We propose a new type of dispersion flattening technology, which can generate an ultra-flat group velocity dispersion profile with five and six zero-dispersion wavelengths(ZDWs). The dispersion value varies from-0.15 ...We propose a new type of dispersion flattening technology, which can generate an ultra-flat group velocity dispersion profile with five and six zero-dispersion wavelengths(ZDWs). The dispersion value varies from-0.15 to 0.35 ps/(nm·km) from 4 to 8 μm, which to the best of our knowledge is the flattest one reported so far, and the dispersion flatness is improved by more than an order of magnitude. We explain the principle of producing six ZDWs. Mode distribution in this waveguide is made stable over a wide bandwidth. General guidelines to systematically control the dispersion value, sign, and slope are provided, and one can achieve the desired dispersion by properly adjusting the structural parameters. Fabrication tolerance of this waveguide is also examined.展开更多
A single-end adaptive-optics(AO)module is experimentally demonstrated to mitigate the emulated atmospheric turbulence efects in a bi-directional quantum communication link,which employs orbital angular momentum(OAM)fo...A single-end adaptive-optics(AO)module is experimentally demonstrated to mitigate the emulated atmospheric turbulence efects in a bi-directional quantum communication link,which employs orbital angular momentum(OAM)for data encoding.A classical Gaussian beam is used as a probe to detect the turbulence-induced wavefront distortion in the forward direction of the link.Based on the detected wavefront distortion,an AO system located on one end of the link is used to simultaneously compensate for the forward and backward channels.Specifcally,with emulated turbulence and when the probe is turned on,the mode purity of photons carrying OAMℓ=1 is improved by∼21%with AO mitigation.We also measured the performance when encoding data using OAM{ℓ=−1,+2}and{ℓ=−2,+1}in the forward and backward channels,respectively,at 10 Mbit/s per channel with one photon per pulse on average.For this case,we found that the AO system could reduce the turbulence efects increased quantum-symbolerror-rate(QSER)by∼76%and∼74%,for both channels in the uni-directional and bi-directional cases,respectively.Similar QSER improvement is observed for the opposite direction channels in the bi-directional case.展开更多
基金National Natural Science Foundation of China(61775164,61225005,61775165)
文摘We propose a new type of dispersion flattening technology, which can generate an ultra-flat group velocity dispersion profile with five and six zero-dispersion wavelengths(ZDWs). The dispersion value varies from-0.15 to 0.35 ps/(nm·km) from 4 to 8 μm, which to the best of our knowledge is the flattest one reported so far, and the dispersion flatness is improved by more than an order of magnitude. We explain the principle of producing six ZDWs. Mode distribution in this waveguide is made stable over a wide bandwidth. General guidelines to systematically control the dispersion value, sign, and slope are provided, and one can achieve the desired dispersion by properly adjusting the structural parameters. Fabrication tolerance of this waveguide is also examined.
基金This work is supported by the Ofce of Naval Research(ONR)[N00014-15-1-2635]the Vannevar Bush Faculty Fellowship program sponsored by the Basic Research Ofce of the Assistant Secretary of Defense for Research and Engineering and funded by ONR[N00014-16-1-2813]the National Science Foundation(NSF)[ECCS-1509965].
文摘A single-end adaptive-optics(AO)module is experimentally demonstrated to mitigate the emulated atmospheric turbulence efects in a bi-directional quantum communication link,which employs orbital angular momentum(OAM)for data encoding.A classical Gaussian beam is used as a probe to detect the turbulence-induced wavefront distortion in the forward direction of the link.Based on the detected wavefront distortion,an AO system located on one end of the link is used to simultaneously compensate for the forward and backward channels.Specifcally,with emulated turbulence and when the probe is turned on,the mode purity of photons carrying OAMℓ=1 is improved by∼21%with AO mitigation.We also measured the performance when encoding data using OAM{ℓ=−1,+2}and{ℓ=−2,+1}in the forward and backward channels,respectively,at 10 Mbit/s per channel with one photon per pulse on average.For this case,we found that the AO system could reduce the turbulence efects increased quantum-symbolerror-rate(QSER)by∼76%and∼74%,for both channels in the uni-directional and bi-directional cases,respectively.Similar QSER improvement is observed for the opposite direction channels in the bi-directional case.
