD） by using the linear optics cloning machine（LOCM）. Benefiting from the LOCM operation, the LOCM-tuned noise can be employed by the reference partner of reconciliation to achieve higher secret key generation rates over a long distance. Simulation results show that the LOCM operation can flexibly regulate the secret key generation rate and the maximum secure distance and improve the performance of four-state CV-QKD protocol by dynamically tuning parameters in an appropriate range.
基金Innovation Program for Quantum Science and Technology(2021ZD0303200)National Natural Science Foundation of China(62405007,624B2010)+1 种基金China Postdoctoral Science Foundation(BX2021020)Wenzhou Major Science and Technology Innovation Key Project(ZG2020046)。
文摘The transportable optical clock can be deployed in various transportation vehicles,including aviation,aerospace,maritime,and land-based vehicles;provides remote time standards for geophysical monitoring and distributed coherent sensing;and promotes the unmanned and lightweight development of global time network synchronization.However,the current transportable version of laboratory optical clocks is still limited by factors such as environmental sensitivity,manual maintenance requirements,and high cost.Here we report a single-person portable optical frequency standard using the recently proposed atomic-filter-based laser“Voigt laser”as the local oscillator.It is worth mentioning that due to the inherent characteristics of Voigt lasers,the Voigt optical frequency standard can maintain turn-key functionality under harsh environmental impacts without any manual maintenance requirement.In our experiment,conducted over a duration of 12 min,we subjected the laser diode to multiple temperature shocks,resulting in a cumulative temperature fluctuation of 15℃.Following each temperature shock event,the Voigt optical frequency standard automatically relocked and restored the frequency output.Therefore,this demonstration marks a significant technological breakthrough in automatic quantum devices and might herald the arrival of fully automated time network systems.
文摘The State Key Laboratory of Transient OpticsTechnology is attached to the Xi’an Institute ofOptics and Precision Mechanics of the CAS. The Laboratory is devoted to study of the theory and technology of transient optics. Its research fields include concepts and technologies of ultrashort pulse generation, amplification, compression and measurement, ultrafast processes of interaction between light and matter, development, and application of measurement equipment of transient optics for scientific research and production. At present, its research activities are the following:
文摘The paper describes our recent progress on key technologies and components for realizing optical packet switching, including an out-of-band optical label switching technique, an optical packet synchronizer and a burst-mode optical receiver.
基金was supported by the ICT R&D programs of Ministry of Science, ICT and Future Planning/Institute for Information & Communications Technology Promotion (Grant No. B0101-16-1355)the Korea Institute of Science and Technology research program (Grant No. 2E27231)Korea Institute of Science and Technology-Electronics And Telecommunications Research Institute research program (Grant No. 2V05340)
文摘We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations.
基金supported by the King Abdullah University of Science and Technology(KAUST)under the Grant of Transition Award in Semiconductors:Grant No.FCC/1/5939the KAUST Center of Excellence for Renewable Energy and Storage Technologies(CREST):Grant No.FCC/1/5937the KAUST Grant Nos.RFS-OFP2023-5534,BAS/1/1614-01-01,ORA-2022-5313,and ORFS-2022-CRG11-5079.
文摘Vertical-cavity surface-emitting lasers(VCSELs)are essential in modern optoelectronic systems,driving applications in high-speed optical communications,3D sensing,and LiDAR.While significant progress has been made in improving VCSEL performance,the role of cavity geometry in optimizing key optical characteristics remains insufficiently explored.This study systematically examines how distinct cavity geometries—circular,square,D-shaped,mushroom-shaped,and pentagonal—affect both the static and dynamic properties of broad-area VCSELs.We analyze their effects on optical power,multimode behavior,beam profile,spatial coherence,and polarization dynamics.Our results show that breaking the continuous rotational symmetry of the cavity effectively increases gain utilization and power,changes the multimode lasing characteristics,shapes the beam,and modifies the polarization.Notably,the pentagonal VCSEL exhibits more than twice the optical power density of its circular counterpart.It also supports the highest number of modes and the fastest mode dynamics,driven by strong mode interaction.These properties make it a strong candidate for high-speed entropy generation.Mushroom-shaped VCSELs demonstrate high power and low spatial coherence,making them ideal for speckle-free imaging and illumination applications.Meanwhile,D-shaped VCSELs provide the most stable polarization and controllable multimode behavior with high power,showcasing their potential for applications that require stable and low-coherence light sources.This study offers a comprehensive analysis of the impact of cavity geometry on VCSEL performance,which provides insights for optimizing VCSEL designs tailored to diverse applications that require distinct properties with broad applicability to advanced imaging,sensing,optical coherence tomography,high-speed communication,and other photonic technologies.
