We study the photon statistics of pulse-pumped four-wave mixing in fibers with weak coherent signal injection by measuring the intensity correlation functions of individual signal and idler fields. The experimental re...We study the photon statistics of pulse-pumped four-wave mixing in fibers with weak coherent signal injection by measuring the intensity correlation functions of individual signal and idler fields. The experimental results show that the intensity correlation function of individual signal(idler) field g_(s(i))^(2) decreases with the intensity of signal injection. After applying narrow band filter in signal(idler) band, the value of g_(s(i))^(2) decreases from 1.9 ± 0.02(1.9 ± 0.02) to 1.03 ± 0.02(1.05 ± 0.02) when the intensity of signal injection varies from 0 to 120 photons/pulse. The results indicate that the photon statistics changes from Bose–Einstein distribution to Poisson distribution. We calculate the intensity correlation functions by using the multi-mode theory of four-wave mixing in fibers. The theoretical curves well fit the experimental results.Our investigation will be useful for mitigating the crosstalk between quantum and classical channels in a dense wavelength division multiplexing network.展开更多
We extend a previous model of the author which generalizes Bell local hidden variable models to the case of entangled photon pairs assuming that the standard Bell correlation functions depend on a hidden vacuum index....We extend a previous model of the author which generalizes Bell local hidden variable models to the case of entangled photon pairs assuming that the standard Bell correlation functions depend on a hidden vacuum index. We deduce a generalization of Bell theorem assuming that classical observables are not dichotomic and that photon pair emission and detection is not a stationary stochastic process. We derive a photon imperfect polarization correlation functions due to rotational invariance breaking induced by hidden vacuum spin currents. We implement formally this approach deducing a generalization of C.H.S.H. inequalities which asymptotically converges to the standard one and which might be competitive with standard quantum mechanics predictions. We suggest to test this inequalities conceiving new E.P.R.-Bell like tests with time dependent detector efficiency and photon flux. Finally, we suggest to apply these generalized inequalities to the correlation functions of entangled classical spinning waves realized recently with metamaterials.展开更多
The characterization of complexes is particularly critical for quality control and development of gene delivery systems. Here, the method of capillary zone electrophoresis (CZE) for the characterization of DNA and p...The characterization of complexes is particularly critical for quality control and development of gene delivery systems. Here, the method of capillary zone electrophoresis (CZE) for the characterization of DNA and polyoL-lysine (MW 28 500) or DNA and poly-L-lysine modified with polyethylene glycol (MW10 000) complexes at various charge ratios in phosphate buffer is described firstly. During the characterization, DNA complexes can be separated into various components with different charge-to-mass ratio, i.e, components with single physicochemical property. And also the size and zeta potential of complexes were characterized by using photon correlation spectroscopy. This method is useful to characterize various complexes formed by DNA and polycations, and has the potential to separate complexes into homogeneous component for better transfection efficiency in vitro and in vivo in future.展开更多
We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter(PFDM).Considering the cosmological constant as the positive pressure of the system and volume as its...We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter(PFDM).Considering the cosmological constant as the positive pressure of the system and volume as its conjugate variable,we analyze the thermodynamics of our black holes in the extended phase space.Owing to the background clouds of strings parameter(a)and the parameter endowed with PFDM(β),we analyze the Hawking temperature,entropy,and specific heat.Furthermore,we investigate the relationship between the photon sphere radius and phase transition for the Letelier AdS black holes immersed in PFDM.Through the analysis,with a particular condition,non-monotonic behaviors are found between the photon sphere radius,impact parameter,PFDM parameter,temperature,and pressure.We can regard the changes in both the photon sphere radius and impact parameter before and after phase transition as the order parameter;their critical exponents near the critical point are equal to the same value,1/2,similar to that in ordinary thermal systems.This indicates that a universal relation of gravity may exist near the critical point for a black hole thermodynamic system.展开更多
Objective To explore the correlation between quantitative value of joint bone scan by single photon emission computed tomography(SPECT)and serum bone metabolic markers in patients with active rheumatoid arthritis(RA)....Objective To explore the correlation between quantitative value of joint bone scan by single photon emission computed tomography(SPECT)and serum bone metabolic markers in patients with active rheumatoid arthritis(RA).Methods Clinical data of 60 newly diagnosed RA patients were retrospectively collected in Department展开更多
In t.his contribution, we briefly recall the basic concepts of quantum optics and properties of semicon- ductor quantum clot. (QD) which a.re necessary to the nnderstanding of the physics of single-photon generation...In t.his contribution, we briefly recall the basic concepts of quantum optics and properties of semicon- ductor quantum clot. (QD) which a.re necessary to the nnderstanding of the physics of single-photon generation with single QDs. Firstly, we address the theory of quantmn emitter-cavity system, the fluorescence and optical properties of semiconductor QDs, and the photon statistics as well as opti- cal properties of the QDs. We then review the localizatioll of single semiconductor QDs in quantum confined optical microcavity systems to achieve their overall optical properties and perfornances in terms of strong coupling regime, elfieiency, directionality, and polarization control. Furthermore, we will discuss the recenl, progress on the fabrication of single photon sources, and various a.pproaehes for embedding single QDs into mieroca,vities or photonic crystal nanoeavities and show how to ex- tend the wavelength range. We focus in part;icular on new generations of electrically driven QD single photon source leading to high repetition rates, efficiencies at elevated temperature operation. Besides strong eoupling regime, and high collection new development;s of room temperature sin- gle photon emission in the strong coupling regime are reviewed. The generation of indistinguishable photons and remaining challenges for pract ical single-photon sources are also discussed.展开更多
In this letter, the technique of laser self-mixing effect is employed for nano-particle size analysis. In contrast to the photon correlation spectroscopy (PCS) and photon cross correlation spectroscopy (PCCS), the...In this letter, the technique of laser self-mixing effect is employed for nano-particle size analysis. In contrast to the photon correlation spectroscopy (PCS) and photon cross correlation spectroscopy (PCCS), the main advantages of this technique are sensitive, compact, low-cost, and simple experimental setup etc. An improved Kaczmarz projection method is developed in the inversion problem to extract the particle size distribution. The experimental results prove that nano-particle size can be measured reasonably by using the self-mixing effect technique combined with the improved projection algorithm.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11527808)the State Key Development Program for Basic Research of China(Grant No.2014CB340103)+3 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120032110055)the Natural Science Foundation of Tianjin,China(Grant No.14JCQNJC02300)the Program for Changjiang Scholars and Innovative Research Team in University,Chinathe Program of Introducing Talents of Discipline to Universities,China(Grant No.B07014)
文摘We study the photon statistics of pulse-pumped four-wave mixing in fibers with weak coherent signal injection by measuring the intensity correlation functions of individual signal and idler fields. The experimental results show that the intensity correlation function of individual signal(idler) field g_(s(i))^(2) decreases with the intensity of signal injection. After applying narrow band filter in signal(idler) band, the value of g_(s(i))^(2) decreases from 1.9 ± 0.02(1.9 ± 0.02) to 1.03 ± 0.02(1.05 ± 0.02) when the intensity of signal injection varies from 0 to 120 photons/pulse. The results indicate that the photon statistics changes from Bose–Einstein distribution to Poisson distribution. We calculate the intensity correlation functions by using the multi-mode theory of four-wave mixing in fibers. The theoretical curves well fit the experimental results.Our investigation will be useful for mitigating the crosstalk between quantum and classical channels in a dense wavelength division multiplexing network.
文摘We extend a previous model of the author which generalizes Bell local hidden variable models to the case of entangled photon pairs assuming that the standard Bell correlation functions depend on a hidden vacuum index. We deduce a generalization of Bell theorem assuming that classical observables are not dichotomic and that photon pair emission and detection is not a stationary stochastic process. We derive a photon imperfect polarization correlation functions due to rotational invariance breaking induced by hidden vacuum spin currents. We implement formally this approach deducing a generalization of C.H.S.H. inequalities which asymptotically converges to the standard one and which might be competitive with standard quantum mechanics predictions. We suggest to test this inequalities conceiving new E.P.R.-Bell like tests with time dependent detector efficiency and photon flux. Finally, we suggest to apply these generalized inequalities to the correlation functions of entangled classical spinning waves realized recently with metamaterials.
文摘The characterization of complexes is particularly critical for quality control and development of gene delivery systems. Here, the method of capillary zone electrophoresis (CZE) for the characterization of DNA and polyoL-lysine (MW 28 500) or DNA and poly-L-lysine modified with polyethylene glycol (MW10 000) complexes at various charge ratios in phosphate buffer is described firstly. During the characterization, DNA complexes can be separated into various components with different charge-to-mass ratio, i.e, components with single physicochemical property. And also the size and zeta potential of complexes were characterized by using photon correlation spectroscopy. This method is useful to characterize various complexes formed by DNA and polycations, and has the potential to separate complexes into homogeneous component for better transfection efficiency in vitro and in vivo in future.
基金Supported by the National Natural Science Foundation of China(11875151,12347177,12247101)the 111 Project under(B20063)the Lanzhou City's Scientific Research Funding Subsidy to Lanzhou University。
文摘We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter(PFDM).Considering the cosmological constant as the positive pressure of the system and volume as its conjugate variable,we analyze the thermodynamics of our black holes in the extended phase space.Owing to the background clouds of strings parameter(a)and the parameter endowed with PFDM(β),we analyze the Hawking temperature,entropy,and specific heat.Furthermore,we investigate the relationship between the photon sphere radius and phase transition for the Letelier AdS black holes immersed in PFDM.Through the analysis,with a particular condition,non-monotonic behaviors are found between the photon sphere radius,impact parameter,PFDM parameter,temperature,and pressure.We can regard the changes in both the photon sphere radius and impact parameter before and after phase transition as the order parameter;their critical exponents near the critical point are equal to the same value,1/2,similar to that in ordinary thermal systems.This indicates that a universal relation of gravity may exist near the critical point for a black hole thermodynamic system.
文摘Objective To explore the correlation between quantitative value of joint bone scan by single photon emission computed tomography(SPECT)and serum bone metabolic markers in patients with active rheumatoid arthritis(RA).Methods Clinical data of 60 newly diagnosed RA patients were retrospectively collected in Department
基金G. Shan would like to thank Prof. C. Cohen-Tannoudji (Nobel Laureate in 1997) for his fruitful discus- sion on quantum optics and particularly theory of quantum-dot- cavity during his visit at City University of Hong Kong in 2012. This work was partially sponsored by General Research Grant Project No. CityU 119212 from RGC, Hong Kong, and the re- search activity fund from CityU to support research work as a visiting scholar at Columbia University. W. Huang acknowledges the support from the National Basic Research Program of China (973 Program, Grant No. 2009CB930601). Z. Yin acknowledges the support by the National Basic Research Program of China (973 Program, Grant Nos. 2011CBA00300 and 2011CBA00302), and the National Natural Science Foundation of China (Grant Nos. 61033001 and 11105136).
文摘In t.his contribution, we briefly recall the basic concepts of quantum optics and properties of semicon- ductor quantum clot. (QD) which a.re necessary to the nnderstanding of the physics of single-photon generation with single QDs. Firstly, we address the theory of quantmn emitter-cavity system, the fluorescence and optical properties of semiconductor QDs, and the photon statistics as well as opti- cal properties of the QDs. We then review the localizatioll of single semiconductor QDs in quantum confined optical microcavity systems to achieve their overall optical properties and perfornances in terms of strong coupling regime, elfieiency, directionality, and polarization control. Furthermore, we will discuss the recenl, progress on the fabrication of single photon sources, and various a.pproaehes for embedding single QDs into mieroca,vities or photonic crystal nanoeavities and show how to ex- tend the wavelength range. We focus in part;icular on new generations of electrically driven QD single photon source leading to high repetition rates, efficiencies at elevated temperature operation. Besides strong eoupling regime, and high collection new development;s of room temperature sin- gle photon emission in the strong coupling regime are reviewed. The generation of indistinguishable photons and remaining challenges for pract ical single-photon sources are also discussed.
基金supported by the Nano-Project of Shanghai Science and Technology Commission under Grant No.0452nm029.
文摘In this letter, the technique of laser self-mixing effect is employed for nano-particle size analysis. In contrast to the photon correlation spectroscopy (PCS) and photon cross correlation spectroscopy (PCCS), the main advantages of this technique are sensitive, compact, low-cost, and simple experimental setup etc. An improved Kaczmarz projection method is developed in the inversion problem to extract the particle size distribution. The experimental results prove that nano-particle size can be measured reasonably by using the self-mixing effect technique combined with the improved projection algorithm.