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M Sutton - One of the best experts on this subject based on the ideXlab platform.
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a review of x ray Intensity Fluctuation spectroscopy
Comptes Rendus Physique, 2008Co-Authors: M SuttonAbstract:Abstract This article reviews the literature on X-ray Fluctuation Intensity spectroscopy or, as it is often called, X-ray photon correlation spectroscopy. It highlights measurements using different types of diffuse scattering. To cite this article: M. Sutton, C. R. Physique 9 (2008).
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x ray Intensity Fluctuation spectroscopy by heterodyne detection
Journal of Synchrotron Radiation, 2006Co-Authors: F Livet, F Bley, Francoise Ehrburgerdolle, Isabelle Morfin, E Geissler, M SuttonAbstract:A straightforward way of measuring X-ray Intensity Fluctuation spectroscopy in a small-angle X-ray scattering configuration is demonstrated using heterodyne techniques. Two examples are presented: the Brownian motion of latex spheres in glycerol, and a Doppler velocity experiment demonstrating the motion and the relaxation of carbon-black-filled elastomers after uniaxial stretching. In the latter case the effects of mechanical relaxation can be separated from those of aggregate diffusion. The results suggest that the dynamics of these filled elastomers are similar to the universal features observed in disordered jammed systems.
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x ray Intensity Fluctuation spectroscopy
2006Co-Authors: M SuttonAbstract:At the outset let me stress that X-ray Intensity Fluctuation spectroscopy (XIFS) is a diffraction technique. As such, the intuition and expertise that you have developed for diffraction carries over to this new technique. The tendency in this chapter is to emphasize the aspects that are different from conventional diffraction but results learned from conventional diffraction will be called upon as needed.
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x ray Intensity Fluctuation spectroscopy studies on phase ordering systems
Physical Review Letters, 2005Co-Authors: Andrei Fluerasu, M Sutton, Eric M DufresneAbstract:The order-disorder phase transition in ${\mathrm{C}\mathrm{u}}_{3}\mathrm{A}\mathrm{u}$ has been studied by x-ray Intensity Fluctuation spectroscopy. Following a quench from the high-temperature, disordered phase, the ordering kinetics is well described by a universal scaling form that can be measured by time-resolved (incoherent) x-ray scattering. By using coherent scattering, we have measured the Fluctuations about this universal scaling form. In the late stages of the ordering process, these Fluctuations give a two-time correlation function $C(q,{t}_{1},{t}_{2})$ which has a scaling form with natural variables $\ensuremath{\delta}t=|{t}_{1}\ensuremath{-}{t}_{2}|$ and $\overline{t}=\frac{({t}_{1}+{t}_{2})}{2}$. The scaling form crosses over from linear in $\overline{t}$ to ${\overline{t}}^{1/2}$. These present the first such results for a nonconserved system.
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x ray Intensity Fluctuation spectroscopy measurements of the charge density wave phases of nbse _3
Journal De Physique Iv, 2002Co-Authors: M Sutton, Yulin Li, J D Brock, R E ThorneAbstract:An introduction to X-ray Intensity Fluctuation Spectroscopy (XIFS) is given by describing its relationship to speckle from coherent sources. A brief description of the relationship of XIFS measurements to the underlying equations of motion is given. Preliminary results for the charge density wave (CDW) system NbSe 3 are then presented. Static speckle patterns are shown for the Q 1 = (0.76 0) CDW peak showing that XIFS experiments are possible in this system provided time constants are long enough. For electrical currents below threshold, a static speckle pattern is observed but for currents above threshold the speckles are smeared out showing movement of the CDW. It is also shown that above threshold, the longitudinal correlation length decreases.
John Bechhoefer - One of the best experts on this subject based on the ideXlab platform.
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two experimental tests of a Fluctuation induced first order phase transition Intensity Fluctuation microscopy at the nematic smectic a transition
Physical Review E, 2002Co-Authors: Anand Yethiraj, Ranjan Mukhopadhyay, John BechhoeferAbstract:We have developed a new, extremely sensitive real-space technique (Intensity Fluctuation microscopy) to probe the order of the nematic-smectic-A (NA) transition. Using this technique, we show that the NA transition in 4'-n-octyl-4-cyanobiphenyl (8CB) is clearly first order, contrary to calorimetric studies but in agreement with conclusions drawn from front-velocity measurements. We characterize the strength of the discontinuity at the first-order transition by the dimensionless quantity t 0 = (T N A - T * /T * . By precisely measuring t 0 , we have made the first detailed tests of predictions based on the Halperin-Lubensky-Ma (HLM) theory of Fluctuation-induced, first-order phase transitions. First, we explore the effect of an external magnetic field on the NA transition. Although modest fields (of order 10 T) are predicted to drive the weakly first-order transition in pure 8CB second order, we observe no such effect; we establish instead that the lower bound on this critical field is 30 T. Likewise, we observe no effect in mixtures of 8CB with its longer chemical homolog 4'-n-decyl-4-cyanobiphenyl (10CB). Second, we examine the dependence of t 0 as a function of 8CB-10CB mixture concentration and find that the data in mixtures with small nematic temperature range are well-fit by the parameters derived by Anisimov et al. based on calorimetric measurements. As we increase the nematic range (by using concentrations closer to pure 8CB), the measured t 0 deviates more and more from the HLM predictions. Smectic Fluctuations, which are neglected in the HLM calculation, are an obvious candidate to explain such a discrepancy, but one's naive expectation is that they would reduce t 0 below the HLM levels, whereas the observed values are too large. However, a recent renormalization-group calculation concludes that smectic Fluctuations, surprisingly, should indeed increase t 0 , explaining the observations presented here.
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two experimental tests of a Fluctuation induced first order phase transition Intensity Fluctuation microscopy at the nematic smectic a transition
Physical Review E, 2002Co-Authors: Anand Yethiraj, Ranjan Mukhopadhyay, John BechhoeferAbstract:: We have developed a new, extremely sensitive real-space technique (Intensity Fluctuation microscopy) to probe the order of the nematic-smectic-A (NA) transition. Using this technique, we show that the NA transition in 4'-n-octyl-4-cyanobiphenyl (8CB) is clearly first order, contrary to calorimetric studies but in agreement with conclusions drawn from front-velocity measurements. We characterize the strength of the discontinuity at the first-order transition by the dimensionless quantity t(0)=(T(NA)-T*)/T(*). By precisely measuring t(0), we have made the first detailed tests of predictions based on the Halperin-Lubensky-Ma (HLM) theory of Fluctuation-induced, first-order phase transitions. First, we explore the effect of an external magnetic field on the NA transition. Although modest fields (of order 10 T) are predicted to drive the weakly first-order transition in pure 8CB second order, we observe no such effect; we establish instead that the lower bound on this critical field is approximately 30 T. Likewise, we observe no effect in mixtures of 8CB with its longer chemical homolog 4'-n-decyl-4-cyanobiphenyl (10CB). Second, we examine the dependence of t(0) as a function of 8CB-10CB mixture concentration and find that the data in mixtures with small nematic temperature range are well-fit by the parameters derived by Anisimov et al. based on calorimetric measurements. As we increase the nematic range (by using concentrations closer to pure 8CB), the measured t(0) deviates more and more from the HLM predictions. Smectic Fluctuations, which are neglected in the HLM calculation, are an obvious candidate to explain such a discrepancy, but one's naive expectation is that they would reduce t(0) below the HLM levels, whereas the observed values are too large. However, a recent renormalization-group calculation concludes that smectic Fluctuations, surprisingly, should indeed increase t(0), explaining the observations presented here.
Yanhua Shih - One of the best experts on this subject based on the ideXlab platform.
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super resolution imaging using the spatial frequency filtered Intensity Fluctuation correlation
Scientific Reports, 2016Co-Authors: Jane Sprigg, Tao Peng, Yanhua ShihAbstract:We report an experimental demonstration of a nonclassical imaging mechanism with super-resolving power beyond the Rayleigh limit. When the classical image is completely blurred out due to the use of a small imaging lens, by taking advantage of the Intensity Fluctuation correlation of thermal light, the demonstrated camera recovered the image of the resolution testing gauge. This method could be adapted to long distance imaging, such as satellite imaging, which requires large diameter camera lenses to achieve high image resolution.
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the physics of ghost imaging nonlocal interference or local Intensity Fluctuation correlation
Quantum Information Processing, 2012Co-Authors: Yanhua ShihAbstract:In this special Volume on Quantum Imaging, Shapiro and Boyd present a review on The Physics of Ghost Imaging. Here I argue that their Review is incomplete, as it overlooks a form of ghost imaging that requires quantum mechanical nonlocal effects for their understanding. From the very beginning, Klyshko brought attention to the nonlocal nature of biphoton interference and biphoton imaging by introducing his “advanced wave” theory [1]. His “advanced wave” propagates backward in time from a photodetector to the source and then propagates forward in time from the source to another distant photodetector. The “advanced wave” connects the object-arm and the image-arm, as well as two independent photodetection events, in his biphoton interference and imaging model. Strekalov et al. and Pittman et al. realized nonlocal biphoton interference [2] and biphoton imaging [3] experimentally. The physics community immediately named these two experiments “ghost interference” and “ghost imaging”. Simultaneously with the experimental realization, we found that Klyshko’s advanced wave theory can be replaced by a standard quantum theory of second-order coherence in which a nonlocal biphoton wavepacket is introduced to connect the two arms and two photodetection events [4]. Soon after that, we realized that nonlocal interference and imaging are not restricted to entangled biphoton systems: it also happens in thermal radiation. Ghost imaging can be observed from thermal light in the Fresnel near-field zone in a lensless configuration [5–7]. Although nonlocality is a feature of quantum mechanics [8], this concept is not part of classical physics. In the classical theory of light, ghost imaging, especially thermal light ghost imaging, is a result of locally measured Intensity Fluctuation correlations. So this brings us to ask, is ghost imaging a nonlocal interference phenomenon (and hence quantum) or is it a result of local Intensity Fluctuation
Anand Yethiraj - One of the best experts on this subject based on the ideXlab platform.
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two experimental tests of a Fluctuation induced first order phase transition Intensity Fluctuation microscopy at the nematic smectic a transition
Physical Review E, 2002Co-Authors: Anand Yethiraj, Ranjan Mukhopadhyay, John BechhoeferAbstract:We have developed a new, extremely sensitive real-space technique (Intensity Fluctuation microscopy) to probe the order of the nematic-smectic-A (NA) transition. Using this technique, we show that the NA transition in 4'-n-octyl-4-cyanobiphenyl (8CB) is clearly first order, contrary to calorimetric studies but in agreement with conclusions drawn from front-velocity measurements. We characterize the strength of the discontinuity at the first-order transition by the dimensionless quantity t 0 = (T N A - T * /T * . By precisely measuring t 0 , we have made the first detailed tests of predictions based on the Halperin-Lubensky-Ma (HLM) theory of Fluctuation-induced, first-order phase transitions. First, we explore the effect of an external magnetic field on the NA transition. Although modest fields (of order 10 T) are predicted to drive the weakly first-order transition in pure 8CB second order, we observe no such effect; we establish instead that the lower bound on this critical field is 30 T. Likewise, we observe no effect in mixtures of 8CB with its longer chemical homolog 4'-n-decyl-4-cyanobiphenyl (10CB). Second, we examine the dependence of t 0 as a function of 8CB-10CB mixture concentration and find that the data in mixtures with small nematic temperature range are well-fit by the parameters derived by Anisimov et al. based on calorimetric measurements. As we increase the nematic range (by using concentrations closer to pure 8CB), the measured t 0 deviates more and more from the HLM predictions. Smectic Fluctuations, which are neglected in the HLM calculation, are an obvious candidate to explain such a discrepancy, but one's naive expectation is that they would reduce t 0 below the HLM levels, whereas the observed values are too large. However, a recent renormalization-group calculation concludes that smectic Fluctuations, surprisingly, should indeed increase t 0 , explaining the observations presented here.
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two experimental tests of a Fluctuation induced first order phase transition Intensity Fluctuation microscopy at the nematic smectic a transition
Physical Review E, 2002Co-Authors: Anand Yethiraj, Ranjan Mukhopadhyay, John BechhoeferAbstract:: We have developed a new, extremely sensitive real-space technique (Intensity Fluctuation microscopy) to probe the order of the nematic-smectic-A (NA) transition. Using this technique, we show that the NA transition in 4'-n-octyl-4-cyanobiphenyl (8CB) is clearly first order, contrary to calorimetric studies but in agreement with conclusions drawn from front-velocity measurements. We characterize the strength of the discontinuity at the first-order transition by the dimensionless quantity t(0)=(T(NA)-T*)/T(*). By precisely measuring t(0), we have made the first detailed tests of predictions based on the Halperin-Lubensky-Ma (HLM) theory of Fluctuation-induced, first-order phase transitions. First, we explore the effect of an external magnetic field on the NA transition. Although modest fields (of order 10 T) are predicted to drive the weakly first-order transition in pure 8CB second order, we observe no such effect; we establish instead that the lower bound on this critical field is approximately 30 T. Likewise, we observe no effect in mixtures of 8CB with its longer chemical homolog 4'-n-decyl-4-cyanobiphenyl (10CB). Second, we examine the dependence of t(0) as a function of 8CB-10CB mixture concentration and find that the data in mixtures with small nematic temperature range are well-fit by the parameters derived by Anisimov et al. based on calorimetric measurements. As we increase the nematic range (by using concentrations closer to pure 8CB), the measured t(0) deviates more and more from the HLM predictions. Smectic Fluctuations, which are neglected in the HLM calculation, are an obvious candidate to explain such a discrepancy, but one's naive expectation is that they would reduce t(0) below the HLM levels, whereas the observed values are too large. However, a recent renormalization-group calculation concludes that smectic Fluctuations, surprisingly, should indeed increase t(0), explaining the observations presented here.
Kazuhisa Ogawa - One of the best experts on this subject based on the ideXlab platform.
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Intensity Fluctuation of a gain switched semiconductor laser for quantum key distribution systems
Optics Express, 2017Co-Authors: Kensuke Nakata, Akihisa Tomita, Mikio Fujiwara, Kenichiro Yoshino, Akio Tajima, Atsushi Okamoto, Kazuhisa OgawaAbstract:Security certification of quantum key distribution (QKD) systems under practical conditions is necessary for social deployment. This article focused on the transmitter, and, in particular, investigated the Intensity Fluctuation of the optical pulses emitted by a gain-switched semiconductor laser used in QKD systems implementing decoy-BB84 protocol. A large Intensity Fluctuation was observed for low excitation, showing strong negative correlation between the adjacent pulses, which would affect the final key rate. The Fluctuation decreased and the correlation disappeared as excitation increased. Simulation with rate equations successfully reproduced the experimental results and revealed that the large Fluctuation originates from an intrinsic instability of gain-switched lasers driven periodically at a rate comparable to the inverse of carrier lifetime, as in GHz-clock QKD systems. Methods for further reduction of the Intensity Fluctuation were also discussed.