The quantum entangled photon-pair source,as an essential component of optical quantum systems,holds great potential for applications such as quantum teleportation,quan-tum computing,and quantum imaging.The current wor...The quantum entangled photon-pair source,as an essential component of optical quantum systems,holds great potential for applications such as quantum teleportation,quan-tum computing,and quantum imaging.The current workhorse technique for preparing photon pairs involves performing spon-taneous parametric down conversion(SPDC)in bulk nonlinear crystals.However,the current power consumption and cost of preparing entangled photon-pair sources are relatively high,pos-ing challenges to their integration and scalability.In this paper,we propose a low-power system model for the quantum entan-gled photon-pair source based on SPDC theory and phase matching technology.This model allows us to analyze the per-formance of each module and the influence of component cha-racteristics on the overall system.In our experimental setup,we utilize a 5 mW laser diode and a typical type-II barium metabo-rate(BBO)crystal to prepare an entangled photon-pair source.The experimental results are in excellent agreement with the model,indicating a significant step towards achieving the goal of low-power and low-cost entangled photon-pair sources.This achievement not only contributes to the practical application of quantum entanglement lighting,but also paves the way for the widespread adoption of optical quantum systems in the future.展开更多
We propose a novel optical method for glucose measurement based on difuse photon-pair density wave(DPPDW)in a multiple scattering medium(MSM)where the light scattering of photon-pair is induced by refractive index mis...We propose a novel optical method for glucose measurement based on difuse photon-pair density wave(DPPDW)in a multiple scattering medium(MSM)where the light scattering of photon-pair is induced by refractive index mismatch between scatters and phantom solution.Experi-mentally,the DPPDW propagates in MSM via a two frequency laser(TFL)beam wherein highly correlated pairs of linear polarized photons are generated.The reduced scattering coefficientμ2s and absorption coefficientμ2a of DPPDW are measured simultaneously in terms of the amplitude and phase measurements of the detected heterodyne signal under arrangement at different dis-tances between the source and detection fibers in MSM.The results show that the sensitivity of glucose detection via glucose-induced change of reduced scattering coefficient(δμ′2)is 0.049%mM^(-1)in a 1%intralipid solution.In addition,the linear range ofδμ′2s vs glucose concentration implies that this DPPDW method can be used to monitor glucose concentration continuously and noninvasively subcutaneously.展开更多
To achieve photon-pair generation scaling, we optimize the quality factor of microring resonators for efficient continuous-wave-pumped spontaneous four-wave mixing. Numerical studies indicate that a high intrinsic qua...To achieve photon-pair generation scaling, we optimize the quality factor of microring resonators for efficient continuous-wave-pumped spontaneous four-wave mixing. Numerical studies indicate that a high intrinsic quality factor makes high pair rate and pair brightness possible, in which the maximums take place under overcoupling and critical-coupling conditions, respectively. We fabricate six all-pass-type microring resonator samples on a silicon-on-insulator chip involving gap width as the only degree of freedom. The signal count rate, pair brightness,and coincidence rate of all the samples are characterized, which are then compared with the modified simulations by taking the detector saturation and nonlinear loss into account. Being experimentally validated for the first time to the best of our knowledge, this work explicitly demonstrates that reducing the round-trip loss in a ring cavity and designing the corresponding optimized gap width are more effective to generate high-rate or high-brightness photon pairs than the conventional strategy of simply increasing the quality factor.展开更多
对星地量子测距过程中利用捕获跟踪瞄准(Acquisition tracking and pointing,ATP)系统进行纠缠光子对收发和利用符合计数原理计算纠缠光子对到达时间差(Time difference of arrival,TDOA)的两个关键过程进行了仿真实验研究。根据"...对星地量子测距过程中利用捕获跟踪瞄准(Acquisition tracking and pointing,ATP)系统进行纠缠光子对收发和利用符合计数原理计算纠缠光子对到达时间差(Time difference of arrival,TDOA)的两个关键过程进行了仿真实验研究。根据"墨子号"量子卫星真实的6个轨道参数,对卫星的运动轨迹以及地面用户对从卫星上发射到地面信号的ATP过程进行系统仿真实验研究。分析并设计了ATP系统的结构;借助于Simulink环境下的仿真软件,建立ATP时域仿真系统,将所计算出的"墨子号"方位角与俯仰角位置信号作为ATP系统的输入信号,对所建立的ATP系统进行星地纠缠光收发的捕获跟踪瞄准过程进行了系统仿真实验,跟踪精度达到了2μrad;在实现地面用户对量子卫星的精确跟踪的基础上,设计并进行纠缠光子对收发及其符合计数的仿真实验;拟合出纠缠光子对皮秒级误差的到达时间差,实现了精确的量子测距过程,为量子导航系统的实现提供了一定的理论及仿真实验基础。展开更多
文摘The quantum entangled photon-pair source,as an essential component of optical quantum systems,holds great potential for applications such as quantum teleportation,quan-tum computing,and quantum imaging.The current workhorse technique for preparing photon pairs involves performing spon-taneous parametric down conversion(SPDC)in bulk nonlinear crystals.However,the current power consumption and cost of preparing entangled photon-pair sources are relatively high,pos-ing challenges to their integration and scalability.In this paper,we propose a low-power system model for the quantum entan-gled photon-pair source based on SPDC theory and phase matching technology.This model allows us to analyze the per-formance of each module and the influence of component cha-racteristics on the overall system.In our experimental setup,we utilize a 5 mW laser diode and a typical type-II barium metabo-rate(BBO)crystal to prepare an entangled photon-pair source.The experimental results are in excellent agreement with the model,indicating a significant step towards achieving the goal of low-power and low-cost entangled photon-pair sources.This achievement not only contributes to the practical application of quantum entanglement lighting,but also paves the way for the widespread adoption of optical quantum systems in the future.
文摘We propose a novel optical method for glucose measurement based on difuse photon-pair density wave(DPPDW)in a multiple scattering medium(MSM)where the light scattering of photon-pair is induced by refractive index mismatch between scatters and phantom solution.Experi-mentally,the DPPDW propagates in MSM via a two frequency laser(TFL)beam wherein highly correlated pairs of linear polarized photons are generated.The reduced scattering coefficientμ2s and absorption coefficientμ2a of DPPDW are measured simultaneously in terms of the amplitude and phase measurements of the detected heterodyne signal under arrangement at different dis-tances between the source and detection fibers in MSM.The results show that the sensitivity of glucose detection via glucose-induced change of reduced scattering coefficient(δμ′2)is 0.049%mM^(-1)in a 1%intralipid solution.In addition,the linear range ofδμ′2s vs glucose concentration implies that this DPPDW method can be used to monitor glucose concentration continuously and noninvasively subcutaneously.
基金National Natural Science Foundation of China(NSFC)(60907003)Natural Science Foundation of Hunan Province,China(13JJ3001)+2 种基金Program for New Century Excellent Talents in University(NCET),China(NCET-12-0142)Danmarks Grundforskningsfond(DNRF)(DNRF123)China Scholarship Council(CSC)
文摘To achieve photon-pair generation scaling, we optimize the quality factor of microring resonators for efficient continuous-wave-pumped spontaneous four-wave mixing. Numerical studies indicate that a high intrinsic quality factor makes high pair rate and pair brightness possible, in which the maximums take place under overcoupling and critical-coupling conditions, respectively. We fabricate six all-pass-type microring resonator samples on a silicon-on-insulator chip involving gap width as the only degree of freedom. The signal count rate, pair brightness,and coincidence rate of all the samples are characterized, which are then compared with the modified simulations by taking the detector saturation and nonlinear loss into account. Being experimentally validated for the first time to the best of our knowledge, this work explicitly demonstrates that reducing the round-trip loss in a ring cavity and designing the corresponding optimized gap width are more effective to generate high-rate or high-brightness photon pairs than the conventional strategy of simply increasing the quality factor.
文摘对星地量子测距过程中利用捕获跟踪瞄准(Acquisition tracking and pointing,ATP)系统进行纠缠光子对收发和利用符合计数原理计算纠缠光子对到达时间差(Time difference of arrival,TDOA)的两个关键过程进行了仿真实验研究。根据"墨子号"量子卫星真实的6个轨道参数,对卫星的运动轨迹以及地面用户对从卫星上发射到地面信号的ATP过程进行系统仿真实验研究。分析并设计了ATP系统的结构;借助于Simulink环境下的仿真软件,建立ATP时域仿真系统,将所计算出的"墨子号"方位角与俯仰角位置信号作为ATP系统的输入信号,对所建立的ATP系统进行星地纠缠光收发的捕获跟踪瞄准过程进行了系统仿真实验,跟踪精度达到了2μrad;在实现地面用户对量子卫星的精确跟踪的基础上,设计并进行纠缠光子对收发及其符合计数的仿真实验;拟合出纠缠光子对皮秒级误差的到达时间差,实现了精确的量子测距过程,为量子导航系统的实现提供了一定的理论及仿真实验基础。
