Abstract We use moderate deviations to study the signal detection problem for a diffusion model. We establish a moderate deviation principle for the log-likelihood function of the diffusion model. Then applying the mo...Abstract We use moderate deviations to study the signal detection problem for a diffusion model. We establish a moderate deviation principle for the log-likelihood function of the diffusion model. Then applying the moderate deviation estimates to hypothesis testing for signal detection problem we give a decision region such that its error probability of the second kind tends to zero with faster speed than the error probability of the first kind when the error probability of the first kind is approximated by e-ατ（T）, where α〉 0, τ（T） = o（T） and τ（T）→∞ as the observation time T goes to infinity.展开更多
Telecom-band polarization-entangled photon- pair source has been widely used in quantum communi- cation due to its acceptable transmission loss. It is also used in cooperation with wavelength-division multiplexing （...Telecom-band polarization-entangled photon- pair source has been widely used in quantum communi- cation due to its acceptable transmission loss. It is also used in cooperation with wavelength-division multiplexing （WDM） to construct entanglement distributor. However, previous schemes generally are not suitable for multinode scenario. In this paper, we construct a telecom-band po- larization-entangled photon-pair source, and it shows ul- trahigh fidelity and concurrence which are both greater than 90 % （raw data）. Moreover, we set up a four-by-four entanglement distributor based on WDM. We check the 16 Clauser-Horne-Shimony-Holt inequalities, which show nonlocality. Lastly, as an example of practical application of this source, we estimate the quantum bit error rates and quantum secret key rates when it is used in quantum key distribution. Furthermore, the transmission of entanglement in long optical fibers is also demonstrated.展开更多
By analyzing the principle of dual-pump parametric amplification and the polarization dependent gain of fiber optical parametric amplifier(FOPA),a polarization-insensitive FOPA based on polarization-diversity techniqu...By analyzing the principle of dual-pump parametric amplification and the polarization dependent gain of fiber optical parametric amplifier(FOPA),a polarization-insensitive FOPA based on polarization-diversity technique with dual parallel pumps is presented.The performances of polarization-insensitivity,gain and BER are theoretically analyzed and numerically simulated by comparing the proposed scheme with parallel pump solution and orthogonal pump solution.The presented solution can reduce the complexity of state of polarization(SoP) of pumps.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos.10871153 and 11171262)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 200804860048)
文摘Abstract We use moderate deviations to study the signal detection problem for a diffusion model. We establish a moderate deviation principle for the log-likelihood function of the diffusion model. Then applying the moderate deviation estimates to hypothesis testing for signal detection problem we give a decision region such that its error probability of the second kind tends to zero with faster speed than the error probability of the first kind when the error probability of the first kind is approximated by e-ατ（T）, where α〉 0, τ（T） = o（T） and τ（T）→∞ as the observation time T goes to infinity.
基金This work was supported by the National Nat- ural Science Foundation of China （61327901, 61490711, 11274289, 11325419, 11374288 and 11104261）, the National Basic Research Program of China （2011CB921200）, the Strategic Priority Research Program （B） of the Chinese Academy of Sciences （XDB01030300）, the National Science Ftmd for Distinguished Young Scholars （61225025）, and the Fundamental Research Funds for Central Universities （WK2470000011）.
文摘Telecom-band polarization-entangled photon- pair source has been widely used in quantum communi- cation due to its acceptable transmission loss. It is also used in cooperation with wavelength-division multiplexing （WDM） to construct entanglement distributor. However, previous schemes generally are not suitable for multinode scenario. In this paper, we construct a telecom-band po- larization-entangled photon-pair source, and it shows ul- trahigh fidelity and concurrence which are both greater than 90 % （raw data）. Moreover, we set up a four-by-four entanglement distributor based on WDM. We check the 16 Clauser-Horne-Shimony-Holt inequalities, which show nonlocality. Lastly, as an example of practical application of this source, we estimate the quantum bit error rates and quantum secret key rates when it is used in quantum key distribution. Furthermore, the transmission of entanglement in long optical fibers is also demonstrated.
基金supported by the National Basic Research Program of China (2010CB328304)
文摘By analyzing the principle of dual-pump parametric amplification and the polarization dependent gain of fiber optical parametric amplifier(FOPA),a polarization-insensitive FOPA based on polarization-diversity technique with dual parallel pumps is presented.The performances of polarization-insensitivity,gain and BER are theoretically analyzed and numerically simulated by comparing the proposed scheme with parallel pump solution and orthogonal pump solution.The presented solution can reduce the complexity of state of polarization(SoP) of pumps.
