Recently, the Hong-Ou-Mandel （HOM） interference between two independent weak coherent pulses （WCPs） has been paid much attention due to the measurement-device-independent （MDI） quantum key distribution （QKD）. ...Recently, the Hong-Ou-Mandel （HOM） interference between two independent weak coherent pulses （WCPs） has been paid much attention due to the measurement-device-independent （MDI） quantum key distribution （QKD）. Using classical wave theory, articles reported before show that the visibility of this kind of HOM-type interference is 〈 50%. In this work, we analyze this kind of interference using quantum optics, which reveals more details compared to the wave theory. Analyses confirm the maximum visibility of 50%. And we conclude that the maximum visibility of 50% comes from the two single-photon states in WCPs, without considering the noise. In the experiment, we successfully approach the visibility of 50% by using WCPs splitting from the single pico-second laser source and phase scanning. Since this kind of HOM interference is immune to slow phase fluctuations, both the realized and proposed experiment designs can provide stable ways of high-resolution optical distance detection.展开更多
We present a two-photon interference experiment in a modified Mach-Zehnder （MZ） interferometer in which two Hong-Ou-Mandel effects occur in tandem and construct superposed two-photon states. The signal photons pass ...We present a two-photon interference experiment in a modified Mach-Zehnder （MZ） interferometer in which two Hong-Ou-Mandel effects occur in tandem and construct superposed two-photon states. The signal photons pass both the arms of the MZ interferometer while the idler photons pass one arm only. Interestingly, the probability of the idler photons emerging from any output port still shows a sine oscillation with the two-photon phase difference and it can be characterized only by the indistinguishability of the two-photon amplitudes. We also observe a two-photon interference pattern with a period being equal to the wavelength of the parametric photons instead of the two-photon photonie de Broglie wavelength due to the presence of two-photon phase difference, in particular, with complementary probabilities of finding the two-photon pairs in two output ports. The abundant observations can facilitate a more comprehensive understanding of the two-photon interference.展开更多
The second-order interference of two independent photons with different spectra in a Shih-Alley/Hong-Ou-Mandel interferometer is studied in Feynman's path integral theory. There is a second-order interference patt...The second-order interference of two independent photons with different spectra in a Shih-Alley/Hong-Ou-Mandel interferometer is studied in Feynman's path integral theory. There is a second-order interference pattern for photons with different spectra if the photons are indistinguishable for the employed detection system. The conditions to observe the second-order temporal beating with photons of different spectra are analyzed. The influence of the response time of the detection system on the observed second-order interference pattern is also discussed. It is a direct result of that measurement in quantum mechanics is dependent on the employed measuring apparatus. The results are helpful to understand the physics of two-photon interference in different schemes.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
基金Project supported by the National Basic Research Program of China(Grants Nos.2011CBA00200 and 2011CB921200)the National Natural Science Foundation of China(Grant Nos.61201239,61205118,11304397,and 61475148)the“Strategic Priority Research Program(B)”of the Chinese Academy of Sciences(Grant No.XDB01030100 and XDB01030300)
文摘Recently, the Hong-Ou-Mandel （HOM） interference between two independent weak coherent pulses （WCPs） has been paid much attention due to the measurement-device-independent （MDI） quantum key distribution （QKD）. Using classical wave theory, articles reported before show that the visibility of this kind of HOM-type interference is 〈 50%. In this work, we analyze this kind of interference using quantum optics, which reveals more details compared to the wave theory. Analyses confirm the maximum visibility of 50%. And we conclude that the maximum visibility of 50% comes from the two single-photon states in WCPs, without considering the noise. In the experiment, we successfully approach the visibility of 50% by using WCPs splitting from the single pico-second laser source and phase scanning. Since this kind of HOM interference is immune to slow phase fluctuations, both the realized and proposed experiment designs can provide stable ways of high-resolution optical distance detection.
基金Supported by the National Key R&D Program of China under Grant Nos 2017YFA0303800 and 2017YFA0303700the National Natural Science Foundation of China under Grant Nos 11534006,11774183 and 11674184+1 种基金the Natural Science Foundation of Tianjin under Grant No 16JCZDJC31300the Collaborative Innovation Center of Extreme Optics
文摘We present a two-photon interference experiment in a modified Mach-Zehnder （MZ） interferometer in which two Hong-Ou-Mandel effects occur in tandem and construct superposed two-photon states. The signal photons pass both the arms of the MZ interferometer while the idler photons pass one arm only. Interestingly, the probability of the idler photons emerging from any output port still shows a sine oscillation with the two-photon phase difference and it can be characterized only by the indistinguishability of the two-photon amplitudes. We also observe a two-photon interference pattern with a period being equal to the wavelength of the parametric photons instead of the two-photon photonie de Broglie wavelength due to the presence of two-photon phase difference, in particular, with complementary probabilities of finding the two-photon pairs in two output ports. The abundant observations can facilitate a more comprehensive understanding of the two-photon interference.
基金Project supported by the Key Research and Development Project of Shaanxi Province,China(Grant No.2019ZDLGY09-08)the Open Fund of MOE Key Laboratory of Weak-Light Nonlinear Photonics,China(Grant No.OS19-2)the Fundamental Research Funds for the Central Universities,China
文摘The second-order interference of two independent photons with different spectra in a Shih-Alley/Hong-Ou-Mandel interferometer is studied in Feynman's path integral theory. There is a second-order interference pattern for photons with different spectra if the photons are indistinguishable for the employed detection system. The conditions to observe the second-order temporal beating with photons of different spectra are analyzed. The influence of the response time of the detection system on the observed second-order interference pattern is also discussed. It is a direct result of that measurement in quantum mechanics is dependent on the employed measuring apparatus. The results are helpful to understand the physics of two-photon interference in different schemes.
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.
