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1

Transfer of photon number statistics from coupling light to stored and retrieved probe light.  

PubMed

We report on the transfer of statistical characteristics from writing and reading coupling light to stored and retrieved probe light pulses in a ?-type electromagnetically induced transparency (EIT) scheme based on the 5S(1/2)-5P(1/2) transition of (87)Rb atoms. When the coherent probe laser pulse was stored in the EIT medium using the pseudo-thermal coupling light, the characteristics of the pseudo-thermal writing coupling light were transferred to the stored probe laser pulse because of the strong correlation between the probe and coupling light in the EIT medium. The photon number statistics of the retrieved probe light changed from Poisson distribution to Bose-Einstein distribution. Additionally, we measured the change in the properties of the retrieved light pulse due to the photon number statistics of the pseudo-thermal reading coupling light. PMID:23187485

Bae, In-Ho; Moon, Han Seb

2012-11-19

2

Detection of beamsplitting attack in a quantum cryptographic channel based on photon number statistics monitoring  

NASA Astrophysics Data System (ADS)

Quantum cryptography in theory allows distributing secure keys between two users so that any performed eavesdropping attempt would be immediately discovered. However, in practice an eavesdropper can obtain key information from multi-photon states when attenuated laser radiation is used as a source. In order to overcome this possibility, it is generally suggested to implement special cryptographic protocols, like decoy states or SARG04. We present an alternative method based on monitoring photon number statistics after detection. This method can therefore be used with any existing protocol.

Gaidash, A. A.; Egorov, V. I.; Gleim, A. V.

2014-10-01

3

Using a qubit to measure photon-number statistics of a driven thermal oscillator  

NASA Astrophysics Data System (ADS)

We demonstrate theoretically how photon-number statistics of a driven damped oscillator at finite temperature can be extracted by measuring the dephasing spectrum of a two-level system dispersively coupled to the oscillator; we thus extend the work of M. I. Dykman and M. A. Krivoglaz [Sov. Phys. Solid State 29, 210 (1987)] and J. Gambetta [Phys. Rev. A 74, 042318 (2006)]. We carefully consider the fidelity of this scheme—to what extent does the measurement reflect the initial number statistics of the mode? We also derive analytic results for the dephasing of a qubit by a driven thermal mode, and compare results obtained at different levels of approximation. Our results have relevance both to experiments in circuit cavity QED, as well as to nanoelectromechanical systems.

Clerk, A. A.; Utami, D. Wahyu

2007-04-01

4

The statistical distribution of the number of counted scintillation photons in digital silicon photomultipliers: model and validation.  

PubMed

In the design and application of scintillation detectors based on silicon photomultipliers (SiPMs), e.g. in positron emission tomography imaging, it is important to understand and quantify the non-proportionality of the SiPM response due to saturation, crosstalk and dark counts. A new type of SiPM, the so-called digital silicon photomultiplier (dSiPM), has recently been introduced. Here, we develop a model of the probability distribution of the number of fired microcells, i.e. the number of counted scintillation photons, in response to a given amount of energy deposited in a scintillator optically coupled to a dSiPM. Based on physical and functional principles, the model elucidates the statistical behavior of dSiPMs. The model takes into account the photon detection efficiency of the detector; the light yield, excess variance and time profile of the scintillator; and the crosstalk probability, dark count rate, integration time and the number of microcells of the dSiPM. Furthermore, relations for the expectation value and the variance of the number of fired cells are deduced. These relations are applied in the experimental validation of the model using a dSiPM coupled to a LSO:Ce,Ca scintillator. Finally, we propose an accurate method for the correction of energy spectra measured with dSiPM-based scintillation detectors. PMID:22796633

van Dam, Herman T; Seifert, Stefan; Schaart, Dennis R

2012-08-01

5

Generalized binomial distribution in photon statistics  

E-print Network

The photon-number distribution between two parts of a given volume is found for an arbitrary photon statistics. This problem is related to the interaction of a light beam with a macroscopic device, for example a diaphragm, that separates the photon flux into two parts with known probabilities. To solve this problem, a Generalized Binomial Distribution (GBD) is derived that is applicable to an arbitrary photon statistics satisfying probability convolution equations. It is shown that if photons obey Poisson statistics then the GBD is reduced to the ordinary binomial distribution, whereas in the case of Bose-Einstein statistics the GBD is reduced to the Polya distribution. In this case, the photon spatial distribution depends on the phase-space volume occupied by the photons. This result involves a photon bunching effect, or collective behavior of photons that sharply differs from the behavior of classical particles. It is shown that the photon bunching effect looks similar to the quantum interference effect.

Aleksey Ilyin

2014-06-11

6

Generalized binomial distribution in photon statistics  

E-print Network

Photon-number distribution among two parts of a given volume is found in case of an arbitrary photon statistics. This problem is related to the interaction of light beam with a macroscopic device, for example a diaphragm, that separates the photon flux into two parts with known probabilities. To solve this problem, a Generalized Binomial Distribution (GBD) is derived that is applicable to an arbitrary photon statistics satisfying probability convolution equations. It is shown that if photons obey the Poisson statistics then the GBD is reduced to the ordinary binomial distribution whereas in case of Bose-Einstein statistics the GBD is reduced to the Polya distribution. In this case, the photon spatial distribution depends on the phase-space volume occupied by the photons. This result involves a photon bunching effect, or such collective behavior of photons that sharply differs from the behavior of classical particles. It is shown that the photon bunching effect looks similar to the quantum interference effect.

Aleksey Ilyin

2014-06-11

7

Photon statistics dispersion in excitonic composites  

E-print Network

Linear media are predicted to exist whose relative permiability is an operator in the space of quantum states of light. Such media are characterized by a photon statistics--dependent refractive index. This indicates a new type of optical dispersion -- the photon statistics dispersion. Interaction of quantum light with such media modifies the photon number distribution and, in particular, the degree of coherence of light. An excitonic composite -- a collection of noninteracting quantum dots -- is considered as a realization of the medium with the photon statistics dispersion. Expressions are derived for generalized plane waves in an excitonic composite and input--output relations for a planar layer of the material. Transformation rules for different photon initial states are analyzed. Utilization of the photon statistics dispersion in potential quantum--optical devices is discussed.

G. Ya. Slepyan; S. A. Maksimenko

2006-05-22

8

Photon statistics of intense entangled photon pulses  

NASA Astrophysics Data System (ADS)

Time- and frequency-gated two-photon counting is given by a four-time correlation function of the electric field. This reduces to two times with purely time gating. We calculate this function for entangled photon pulses generated by parametric down-conversion. At low intensity, the pulses consist of well-separated photon pairs, and crossover to squeezed light as the intensity is increased. This is illustrated by the two-photon absorption signal of a three-level model, which scales linearly for a weak pump intensity where both photons come from the same pair, and gradually becomes nonlinear as the intensity is increased. We find that the strong frequency correlations of entangled photon pairs persist even for higher photon numbers. This could help facilitate the application of these pulses to nonlinear spectroscopy, where these correlations can be used to manipulate congested signals.

Schlawin, Frank; Mukamel, Shaul

2013-09-01

9

Photon arrival time quantum random number generation  

Microsoft Academic Search

We present an efficient random number generator based on the randomness present in photon emission and detection. The interval between successive photons from a light source with Poissonian statistics is separated into individual time bins, which are then used to create several random bits per detection event. Using a single-photon counter and FPGA-based data processing allows for a cost-efficient and

MICHAEL ALAN WAYNE; Evan R. Jeffrey; Gleb M. Akselrod; Paul G. Kwiat

2009-01-01

10

Reconstruction of Photon Number Distribution without Relying on Photon Number-Resolving Detector  

NASA Astrophysics Data System (ADS)

The photon number distribution is reconstructed from the measured statistics of vacuum states in single-photon detection. Numerical results are presented for the coherent, thermal, number and squeezed-vacuum states. The quantum efficiency of single-photon detection should be high for the successful evaluation of the number state. The quantum efficiency provides the marginal influence for the evaluation of the coherent, thermal and squeezed-vacuum states. However, the accuracy of the reconstructed photon number distribution of the squeezed-vacuum state is low even though the quantum efficiency is unity. For a more accurate reconstruction, we must obtain a priori information on the photon number distribution of the squeezed-vacuum state.

Yoshizawa, Akio; Tsuchida, Hidemi

2005-11-01

11

Lorentz invariant photon number density  

E-print Network

A Lorentz invariant positive definite expression for photon number density is derived as the absolute square of the invariant scalar product of a polarization sensitive position eigenvector and the photon wave function. It is found that this scalar product is independent of the form chosen for the wave function and that the normalized positive frequency vector potential-electric field pair is a convenient choice of wave function in the presence of matter. The number amplitude describing a localized state is a delta-function at the instant at which localization and detection are seen as simultaneous.

Margaret Hawton

2008-04-23

12

Photon Counts Statistics in Leukocyte Cell Dynamics  

NASA Astrophysics Data System (ADS)

In the present experiment ultra-weak photon emission/ chemiluminescence from isolated neutrophils was recorded. It is associated with the production of reactive oxygen species (ROS) in the "respiratory burst" process which can be activated by PMA (Phorbol 12-Myristate 13-Acetate). Commonly, the reaction is demonstrated utilizing the enhancer luminol. However, with the use of highly sensitive photomultiplier equipment it is also recorded without enhancer. In that case, it can be hypothesized that photon count statistics may assist in understanding the underlying metabolic activity and cooperation of these cells. To study this hypothesis leukocytes were stimulated with PMA and increased photon signals were recorded in the quasi stable period utilizing Fano factor analysis at different window sizes. The Fano factor is defined by the variance over the mean of the number of photon within the observation time. The analysis demonstrated that the Fano factor of true signal and not of the surrogate signals obtained by random shuffling increases when the window size increased. It is concluded that photon count statistics, in particular Fano factor analysis, provides information regarding leukocyte interactions. It opens the perspective to utilize this analytical procedure in (in vivo) inflammation research. However, this needs further validation.

van Wijk, Eduard; van der Greef, Jan; van Wijk, Roeland

2011-12-01

13

Tunable photon statistics in weakly nonlinear photonic molecules  

E-print Network

In recent studies [Liew et al., Phys. Rev. Lett. 104, 183601 (2010); Bamba et al., Phys. Rev. A 83, 021802(R) (2011)], due to destructive interference between different paths for two-photon excitation, strong photon antibunching can be obtained in a photonic molecule consisting of two coupled cavity modes with weak Kerr nonlinearity when one of the cavity modes is driven resonantly. Here, we study the photon statistics in a nonlinear photonic molecule with both the two cavity modes being driven coherently. We show that the statistical properties of the photons can be controlled by regulating the coupling constant between the cavity modes, the strength ratio and the relative phase between the driving fields. The photonic molecules with two driven modes can be used to generate tunable single-photon sources or controlled photonic quantum gates with weak Kerr nonlinearity.

Xun-Wei Xu; Yong Li

2014-07-11

14

Relativistic statistical thermodynamics of dense photon gas  

NASA Astrophysics Data System (ADS)

We discuss some aspects of interactions of high-frequency electromagnetic waves with plasmas, assuming that the intensity of radiation is sufficiently large, so that the photon-photon interaction is more likely than the photon-plasma particle interaction. In the stationary limit, solving the kinetic equation of the photon gas, we derive a distribution function. With this distribution function at hand, we investigate the adiabatic photon self-capture and obtain the number density of the trapped photons. We employ the distribution function to calculate the thermodynamic quantities for the photon gas. Having expressions of the entropy and the pressure of the photon gas, we define the heat capacities and exhibit the existence of the ratio of the specific heats ? , which equals 7/6 for nonrelativistic temperatures. In addition, we disclose the magnitude of the mean square fluctuation of the number of photons. Finally, we discuss the uniform expansion of the photon gas.

Tsintsadze, Levan N.; Kishimoto, Yasuaki; Callebaut, Dirk K.; Tsintsadze, Nodar L.

2007-07-01

15

Photon statistics of light in semiconductor microcavities  

Microsoft Academic Search

We investigate the photon statistics in the light emitted by a microcavity containing a semiconductor quantum well. An analytical expression of the light-emitted autocorrelation function in the weak pumping regime is derived. We discuss photon statistical similarities with an atomic cavity.

H. Eleuch

2008-01-01

16

Photon splitting cascades and a new statistics  

Microsoft Academic Search

Photon splitting cascades in a magnetic field are considered. It is shown, in the stochastic limit approximation, that photons in cascades might form entangled states (``triphons'') and that they obey not Bose but a new type of statistics, the so called infinite or quantum Boltzmann statistics. These states belong to an interacting Fock space which is a generalization of the

L. Accardi; I. Ya. Aref'eva; I. V. Volovich

1997-01-01

17

Laser photon statistics in the feedback loop  

E-print Network

A mere correspondence between the electron statistics and the photon one vanishes in the feedback loop (FBL). It means that the direct photodetection, supplying us with the electron statistics, does not provide us with a wished information about the laser photon statistics. For getting this information we should think up another measurement procedure, and we in the article suggest applying the three-level laser as a auxiliary measuring device. This laser has impressive property, namely, its photon statistics survive information about the initial photon statistics of the laser which excites coherently the three-level medium. Thus, if we choose the laser in the FBL as exciting the three-level laser, then we have an possibility to evaluate its initial photon statistics by means of direct detecting the three-level laser emission. Finally, this approach allows us to conclude the feedback is not capable of creating a regularity in the laser light beam. Contrary, the final photon fluctuations turn out to be always even bigger. The mentioned above feature of the three-level laser takes place only for the strong interaction between the lasers (exciting and excited). It means the initial state of the exciting laser is changed dramatically, so our measurement procedure can not be identified with some non-demolition one.

T. Yu. Golubeva; Yu. M. Golubev

2005-04-23

18

On Photon Statistics in Variable Media  

E-print Network

We find explicit solutions of the Heisenberg equations of motion for a quadratic Hamiltonian, describing a generic model of variable media, in the case of multi-parameter squeezed input photons. The corresponding photon statistics are also derived in the Schroedinger picture in an abstract operator setting. Their time evolution is given in terms of solutions of certain Ermakov-type system. The unitary transformation and an extension of the squeeze/evolution operator are introduced formally.

Sergey I. Kryuchkov; Erwin Suazo; Sergei K. Suslov

2014-01-13

19

Avalanche-photodiode-based photon counter echo photon number resolving  

NASA Astrophysics Data System (ADS)

The solid state photodetectors based on silicon avalanche photodiodes operated in Geiger mode are used for detection of echo signal in laser ranging experiments. The avalanche process nonlinearity enhance the influence of starting conditions to avalanche grow of photodiode output signal. This is the reason why the internal delay of this type of detectors is depended on detected signal intensity, i.e. in case of weak signal it is depended on number of detected photons. The dependence is in the range of 0-200 ps for photon numbers 1-1000 photons. The active quenching and gating circuit with time walk compensation has been constructed to eliminate this effect (Kirchner, 1998). In our experiment, we have used the outputs of the compensation circuit to estimate the photon numbers detected on a shot by shot basis simultaneously with original required time interval estimation. The mutual time difference between the compensated and uncompensated output pulses corresponds to the photon number. Monitoring this time difference by the picosecond event timing device enabled us to monitor the echo signal strength fluctuation on a shot by shot basis in a laser ranging. The experimental results will be presented.

Blazej, Josef; Prochazka, Ivan; Hamal, Karel

2004-01-01

20

Statistical Treatment of Nominal Numbers.  

National Technical Information Service (NTIS)

An attempt is made to find an answer to Lord's parable of the football numbers by demonstrating that he ignored the well known principle that a measurement operation should be consistent over allowable transformations of scale. An example is given to demo...

D. R. Harris

1971-01-01

21

Statistical approaches for probing single-molecule dynamics photon-by-photon  

E-print Network

Statistical approaches for probing single-molecule dynamics photon-by-photon Haw Yang1 , X. Sunney 02138, USA Received 19 December 2001 Abstract The recently developed photon-by-photon approach [H. Yang, each photon represents a data point, thereby affording better statistics. Here, we utilize

Xie, Xiaoliang Sunney

22

Probing the Conformations of Single Molecule via Photon Counting Statistics  

E-print Network

We suggest an approach to detect the conformation of single molecule by using the photon counting statistics. The generalized Smoluchoswki equation is employed to describe the dynamical process of conformational change of single molecule. The resonant trajectories of the emission photon numbers $$ and the Mandel's $Q$ parameter, in the space of conformational coordinates $\\bm{\\mathcal{X}}$ and frequency $\\omega_L$ of external field ($\\bm{\\mathcal{X}}-\\omega_L$ space), can be used to rebuild the conformation of the single molecule. As an example, we consider Thioflavin T molecule. It demonstrates that the results of conformations extracted by employing the photon counting statistics is excellent agreement with the results of {\\it ab initio} computation.

Peng, Yonggang; Yang, Chuanlu; Zheng, Yujun

2014-01-01

23

Linking numbers, spin, and statistics of solitons  

NASA Technical Reports Server (NTRS)

The spin and statistics of solitons in the (2 + 1)- and (3 + 1)-dimensional nonlinear sigma models is considered. For the (2 + 1)-dimensional case, there is the possibility of fractional spin and exotic statistics; for 3 + 1 dimensions, the usual spin-statistics relation is demonstrated. The linking-number interpretation of the Hopf invariant and the use of suspension considerably simplify the analysis.

Wilczek, F.; Zee, A.

1983-01-01

24

Interaction of Fixed Number of Photons with Retinal Rod Cells  

NASA Astrophysics Data System (ADS)

New tools and approaches of quantum optics offer a unique opportunity to generate light pulses carrying a precise number of photons. Accurate control over the light pulses helps to improve the characterization of photoinduced processes. Here, we study interaction of a specialized light source which provides flashes containing just one photon, with retinal rod cells of Xenopus laevis toads. We provide unambiguous proof of the single-photon sensitivity of rod cells without relying on the statistical modeling. We determine their quantum efficiencies without the use of any precalibrated detectors and obtain the value of (29±4.7)%. Our approach provides the path for future studies and applications of quantum properties of light in phototransduction, vision, and photosynthesis.

Phan, Nam Mai; Cheng, Mei Fun; Bessarab, Dmitri A.; Krivitsky, Leonid A.

2014-05-01

25

Photon Statistics of a Single Atom Intracavity EIT-Kerr System  

E-print Network

We explore the photon statistics of light emitted from a system comprising a single four--level atom strongly coupled to a high-finesse optical cavity mode which is driven by a coherent laser field. In the weak driving regime this system is found to exhibit a photon blockade effect. For intermediate driving strengths we find a sudden change in the photon statistics of the light emitted from the cavity. Photon antibunching switches to photon bunching over a very narrow range of intracavity photon number. It is proven that this sudden change in photon statistics occurs due to the existence of robust quantum interference of transitions between the dressed states of the atom-cavity system. Furthermore, it is shown that the strong photon bunching is a nonclassical effect for certain values of driving field strength, violating classical inequalities for field correlations.

S. Rebi?; A. S. Parkins; S. M. Tan

2002-02-13

26

Statistical Applets: Law of Large Numbers  

NSDL National Science Digital Library

Created by authors Duckworth, McCabe, Moore and Sclove for W.H. Freeman and Co., this applet is designed to help students understand the Law of Large Numbers by simulating rolling dice. The applet graphs the mean of the sum of the rolls for user specified conditions. This applet accompanies "Practice of Business Statistics;" however, it can be used without this text. Even though brief, this is still a nice interactive resource for an introductory statistics course.

Duckworth, William; Mccabe, George; Moore, David; Sclove, Stanley

2009-03-06

27

Photon statistics: Nonlinear spectroscopy of single quantum systems Shaul Mukamel  

E-print Network

Photon statistics: Nonlinear spectroscopy of single quantum systems Shaul Mukamel Department of their infor- mation content. A general formal expression for photon counting statistics from single quantum counting statistics which had proven to be a most valuable measure of coherence has been formulated

Mukamel, Shaul

28

Statistical fitting accuracy in photon correlation spectroscopy  

NASA Technical Reports Server (NTRS)

Continuing our experimental investigation of the fitting accuracy associated with photon correlation spectroscopy, we collect 150 correlograms of light scattered at 90 deg from a thermostated sample of 91-nm-diameter, polystyrene latex spheres in water. The correlograms are taken with two correlators: one with linearly spaced channels and one with geometrically spaced channels. Decay rates are extracted from the single-exponential correlograms with both nonlinear least-squares fits and second-order cumulant fits. We make several statistical comparisons between the two fitting techniques and verify an earlier result that there is no sample-time dependence in the decay rate errors. We find, however, that the two fitting techniques give decay rates that differ by 1 percent.

Shaumeyer, J. N.; Briggs, Matthew E.; Gammon, Robert W.

1993-01-01

29

Fast recognition of single molecules based on single event photon statistics  

E-print Network

Mandel Q-parameter, which is determined from single event photon statistics, provides an alternative to differentiate single-molecule with fluorescence detection. In this work, by using the Q-parameter of the sample fluorescence compared to that of an ideal double-molecule system with the same average photon number, we present a novel and fast approach for identifying single molecules based on single event photon statistics analyses, compared with commonly used two-time correlation measurements. The error estimates for critical values of photon statistics are also presented for single-molecule determination.

Shuangli Dong; Tao Huang; Yuan Liu; Jun Wang; Guofeng Zhang; Liantuan Xiao+; Suotang Jia

2007-08-02

30

Induced photon statistics in three-level lasers  

E-print Network

The statistical properties of three-level lasing are investigated theoretically. It is assumed that the three-level medium is coherently excited by another laser with an arbitrary photon statistics. It is proved that, under the specific conditions, the photon statistics of the three-level laser duplicate the photon statistics of the exciting laser. We call this phenomenon an induced photon statistics. We suggest to use this to analyze the statistical properties of a laser involved into a feedback process. Applying this laser for the coherent pump of a three-level laser, we can follow its photon statistics by means of direct following the three-level generation. In accordance with [H. M. Wiseman and G. J. Milburn, Phys. Rev. A, 49, 1350-1366 (1994)], we conclude that the feedback in itself is unable to generate the non-classical manifestation in the laser field.

T. Golubeva; Yu. Golubev

2006-04-12

31

Photon number squeezed states in semiconductor lasers  

NASA Technical Reports Server (NTRS)

Electromagnetic fields, with the noise on one quadrature component reduced to below the quantum mechanical zero-point fluctuation level and the noise on the other quadrature component enhanced to above it, are currently of great interest in quantum optics because of their potential applications to various precision measurements. Such squeezed states of light are usually produced by imposing nonlinear unitary evolution on coherent (or vacuum) states. On the other hand, squeezed states with reduced photon number noise and enhanced phase noise are generated directly by a constant current-driven semiconductor laser. This is the simplest scheme for the generation of nonclassical light, and so far it has yielded the largest quantum noise reduction. The mutual coupling between a lasing junction and an external electrical circuit provides opportunities for exploring the macroscopic and microscopic quantum effects in open systems.

Yamamoto, Yoshihisa; Machida, Susumu; Richardson, Wayne H.

1992-01-01

32

Room temperature photon number resolving detector at telecom wavelengths  

E-print Network

Large dynamic range room temperature photon number resolving (PNR) detectors can be very useful for measuring very low light intensities and for analyzing multiphoton quantum states. In this paper we present a PNR detector based on the up-conversion (UC) of telecom signal into visible wavelength and on its detection by a thermoelectrically cooled multi-pixel silicon avalanche photodiodode (APD), also known as Silicon Photon Multiplier (SiPM). An efficiency of 4% is attained and the poissonian statistics of input coherent states is maintained up to approximately 20 simultaneous detections. The cross-talk effects on the detected signal are estimated in order to properly calibrate the detector. This scheme can be used at arbitrary wavelengths above the visible spectral window with appropriate up-conversion.

Enrico Pomarico; Bruno Sanguinetti; Rob Thew; Hugo Zbinden

2010-03-29

33

Laser ranging at few-photon level by photon-number-resolving detection.  

PubMed

Sensitive laser ranging was demonstrated at few-photon level using photon-number-resolving (PNR) detectors. The reflected photon pulses from a non-cooperation remote target were distinguished in a sunlight environment of 2.5×103??lx by setting the discrimination threshold at 5-photon level. By comparing the detected photon numbers, two remote targets with different reflection coefficients were well recognized. PNR detection facilitated remote laser ranging of few-photon sensitivity with similar capabilities of linear optical detectors. This technique avoids photon-counting saturation and is important for ultra-long distance LIDAR and 3D imaging at a few photon level. PMID:24979422

Bao, Zeyu; Liang, Yan; Wang, Zhiyuan; Li, Zhaohui; Wu, E; Wu, Guang; Zeng, Heping

2014-06-20

34

Photon Statistics and Coherence in Light Emission from a Random Laser Lucia Florescu and Sajeev John  

E-print Network

Photon Statistics and Coherence in Light Emission from a Random Laser Lucia Florescu and Sajeev August 2003; published 2 July 2004) We derive the photon number probability distribution of light emitted from a random multiple-light- scattering medium with gain, using a generalized master equation. Our

John, Sajeev

35

Imaging with a small number of photons  

E-print Network

Low-light-level imaging techniques have application in many diverse fields, ranging from biological sciences to security. We demonstrate a single-photon imaging system based on a time-gated inten- sified CCD (ICCD) camera in which the image of an object can be inferred from very few detected photons. We show that a ghost-imaging configuration, where the image is obtained from photons that have never interacted with the object, is a useful approach for obtaining images with high signal-to-noise ratios. The use of heralded single-photons ensures that the background counts can be virtually eliminated from the recorded images. By applying techniques of compressed sensing and associated image reconstruction, we obtain high-quality images of the object from raw data comprised of fewer than one detected photon per image pixel.

Morris, Peter A; Bell, Jessica; Boyd, Robert W; Padgett, Miles J

2014-01-01

36

Information transmission with photon-number-squeezed light  

Microsoft Academic Search

Several methods have been proposed for the generation of photon-number-squeezed (sub-Poisson) light by imparting to the photon stream and anticorrelation that regularizes the times of arrival of the photons. This is accomplished by means of control of the excitation or emission process or by feedback, using a copy of the photon point processes when the emissions occur in parts. Possible

BAHAA E. A. SALEH; MALVIN C. TEICH

1992-01-01

37

Quantum nondemolition measurement of small photon numbers using stored light  

NASA Astrophysics Data System (ADS)

We propose a scheme for realizing a quantum nondemolition (QND) measurement of a small number of optical photons. Our scheme has two stages: First, we couple a propagating light pulse with fixed photon number to a trapped cold atomic gas within a cavity, such that the pulse is stored within a collective polariton mode. Second, a small-photon-number measurement is engineered by monitoring the cavity-transmission spectrum. Since the polariton mode profile is preserved during the process of detecting the spectrum, photon-number QND measurements could be achieved by retrieving the light pulse from the polariton mode. We also discuss a method which uses QND measurements to generate small-photon Fock states.

Liang, L.; Lin, G. W.; Hao, Y. M.; Niu, Y. P.; Gong, S. Q.

2014-11-01

38

Misused Statistics: Straight Talk for Twisted Numbers.  

ERIC Educational Resources Information Center

Numerous misuses of statistics are described and illustrated, and ways of recognizing and avoiding such misuse are discussed. The following five categories of statistical misuse are identified: a lack of knowledge of the subject matter, the quality of the basic data, the preparation of the study and the report, the statistical methodology, and a…

Jaffe, A. J.; Spirer, Herbert F.

39

Accessing photon bunching with photon number resolving multi-pixel detector  

E-print Network

In quantum optics and its applications, there is an urgent demand for photon-number resolving detectors. Recently, there appeared multi-pixel detectors (MPPC) that are able to distinguish between 1,2,..10 photons. At the same time, strong coupling between different pixels (cross-talk) hinders their photon-number resolution. In this work, we suggest a method for `filtering out' the cross-talk effect in the measurement of intensity correlation functions.

Dmitry A. Kalashnikov; Si-Hui Tan; Maria V. Chekhova; Leonid A. Krivitsky

2010-12-10

40

Nonlinear Polarization Interferometer for Photon-Number Squeezed Light Generation  

Microsoft Academic Search

We propose a new scheme of photon-number squeezed light generation using a nonlinear polarization interferometer which is constructed by the cascade connection of two polarization-maintaining fibers. Since it is possible to generate photon-number squeezed light by only passing an optical pulse through an optical fiber without spatial alignment, it is expected that the squeezed light can easily and stably be

Junichi Higuchi; Norihiko Nishizawa; Masakazu Mori; Kazuo Yamane; Toshio Goto

2001-01-01

41

High photon number path entanglement in the interference of spontaneously downconverted photon pairs with coherent laser light  

E-print Network

We show that the quantum interference between downconverted photon pairs and photons from coherent laser light can produce a maximally path entangled N-photon output component with a fidelity greater than 90% for arbitrarily high photon numbers. A simple beam splitter operation can thus transform the 2-photon coherence of down-converted light into an almost optimal N-photon coherence.

Holger F. Hofmann; Takafumi Ono

2007-05-01

42

Necessary and Sufficient Classicality Conditions on Photon Number Distributions  

E-print Network

We exploit results on the classical Stieltjes moment problem to obtain completely explicit necessary and sufficient conditions for the photon number distribution p(n) of a radiation field mode to be classical. These conditions are given in two forms - respectively local and global in the individual photon number probabilities. Central to the first approach is the recognition of the important fact that the quantities n!p(n) are moments of a quasiprobability distribution, notwithstanding the fact that p(n)'s can by themselves be considered as a probability distribution over the nonnegative integers. This leads to local classicality conditions involving p(n)'s for only a small number of values of n. This local approach enables us to present detailed quantitative statements on the connection between nonclassicality and oscillations in the photon number distribution. The second approach is in terms of the traditional factorial moments of p(n). Equivalence of the two approaches is established.

Simon, R; Mukunda, N; Selvadoray, Mary

1997-01-01

43

Necessary and Sufficient Classicality Conditions on Photon Number Distributions  

E-print Network

We exploit results on the classical Stieltjes moment problem to obtain completely explicit necessary and sufficient conditions for the photon number distribution p(n) of a radiation field mode to be classical. These conditions are given in two forms - respectively local and global in the individual photon number probabilities. Central to the first approach is the recognition of the important fact that the quantities n!p(n) are moments of a quasiprobability distribution, notwithstanding the fact that p(n)'s can by themselves be considered as a probability distribution over the nonnegative integers. This leads to local classicality conditions involving p(n)'s for only a small number of values of n. This local approach enables us to present detailed quantitative statements on the connection between nonclassicality and oscillations in the photon number distribution. The second approach is in terms of the traditional factorial moments of p(n). Equivalence of the two approaches is established.

R. Simon; Mary Selvadoray; Arvind; N. Mukunda

1997-09-13

44

Ultrabroadband direct detection of nonclassical photon statistics at telecom wavelength.  

PubMed

Broadband light sources play essential roles in diverse fields, such as high-capacity optical communications, optical coherence tomography, optical spectroscopy, and spectrograph calibration. Although a nonclassical state from spontaneous parametric down-conversion may serve as a quantum counterpart, its detection and characterization have been a challenging task. Here we demonstrate the direct detection of photon numbers of an ultrabroadband (110 nm FWHM) squeezed state in the telecom band centred at 1535 nm wavelength, using a superconducting transition-edge sensor. The observed photon-number distributions violate Klyshko's criterion for the nonclassicality. From the observed photon-number distribution, we evaluate the second- and third-order correlation functions, and characterize a multimode structure, which implies that several tens of orthonormal modes of squeezing exist in the single optical pulse. Our results and techniques open up a new possibility to generate and characterize frequency-multiplexed nonclassical light sources for quantum info-communications technology. PMID:24694515

Wakui, Kentaro; Eto, Yujiro; Benichi, Hugo; Izumi, Shuro; Yanagida, Tetsufumi; Ema, Kazuhiro; Numata, Takayuki; Fukuda, Daiji; Takeoka, Masahiro; Sasaki, Masahide

2014-01-01

45

Apollo by the Numbers: A Statistical Reference  

NASA Technical Reports Server (NTRS)

The purpose of this work is to provide researchers, students, and space enthusiasts with a comprehensive reference for facts about Project Apollo, America's effort to put humans in the Moon. Research for this work started in 1988, when the author discovered that, despite the number of excellent books that focused on the drama of events that highlighted Apollo, there were none that focused on the drama of the numbers. This book is separated into two parts. The first part contains narratives for the Apollo 1 fire and the 11 flown Apollo missions. Included after each narrative is a series of data tables, followed by a comprehensive timeline of events from just before liftoff to just after crew and spacecraft recovery. The second part contains more than 50 tables. These tables organize much of the data from the narratives in one place so they can be compared among all missions. The tables offer additional data as well. The reader can select a specific mission narrative or specific data table by consulting the Table of Contents.

Orloff, Richard; Garber, Stephen (Technical Monitor)

2000-01-01

46

REVSTAT Statistical Journal Volume 8, Number 1, June 2010, 5780  

E-print Network

with astronomical measurement error, in fisheries statistics, as a way of looking at fish stocks, in medical of errors in variables modelling Given a set of variables, a common statistical procedure is to try and findREVSTAT ­ Statistical Journal Volume 8, Number 1, June 2010, 57­80 AN OVERVIEW OF LINEAR STRUCTURAL

Alves, Maria Isabel Fraga

47

Sum-frequency generation from photon number squeezed light  

NASA Technical Reports Server (NTRS)

We investigate the quantum fluctuations of the fields produced in sum-frequency (SF) generation from light initially in the photon number squeezed state. It is found that, to the fourth power term, the output SF light is sub-Poissonian whereas the quantum fluctuations of the input beams increase. Quantum anticorrelation also exists in SF generation.

Wu, Ling-An; Du, Cong-Shi; Wu, Mei-Juan; Li, Shi-Qun

1994-01-01

48

Entangled photon electron states and the number-phase minimum uncertainty states of the photon field  

Microsoft Academic Search

The exact analytic solutions of the energy eigenvalue equation of the system consisting of a free electron and one mode of the quantized radiation field are used for studying the physical meaning of a class of number-phase minimum uncertainty states. The states of the mode which minimize the uncertainty product of the photon number and the Suskind and Glogower (1964

S. Varró

2008-01-01

49

Thermal balance and photon-number quantization in layered structures  

NASA Astrophysics Data System (ADS)

The quantization of the electromagnetic field in lossy and dispersive dielectric media has been widely studied during the last few decades. However, several aspects of energy transfer and its relation to consistently defining position-dependent ladder operators for the electromagnetic field in nonequilibrium conditions have partly escaped the attention. In this work we define the position-dependent ladder operators and an effective local photon-number operator that are consistent with the canonical commutation relations and use these concepts to describe the energy transfer and thermal balance in layered geometries. This approach results in a position-dependent photon-number concept that is simple and consistent with classical energy conservation arguments. The operators are formed by first calculating the vector potential operator using Green's function formalism and Langevin noise source operators related to the medium and its temperature, and then defining the corresponding position-dependent annihilation operator that is required to satisfy the canonical commutation relations in arbitrary geometry. Our results suggest that the effective photon number associated with the electric field is generally position dependent and enables a straightforward method to calculate the energy transfer rate between the field and the local medium. In particular, our results predict that the effective photon number in a vacuum cavity formed between two lossy material layers can oscillate as a function of the position suggesting that also the local field temperature oscillates. These oscillations are expected to be directly observable using relatively straightforward experimental setups in which the field-matter interaction is dominated by the coupling to the electric field. The approach also gives further insight on separating the photon ladder operators into the conventional right and left propagating parts and on the anomalies reported for the commutation relations of the corresponding operators within optical cavities.

Partanen, Mikko; Häyrynen, Teppo; Oksanen, Jani; Tulkki, Jukka

2014-03-01

50

Theory of photon statistics and optical coherence in a multiple-scattering random-laser medium  

NASA Astrophysics Data System (ADS)

We derive the photon-number probability distribution and the resulting degree of second-order optical coherence for light emission from a uniformly distributed active species within a multiple-light-scattering medium. This is obtained from a master equation describing the probability distribution for photons in the vicinity of position r, traveling with a wave vector k, related, in turn, to a coarse-grained average of the optical Wigner coherence function. Using a simple model for isotropic, spatially uncorrelated scatterers, this reduces to a generalization of the master equation of a conventional laser in which the medium behaves like a random collection of low-quality factor cavities that are coupled by photon diffusion between a given cavity and its neighbors. Laserlike coherence, on average, is obtained in the random laser above a specific pumping threshold. Photon-number statistics above and below the lasing threshold are computed by first assuming that the atomic response to the local electromagnetic fields is nearly instantaneous. Corrections to this simple model, arising from nonadiabatic atomic dynamics, are then estimated. The dependence of the photon statistics on scatterer density, gain concentration, and position within a sample reveal that, on average, increase of the scattering strength (decrease of the photon transport mean free path) in the medium leads to a sharper peak in the local photon-number distribution, characteristic of increased local coherence in the optical field. We also evaluate the coherence of the output field at points outside the random-laser medium. This is a weighted average of radiation emitted at different positions in the sample, exhibiting varying degrees of coherence due to variations in the local pumping intensity.

Florescu, Lucia; John, Sajeev

2004-04-01

51

Statistical measures and magic numbers in metal clusters  

NASA Astrophysics Data System (ADS)

In this work, a shell model for metal clusters up to 220 valence electrons is used to obtain the fractional occupation probabilities of the electronic orbitals. Then, the calculation of a statistical measure of complexity and the Fisher-Shannon information is carried out. An increase of both magnitudes with the number of valence electrons is observed. The shell structure is reflected by the behavior of the statistical complexity. The magic numbers are indicated by the Fisher-Shannon information. So, as in the case of atomic nuclei, the study of statistical indicators also unveil the existence of magic numbers in metal clusters.

Sañudo, Jaime; López-Ruiz, Ricardo

2011-04-01

52

Thermal balance and photon-number quantization in layered structures  

E-print Network

The quantization of the electromagnetic field in lossy and dispersive dielectric media has been widely studied during the last few decades. However, several aspects of energy transfer and its relation to consistently defining position-dependent ladder operators for the electromagnetic field in nonequilibrium conditions have partly escaped the attention. In this work we define the position-dependent ladder operators and an effective local photon-number operator that are consistent with the canonical commutation relations and use these concepts to describe the energy transfer and thermal balance in layered geometries. This approach results in a position-dependent photon-number concept that is simple and consistent with classical energy conservation arguments. The operators are formed by first calculating the vector potential operator using Green's function formalism and Langevin noise source operators related to the medium and its temperature, and then defining the corresponding position-dependent annihilation ...

Partanen, Mikko; Oksanen, Jani; Tulkki, Jukka

2014-01-01

53

Thermal balance and photon-number quantization in layered structures  

E-print Network

The quantization of the electromagnetic field in lossy and dispersive dielectric media has been widely studied during the last few decades. However, several aspects of energy transfer and its relation to consistently defining position-dependent ladder operators for the electromagnetic field in nonequilibrium conditions have partly escaped the attention. In this work we define the position-dependent ladder operators and an effective local photon-number operator that are consistent with the canonical commutation relations and use these concepts to describe the energy transfer and thermal balance in layered geometries. This approach results in a position-dependent photon-number concept that is simple and consistent with classical energy conservation arguments. The operators are formed by first calculating the vector potential operator using Green's function formalism and Langevin noise source operators related to the medium and its temperature, and then defining the corresponding position-dependent annihilation operator that is required to satisfy the canonical commutation relations in arbitrary geometry. Our results suggest that the effective photon number associated with the electric field is generally position dependent and enables a straightforward method to calculate the energy transfer rate between the field and the local medium. In particular, our results predict that the effective photon number in a vacuum cavity formed between two lossy material layers can oscillate as a function of the position suggesting that also the local field temperature oscillates. These oscillations are expected to be directly observable using relatively straightforward experimental setups in which the field-matter interaction is dominated by the coupling to the electric field.

Mikko Partanen; Teppo Häyrynen; Jani Oksanen; Jukka Tulkki

2014-03-17

54

Measurements of the dependence of the photon-number distribution on the number of modes in parametric down-conversion  

NASA Astrophysics Data System (ADS)

Optical parametric down-conversion (PDC) is a central tool in quantum optics experiments. The number of collected down-converted modes greatly affects the quality of the produced photon state. We use Silicon Photomultiplier (SiPM) number-resolving detectors in order to directly observe the photon-number distribution of a PDC source, and show its dependence on the number of collected modes. Additionally, we show how the stimulated emission of photons and the partition of photons into several modes determine the overall photon number. We present a novel analytical model for the optical crosstalk effect in SiPM detectors, and use it to analyze the results.

Dovrat, L.; Bakstein, M.; Istrati, D.; Shaham, A.; Eisenberg, H. S.

2012-01-01

55

Measurements of the dependence of the photon-number distribution on the number of modes in parametric down-conversion.  

PubMed

Optical parametric down-conversion (PDC) is a central tool in quantum optics experiments. The number of collected down-converted modes greatly affects the quality of the produced photon state. We use Silicon Photomultiplier (SiPM) number-resolving detectors in order to observe the photon-number distribution of a PDC source, and show its dependence on the number of collected modes. Additionally, we show how the stimulated emission of photons and the partition of photons into several modes determine the overall photon number. We present a novel analytical model for the optical crosstalk effect in SiPM detectors, and use it to analyze the results. PMID:22330466

Dovrat, L; Bakstein, M; Istrati, D; Shaham, A; Eisenberg, H S

2012-01-30

56

Statistical error in particle simulations of low mach number flows  

SciTech Connect

We present predictions for the statistical error due to finite sampling in the presence of thermal fluctuations in molecular simulation algorithms. The expressions are derived using equilibrium statistical mechanics. The results show that the number of samples needed to adequately resolve the flowfield scales as the inverse square of the Mach number. Agreement of the theory with direct Monte Carlo simulations shows that the use of equilibrium theory is justified.

Hadjiconstantinou, N G; Garcia, A L

2000-11-13

57

Photon number amplification/duplication through parametric conversion  

NASA Technical Reports Server (NTRS)

The performance of parametric conversion in achieving number amplification and duplication is analyzed. It is shown that the effective maximum gains G(sub *) remain well below their integer ideal values, even for large signals. Correspondingly, one has output Fano factors F(sub *) which are increasing functions of the input photon number. On the other hand, in the inverse (deamplifier/recombiner) operating mode quasi-ideal gains G(sub *) and small factors F(sub *) approximately equal to 10 percent are obtained. Output noise and non-ideal gains are ascribed to spontaneous parametric emission.

Dariano, G. M.; Macchiavello, C.; Paris, M.

1993-01-01

58

Predicting landfalling hurricane numbers from basin hurricane numbers: basic statistical analysis  

E-print Network

One possible method for predicting landfalling hurricane numbers is to first predict the number of hurricanes in the basin and then convert that prediction to a prediction of landfalling hurricane numbers using an estimated proportion. Should this work better than just predicting landfalling hurricane numbers directly? We perform a basic statistical analysis of this question in the context of a simple abstract model.

Laepple, T; Penzer, J; Bellone, E; Nzerem, K; Laepple, Thomas; Jewson, Stephen; Penzer, Jeremy; Bellone, Enrica; Nzerem, Kechi

2007-01-01

59

On-chip, photon-number-resolving, telecommunication-band detectors for scalable photonic information processing  

SciTech Connect

Integration is currently the only feasible route toward scalable photonic quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip detection will be critical to such devices. We demonstrate an integrated photon-number-resolving detector, operating in the telecom band at 1550 nm, employing an evanescently coupled design that allows it to be placed at arbitrary locations within a planar circuit. Up to five photons are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The detection efficiency is 7.2{+-}0.5 %. The polarization sensitivity of the detector is also demonstrated. Detailed modeling of device designs shows a clear and feasible route to reaching high detection efficiencies.

Gerrits, Thomas; Lita, Adriana E.; Calkins, Brice; Tomlin, Nathan A.; Fox, Anna E.; Linares, Antia Lamas; Mirin, Richard P.; Nam, Sae Woo [National Institute of Standards and Technology, Boulder, Colorado, 80305 (United States); Thomas-Peter, Nicholas; Metcalf, Benjamin J.; Spring, Justin B.; Langford, Nathan K.; Walmsley, Ian A. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Gates, James C.; Smith, Peter G. R. [Optoelectronics Research Centre, University of Southampton, Highfield SO17 1BJ (United Kingdom)

2011-12-15

60

Enhancement of Photon Number Reflected by the Relativistic Flying Mirror  

SciTech Connect

Laser light reflection by a relativistically moving electron density modulation (flying mirror) in a wake wave generated in a plasma by a high intensity laser pulse is investigated experimentally. A counterpropagating laser pulse is reflected and upshifted in frequency with a multiplication factor of 37-66, corresponding to the extreme ultraviolet wavelength. The demonstrated flying mirror reflectivity (from 3x10{sup -6} to 2x10{sup -5}, and from 1.3x10{sup -4} to 0.6x10{sup -3}, for the photon number and pulse energy, respectively) is close to the theoretical estimate for the parameters of the experiment.

Kando, M.; Pirozhkov, A. S.; Kawase, K.; Esirkepov, T. Zh.; Fukuda, Y.; Kiriyama, H.; Okada, H.; Daito, I.; Kameshima, T.; Hayashi, Y.; Kotaki, H.; Mori, M.; Koga, J. K.; Daido, H.; Faenov, A. Ya.; Pikuz, T.; Ma, J.; Chen, L.-M.; Kawachi, T.; Kato, Y. [Advanced Photon Research Center, JAEA, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215 (Japan)

2009-12-04

61

Near-IR photon number resolving detector design  

NASA Astrophysics Data System (ADS)

Photon-Number-Resolving-Detection (PNRD) capability is crucial for many Quantum-Information (QI) applications, e.g. for Coherent-State-Quantum-Computing, Linear-Optics-Quantum-Computing. In Quantum-Key-Distribution and Quantum-Secret-Sharing over 1310/1550 nm fiber, two other important, defense and information security related, QI applications, it's crucial for the information transmission security to guarantee that the information carriers (photons) are single. Thus a PNRD can provide an additional security level against eavesdropping. Currently, there are at least a couple of promising PNRD technologies in the Near-Infrared, but all of them require cryogenic cooling. Thus a compact, portable PNRD, based on commercial Avalanche-Photo-Diodes (APDs), could be a very useful instrument for many QI experiments. For an APD-based PNRD, it is crucial to measure the APD-current in the beginning of the avalanche. Thus an efficient cancellation of the APD capacitive spikes is a necessary condition for the very weak APD current measurement. The detector's principle is based on two commercial, pair-matched InGaAs/InP APDs, connected in series. It leads to a great cancelation of the capacitive spikes caused by the narrow (300 ps), differential gate-pulses of maximum 4V amplitude assuming that both pulses are perfectly matched in regards to their phases, amplitudes, and shapes. The cancellation scheme could be used for other APD-technologies, e.g. Silicon, extending the detection spectrum from visible to NIR. The design distinguishes itself from other, APD-based, schemes by its scalability feature and its computer controlled cancellation of the capacitive spikes. Furthermore, both APDs could be equally used for the detection purpose, which opens a possibility for the odd-even photon number parity detection.

Bogdanski, Jan; Huntington, Elanor H.

2013-05-01

62

Simulations of photon detection in silicon photomultiplier number-resolving detectors  

NASA Astrophysics Data System (ADS)

Number-resolving single-photon detectors are essential for the implementation of numerous innovative quantum information schemes. While several number-discriminating techniques have previously been presented, the silicon photo-multiplier (SiPM) detector is a promising candidate owing to its rather simple integration in optical setups. On the other hand, the photon statistics obtained with the SiPM detector suffer from inaccuracies due to inherent distortions which are dependent on the geometrical properties of the SiPM. We simulated the detection process in an SiPM detector and studied these distortions. We used the results of the simulation to interpret the experimental data and to study the limits in which available models prevail.

Dovrat, L.; Bakstein, M.; Istrati, D.; Eisenberg, H. S.

2012-02-01

63

Photon-number distributions of twin beams generated in spontaneous parametric down-conversion and measured by an intensified CCD camera  

NASA Astrophysics Data System (ADS)

The measurement of photon-number statistics of fields composed of photon pairs, generated in spontaneous parametric down-conversion and detected by an intensified charge-coupled device (iCCD) camera, is described. Final quantum detection efficiencies, electronic noises, finite numbers of detector pixels, transverse intensity spatial profiles of the detected beams, as well as losses of single photons from a pair are taken into account in a developed general theory of photon-number detection. The measured data provided by an iCCD camera with single-photon detection sensitivity are analyzed along the developed theory. Joint signal-idler photon-number distributions are recovered using the reconstruction method based on the principle of maximum likelihood. The range of applicability of the method is discussed. The reconstructed joint signal-idler photon-number distribution is compared with that obtained by a method that uses superposition of signal and noise and minimizes photoelectron entropy. Statistics of the reconstructed fields are identified to be multimode Gaussian. Elements of the measured as well as the reconstructed joint signal-idler photon-number distributions violate classical inequalities. Sub-shot-noise correlations in the difference of the signal and idler photon numbers as well as partial suppression of odd elements in the distribution of the sum of signal and idler photon numbers are observed.

Pe?ina, Jan, Jr.; Hamar, Martin; Michálek, Václav; Haderka, Ond?ej

2012-02-01

64

Photon-number distributions of twin beams generated in spontaneous parametric down-conversion and measured by an intensified CCD camera  

E-print Network

The measurement of photon-number statistics of fields composed of photon pairs, generated in spontaneous parametric down-conversion and detected by an intensified CCD camera is described. Final quantum detection efficiencies, electronic noises, finite numbers of detector pixels, transverse intensity spatial profiles of the detected beams as well as losses of single photons from a pair are taken into account in a developed general theory of photon-number detection. The measured data provided by an iCCD camera with single-photon detection sensitivity are analyzed along the developed theory. Joint signal-idler photon-number distributions are recovered using the reconstruction method based on the principle of maximum likelihood. The range of applicability of the method is discussed. The reconstructed joint signal-idler photon-number distribution is compared with that obtained by a method that uses superposition of signal and noise and minimizes photoelectron entropy. Statistics of the reconstructed fields are identified to be multi-mode Gaussian. Elements of the measured as well as the reconstructed joint signal-idler photon-number distributions violate classical inequalities. Sub-shot-noise correlations in the difference of the signal and idler photon numbers as well as partial suppression of odd elements in the distribution of the sum of signal and idler photon numbers are observed.

Jan Perina Jr; Ondrej Haderka; Martin Hamar; Vaclav Michalek

2012-02-07

65

Submillimeter Number Counts from Statistical Analysis of BLAST Maps  

Microsoft Academic Search

We describe the application of a statistical method to estimate submillimeter galaxy number counts from confusion-limited observations by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). Our method is based on a maximum likelihood fit to the pixel histogram, sometimes called \\

Guillaume Patanchon; Peter A. R. Ade; James J. Bock; Edward L. Chapin; Mark J. Devlin; Simon R. Dicker; Matthew Griffin; Joshua O. Gundersen; Mark Halpern; Peter C. Hargrave; David H. Hughes; Jeff Klein; Gaelen Marsden; Philip Mauskopf; Lorenzo Moncelsi; Calvin B. Netterfield; Luca Olmi; Enzo Pascale; Marie Rex; Douglas Scott; Christopher Semisch; Nicholas Thomas; Matthew D. P. Truch; Carole Tucker; Gregory S. Tucker; Marco P. Viero; Donald V. Wiebe

2009-01-01

66

Intensive statistical complexity measure of pseudorandom number generators  

NASA Astrophysics Data System (ADS)

A Statistical Complexity measure has been recently proposed to quantify the performance of chaotic Pseudorandom number generators (PRNG) (Physica A 354 (2005) 281). Here we revisit this quantifier and introduce two important improvements: (i) consideration of an intensive statistical complexity (Physica A 334 (2004) 119), and (ii) following the prescription of Brand and Pompe (Phys. Rev. Lett. 88 (2002) 174102-1) in evaluating the probability distribution associated with the PRNG. The ensuing new measure is applied to a very well-tested PRNG advanced by Marsaglia.

Larrondo, H. A.; González, C. M.; Martín, M. T.; Plastino, A.; Rosso, O. A.

2005-10-01

67

Photon-number-solving Decoy State Quantum Key Distribution  

E-print Network

In this paper, a photon-number-resolving decoy state quantum key distribution scheme is presented based on recent experimental advancements. A new upper bound on the fraction of counts caused by multiphoton pulses is given. This upper bound is independent of intensity of the decoy source, so that both the signal pulses and the decoy pulses can be used to generate the raw key after verified the security of the communication. This upper bound is also the lower bound on the fraction of counts caused by multiphoton pulses as long as faint coherent sources and high lossy channels are used. We show that Eve's coherent multiphoton pulse (CMP) attack is more efficient than symmetric individual (SI) attack when quantum bit error rate is small, so that CMP attack should be considered to ensure the security of the final key. finally, optimal intensity of laser source is presented which provides 23.9 km increase in the transmission distance. 03.67.Dd

Qing-yu Cai; Yong-gang Tan

2005-08-13

68

Simulating quantum statistics with entangled photons: a continuous transition from bosons to fermions  

E-print Network

In contrast to classical physics, quantum mechanics divides particles into two classes-bosons and fermions-whose exchange statistics dictate the dynamics of systems at a fundamental level. In two dimensions quasi-particles known as 'anyons' exhibit fractional exchange statistics intermediate between these two classes. The ability to simulate and observe behaviour associated to fundamentally different quantum particles is important for simulating complex quantum systems. Here we use the symmetry and quantum correlations of entangled photons subjected to multiple copies of a quantum process to directly simulate quantum interference of fermions, bosons and a continuum of fractional behaviour exhibited by anyons. We observe an average similarity of 93.6\\pm0.2% between an ideal model and experimental observation. The approach generalises to an arbitrary number of particles and is independent of the statistics of the particles used, indicating application with other quantum systems and large scale application.

Jonathan C. F. Matthews; Konstantinos Poulios; Jasmin D. A. Meinecke; Alberto Politi; Alberto Peruzzo; Nur Ismail; Kerstin Wörhoff; Mark G. Thompson; Jeremy L. O'Brien

2011-06-06

69

Passive scheme with a photon-number-resolving detector for monitoring the untrusted source in a plug-and-play quantum-key-distribution system  

Microsoft Academic Search

A passive scheme with a beam splitter and a photon-number-resolving (PNR) detector is proposed to verify the photon statistics of an untrusted source in a plug-and-play quantum-key-distribution system by applying a three-intensity decoy-state protocol. The practical issues due to statistical fluctuation and detection noise are analyzed. The simulation results show that the scheme can work efficiently when the total number

Bingjie Xu; Xiang Peng; Hong Guo

2010-01-01

70

Photon statistics of intense entangled photon pulses This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-print Network

Photon statistics of intense entangled photon pulses This article has been downloaded from. Phys. B: At. Mol. Opt. Phys. 46 (2013) 175502 (11pp) doi:10.1088/0953-4075/46/17/175502 Photon statistics of intense entangled photon pulses Frank Schlawin and Shaul Mukamel Department of Chemistry

Mukamel, Shaul

71

Time-dependent photon number discrimination of InGaAs/InP avalanche photodiode single-photon detector.  

PubMed

We investigated the photon-number-resolving (PNR) performance of the InGaAs/InP avalanche photodiode (APD) as a function of the electric gate width and the photon arrival time. The optimal electric gate width was around 1 ns for PNR measurements in our experiment, which provided a PNR capability up to three photons per pulse when the detection efficiency was ~20%. And the dependence of the PNR performance on the arrival time of the photons showed that the photon number could be better resolved if the photons arrived on the rising edge of the electric gate than on the falling edge. In addition, we found that with the increase of the electric gate width, PNR performance got worse. The observation would be helpful for improving the PNR performance of the InGaAs/InP APD in the gated mode. PMID:21221161

Jian, Yi; Wu, E; Chen, Xiuliang; Wu, Guang; Zeng, Heping

2011-01-01

72

Direct observation of the degree of correlations using photon-number-resolving detectors  

NASA Astrophysics Data System (ADS)

Optical parametric down-conversion is a common source for the generation of nonclassical correlated photonic states. Using a parametric down-conversion source and photon-number-resolving detectors, we measure the two-mode photon-number distribution of up to 10 photons for different degrees of correlation. The degree of correlation is controlled by collecting different spatial and spectral single modes for each polarization and varying the amount of spectral and spatial overlap between them. Clear evidence for photon-number correlations is presented despite detector imperfections such as low detection efficiency and other distorting effects. Two criteria, derived directly from the raw data, are shown to be good measures for the degree of correlation. Additionally, using a fitting technique, we find a connection between the measured photon-number distribution and the degree of correlation of the reconstructed original two-mode state. These observations are only possible as a result of the detection of high photon number events.

Dovrat, L.; Bakstein, M.; Istrati, D.; Megidish, E.; Halevy, A.; Cohen, L.; Eisenberg, H. S.

2013-05-01

73

Measurement of two-mode squeezing with photon number resolving multi-pixel detectors  

E-print Network

The measurement of the two-mode squeezed vacuum generated in an optical parametric amplifier (OPA) was performed with photon number resolving Multi-Pixel Photon Counters (MPPCs). Implementation of the MPPCs allows for the observation of noise reduction in a broad dynamic range of the OPA gain, which is inaccessible with standard single photon avalanche photodetectors.

Dmitry A. Kalashnikov; Si-Hui Tan; Timur Sh. Iskhakov; Maria V. Chekhova; Leonid A. Krivitsky

2012-05-14

74

Statistical distributions of earthquake numbers: consequence of branching process  

NASA Astrophysics Data System (ADS)

We discuss various statistical distributions of earthquake numbers. Previously, we derived several discrete distributions to describe earthquake numbers for the branching model of earthquake occurrence: these distributions are the Poisson, geometric, logarithmic and the negative binomial (NBD). The theoretical model is the `birth and immigration' population process. The first three distributions above can be considered special cases of the NBD. In particular, a point branching process along the magnitude (or log seismic moment) axis with independent events (immigrants) explains the magnitude/moment-frequency relation and the NBD of earthquake counts in large time/space windows, as well as the dependence of the NBD parameters on the magnitude threshold (magnitude of an earthquake catalogue completeness). We discuss applying these distributions, especially the NBD, to approximate event numbers in earthquake catalogues. There are many different representations of the NBD. Most can be traced either to the Pascal distribution or to the mixture of the Poisson distribution with the gamma law. We discuss advantages and drawbacks of both representations for statistical analysis of earthquake catalogues. We also consider applying the NBD to earthquake forecasts and describe the limits of the application for the given equations. In contrast to the one-parameter Poisson distribution so widely used to describe earthquake occurrence, the NBD has two parameters. The second parameter can be used to characterize clustering or overdispersion of a process. We determine the parameter values and their uncertainties for several local and global catalogues, and their subdivisions in various time intervals, magnitude thresholds, spatial windows, and tectonic categories. The theoretical model of how the clustering parameter depends on the corner (maximum) magnitude can be used to predict future earthquake number distribution in regions where very large earthquakes have not yet occurred.

Kagan, Yan Y.

2010-03-01

75

Advanced Photon Source research: Volume 1, Number 1, April 1998  

SciTech Connect

The following articles are included in this publication: (1) The Advanced Photon Source: A Brief Overview; (2) MAD Analysis of FHIT at the Structural Biology Center; (3) Advances in High-Energy-Resolution X-ray Scattering at Beamline 3-ID; (4) X-ray Imaging and Microspectroscopy of the Mycorrhyizal Fungus-Plant Symbiosis; (5) Measurement and Control of Particle-beam Trajectories in the Advanced Photon Storage Ring; (6) Beam Acceleration and Storage at the Advanced Photon Source; and (7) Experimental Facilities Operations and Current Status.

NONE

1998-04-01

76

Joint statistics of photon path length and cloud optical depth: Case studies  

Microsoft Academic Search

We show the joint statistics of photon path length and cloud optical depth for cloudy sky cases observed at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site between September and December 1997. The photon path lengths are retrieved from moderate resolution oxygen A-band observations taken by a rotating shadow band spectroradiometer (RSS). For high optical depth cloud cases,

Qilong Min; Lee C. Harrison; Eugene E. Clothiaux

2001-01-01

77

AN AUTOMATED STATISTICAL ANALYSIS APPROACH TO NOISE REDUCTION FOR PHOTON-COUNTING LIDAR SYSTEMS  

E-print Network

AN AUTOMATED STATISTICAL ANALYSIS APPROACH TO NOISE REDUCTION FOR PHOTON-COUNTING LIDAR SYSTEMS K, Rochester, NY, USA ABSTRACT Satellite-based and airborne lidar instrumentation has been demonstrated the Multiple Altimeter Beam Experimental Lidar (MABEL) instrument, an experimental photon-counting lidar

Kerekes, John

78

Quantum Statistics of One-Photon Interaction of Light With Matter  

Microsoft Academic Search

Quantum statistics of one-photon interaction of light with matter is investigated. It is found that in general the density operator changes. For a chaotic field, however, the density operator changes only in a trivial way.

Naresh Chandra; Hari Prakash

1969-01-01

79

Submillimeter Number Counts From Statistical Analysis of BLAST Maps  

E-print Network

We describe the application of a statistical method to estimate submillimeter galaxy number counts from the confusion limited observations of the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). Our method is based on a maximum likelihood fit to the pixel histogram, sometimes called 'P(D)', an approach which has been used before to probe faint counts, the difference being that here we advocate its use even for sources with relatively high signal-to-noise ratios. This method has an advantage over standard techniques of source extraction in providing an unbiased estimate of the counts from the bright end down to flux densities well below the confusion limit. We specifically analyse BLAST observations of a roughly 10 sq. deg map centered on the Great Observatories Origins Deep Survey South field. We provide estimates of number counts at the three BLAST wavelengths, 250, 350, and 500 microns, instead of counting sources in flux bins we estimate the counts at several flux density nodes connected with ...

Patanchon, Guillaume; Bock, James J; Chapin, Edward L; Devlin, Mark J; Dicker, Simon R; Griffin, Matthew; Gundersen, Joshua O; Halpern, Mark; Hargrave, Peter C; Hughes, David H; Klein, Jeff; Marsden, Gaelen; Mauskopf, Philip; Moncelsi, Lorenzo; Netterfield, Calvin B; Olmi, Luca; Pascale, Enzo; Rex, Marie; Scott, Douglas; Semisch, Christopher; Thomas, Nicholas; Truch, Matthew D P; Tucker, Carole; Tucker, Gregory S; Viero, Marco P; Wiebe, Donald V

2009-01-01

80

Biexciton quantum yield of single semiconductor nanocrystals from photon statistics  

PubMed Central

Biexciton properties strongly affect the usability of a light emitter in quantum photon sources and lasers but are difficult to measure for single fluorophores at room temperature due to luminescence intermittency and bleaching at the high excitation fluences usually required. Here, we observe the biexciton (BX) to exciton (X) to ground photoluminescence cascade of single colloidal semiconductor nanocrystals (NCs) under weak excitation in a g(2) photon correlation measurement and show that the normalized amplitude of the cascade feature is equal to the ratio of the BX to X fluorescence quantum yields. This imposes a limit on the attainable depth of photon antibunching and provides a robust means to study single emitter biexciton physics. In NC samples, we show that the BX quantum yield is considerably inhomogeneous, consistent with the defect sensitivity expected of the Auger nonradiative recombination mechanism. The method can be extended to study X,BX spectral and polarization correlations. PMID:21288042

Nair, Gautham; Zhao, Jing; Bawendi, Moungi G

2012-01-01

81

Photon statistics of multimode even and odd coherent light  

E-print Network

The even and odd coherent states are generalized for multimode case. The explicit forms for the photon distribution, Q-function and Wigner function are derived. In particular, it is shown that for two-mode case there exist strong correlations between these modes, under certain conditions, which are responsible for two-mode squeezing in case of even coherent states

Nadeem A. Ansari; V. I. Man'ko

1993-08-07

82

Statistics for Geography Teachers: Topics in Geography, Number 2.  

ERIC Educational Resources Information Center

This publication is designed to provide geography teachers with useful statistical information. It presents tables, maps, graphs, diagrams, and explanations of statistical data in 24 areas. The areas in which statistics are given are conversions, measurement, astronomy, time, daylight, twilight, latitude and longitude as distance, the relationship…

National Council for Geographic Education.

83

SUBMILLIMETER NUMBER COUNTS FROM STATISTICAL ANALYSIS OF BLAST MAPS  

SciTech Connect

We describe the application of a statistical method to estimate submillimeter galaxy number counts from confusion-limited observations by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). Our method is based on a maximum likelihood fit to the pixel histogram, sometimes called 'P(D)', an approach which has been used before to probe faint counts, the difference being that here we advocate its use even for sources with relatively high signal-to-noise ratios. This method has an advantage over standard techniques of source extraction in providing an unbiased estimate of the counts from the bright end down to flux densities well below the confusion limit. We specifically analyze BLAST observations of a roughly 10 deg{sup 2} map centered on the Great Observatories Origins Deep Survey South field. We provide estimates of number counts at the three BLAST wavelengths 250, 350, and 500 mum; instead of counting sources in flux bins we estimate the counts at several flux density nodes connected with power laws. We observe a generally very steep slope for the counts of about -3.7 at 250 mum, and -4.5 at 350 and 500 mum, over the range approx0.02-0.5 Jy, breaking to a shallower slope below about 0.015 Jy at all three wavelengths. We also describe how to estimate the uncertainties and correlations in this method so that the results can be used for model-fitting. This method should be well suited for analysis of data from the Herschel satellite.

Patanchon, Guillaume [Universite Paris Diderot, Laboratoire APC, 10, rue Alice Domon et Leonie Duquet 75205 Paris (France); Ade, Peter A. R.; Griffin, Matthew; Hargrave, Peter C.; Mauskopf, Philip; Moncelsi, Lorenzo; Pascale, Enzo [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Bock, James J. [School of Physics and Astronomy, Cardiff University, 5 The Parade, Cardiff, CF24 3AA (United Kingdom); Chapin, Edward L.; Halpern, Mark; Marsden, Gaelen; Scott, Douglas [Jet Propulsion Laboratory, Pasadena, CA 91109-8099 (United States); Devlin, Mark J.; Dicker, Simon R.; Klein, Jeff; Rex, Marie [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Gundersen, Joshua O. [Department of Physics, University of Miami, 1320 Campo Sano Drive, Coral Gables, FL 33146 (United States); Hughes, David H. [Instituto Nacional de AstrofIsica Optica y Electronica (INAOE), Aptdo. Postal 51 y 72000 Puebla (Mexico); Netterfield, Calvin B. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street Toronto, ON M5S 3H4 (Canada); Olmi, Luca, E-mail: patanchon@apc.univ-paris-diderot.f [Physics Department, University of Puerto Rico, Rio Piedras Campus, P.O. Box 23343, UPR Station, San Juan (Puerto Rico)

2009-12-20

84

Multi-bit quantum random number generation by measuring positions of arrival photons.  

PubMed

We report upon the realization of a novel multi-bit optical quantum random number generator by continuously measuring the arrival positions of photon emitted from a LED using MCP-based WSA photon counting imaging detector. A spatial encoding method is proposed to extract multi-bits random number from the position coordinates of each detected photon. The randomness of bits sequence relies on the intrinsic randomness of the quantum physical processes of photonic emission and subsequent photoelectric conversion. A prototype has been built and the random bit generation rate could reach 8 Mbit/s, with random bit generation efficiency of 16 bits per detected photon. FPGA implementation of Huffman coding is proposed to reduce the bias of raw extracted random bits. The random numbers passed all tests for physical random number generator. PMID:25362380

Yan, Qiurong; Zhao, Baosheng; Liao, Qinghong; Zhou, Nanrun

2014-10-01

85

Multi-bit quantum random number generation by measuring positions of arrival photons  

NASA Astrophysics Data System (ADS)

We report upon the realization of a novel multi-bit optical quantum random number generator by continuously measuring the arrival positions of photon emitted from a LED using MCP-based WSA photon counting imaging detector. A spatial encoding method is proposed to extract multi-bits random number from the position coordinates of each detected photon. The randomness of bits sequence relies on the intrinsic randomness of the quantum physical processes of photonic emission and subsequent photoelectric conversion. A prototype has been built and the random bit generation rate could reach 8 Mbit/s, with random bit generation efficiency of 16 bits per detected photon. FPGA implementation of Huffman coding is proposed to reduce the bias of raw extracted random bits. The random numbers passed all tests for physical random number generator.

Yan, Qiurong; Zhao, Baosheng; Liao, Qinghong; Zhou, Nanrun

2014-10-01

86

Streamline segment statistics of premixed flames with nonunity Lewis numbers.  

PubMed

The interaction of flame and surrounding fluid motion is of central importance in the fundamental understanding of turbulent combustion. It is demonstrated here that this interaction can be represented using streamline segment analysis, which was previously applied in nonreactive turbulence. The present work focuses on the effects of the global Lewis number (Le) on streamline segment statistics in premixed flames in the thin-reaction-zones regime. A direct numerical simulation database of freely propagating thin-reaction-zones regime flames with Le ranging from 0.34 to 1.2 is used to demonstrate that Le has significant influences on the characteristic features of the streamline segment, such as the curve length, the difference in the velocity magnitude at two extremal points, and their correlations with the local flame curvature. The strengthenings of the dilatation rate, flame normal acceleration, and flame-generated turbulence with decreasing Le are principally responsible for these observed effects. An expression for the probability density function (pdf) of the streamline segment length, originally developed for nonreacting turbulent flows, captures the qualitative behavior for turbulent premixed flames in the thin-reaction-zones regime for a wide range of Le values. The joint pdfs between the streamline length and the difference in the velocity magnitude at two extremal points for both unweighted and density-weighted velocity vectors are analyzed and compared. Detailed explanations are provided for the observed differences in the topological behaviors of the streamline segment in response to the global Le. PMID:24730945

Chakraborty, Nilanjan; Wang, Lipo; Klein, Markus

2014-03-01

87

Statistical detection and imaging of objects hidden in turbid media using ballistic photons  

E-print Network

Statistical detection and imaging of objects hidden in turbid media using ballistic photons Sina-pixel statistical tests for detecting objects hidden in turbid media. To improve the detection rate High-resolution imaging and detection of objects hid- den in a turbid (scattering) medium have long

88

The Effect of Partial Coherence on the Statistics of Single-Photon Pulses Propagating in the Atmosphere  

E-print Network

The photon density operator function is used to describe the propagation of single-photon pulses through a turbulent atmosphere. The effects of statistical properties of photon source and the effects of a random phase screen on the variance of photon counting are studied. A procedure for reducing the total noise is discussed. The physical mechanisms responsible for this reduction are explained.

G. P. Berman; A. A. Chumak

2007-02-26

89

Adaptive Quantum Nondemolition Measurement of a Photon Number  

NASA Astrophysics Data System (ADS)

In many quantum measurements, information is acquired incrementally by the successive interaction of meters with the measured system. Adaptive measurements minimize the use of resources (meters) by adjusting the measurement settings according to available information. We demonstrate an adaptive measurement for nondestructive photon counting in a cavity, based on Ramsey interferometry for Rydberg atoms interacting with the field. Tuning the interferometer in real time, we speed up the measurement by up to 45%. Such adaptive methods are promising for quantum metrology, state preparation, and feedback.

Peaudecerf, B.; Rybarczyk, T.; Gerlich, S.; Gleyzes, S.; Raimond, J. M.; Haroche, S.; Dotsenko, I.; Brune, M.

2014-02-01

90

Talking Numbers: How Statistics Tell us Society's Story  

NSDL National Science Digital Library

Instructors at the Pensacola Junior College use this course to explain how social scientists use statistics to understand and explain theoretical concepts. Sociologists provide a cultural context for data and then illustrate how statistical equations use seemingly irrelevant mathematical concepts to measure and compare the behavior and trends of groups of people according to major categories: gender, race, class, religion, etc. Students can then understand how such statistical concepts are essential for quantifying and theorizing about society at large. Students and instructors can both explore this class, its syllabus, and the pertinent reading lists.

Shackelford, Monisa; Spencer, Sharon J.

2008-05-05

91

Effect of Background Noise on the Photon Statistics of Triggered Single Molecules  

NASA Astrophysics Data System (ADS)

We theoretically derive exact expressions for Mandel's Q parameter of the triggered single molecular source, which is inferred from the probabilities PRS(n) using the record of each photon detection event based on Hanbury Brown and Twiss detection. The real triggered source is recognized as an ideal single photon source with a Poissonian statistics background. How to decrease the background and to increase the efficiency are discussed. It is established that the sub-Poissonian statistics formation can be determined by comparing the measured QRS of the real single triggered molecular with QC of the Poissonian source containing the same mean photons. By this method, we also give an efficient way to measure signal-to-background ratios of triggered single photons.

Xiao, Lian-Tuan; Zhao, Yan-Ting; Huang, Tao; Zhao, Jian-Ming; Yin, Wang-Bao; Jia, Suo-Tang

2004-03-01

92

Crunching Numbers: What Cancer Screening Statistics Really Tell Us  

Cancer.gov

Cancer screening studies have shown that more screening does not necessarily translate into fewer cancer deaths. This article explains how to interpret the statistics used to describe the results of screening studies.

93

Sub- and super-Poissonian photon statistics of single-molecule fluorescence blinking  

SciTech Connect

An analysis of intermittent fluorescence is presented for a single molecule driven by a continuous-wave laser field. The interruptions of fluorescence are caused by transition of the molecule to a triplet state. A method previously developed to calculate photon distribution for continuous-wave fluorescence is applied to analyze photon statistics of fluorescence blinking. The probability w{sub N}(T) of counting N photons over a time interval T is derived for intermittent fluorescence. The photons counted over relatively short intervals are found to have a sub-Poissonian (narrower than Poisson) distribution. The photon distribution over intervals longer than the mean off time has a complicated form with two maxima; i.e., a super-Poissonian (wider than Poisson) distribution is obtained.

Osad'ko, I. S. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)], E-mail: osadko@sci.lebedev.ru

2007-06-15

94

Schmidt number for X-entanglement of photon pairs  

NASA Astrophysics Data System (ADS)

We calculate the Schmidt number for a two-dimensional model of the nonfactorable spatiotemporal wave-function of biphotons produced in type-I spontaneous parametric down-conversion with degenerate and collinear phase- matching taking into consideration a major part of the broad spectral and angular bandwidth of the down- converted light. We derive an analytical expression for the Schmidt number as a function of the filter bandwidth in the limit of spectrally narrow pump.

Horoshko, D. B.; Patera, G.; Gatti, A.; Kolobov, M. I.

2012-06-01

95

Nonclassical correlations between photon number and quadrature components of the light field  

E-print Network

Finite resolution quantum nondemolition (QND) measurements allow a determination of light field properties while preserving some of the original quantum coherence of the input state. It is thus possible to measure correlations between the photon number and a quadrature component of the same light field mode. Nonclassical features emerge as photon number quantization is resolved. In particular, a strong anti-correlation of quantization and coherence is observable in QND measurements of photon number, and a correlation between measurement induced quantum jumps and quadrature component measurement results is obtained in QND measurements of quadrature fluctuations in the photon vacuum. Such nonclassical correlations represent fundamental quantum properties of the light field and may provide new insights into the nature of quantization itself.

Holger F. Hofmann

2000-04-19

96

Canadian Statistical Review. Volume 53, Number 7, July 1978.  

ERIC Educational Resources Information Center

Information on Canadian social and economic trends is presented in this statistical review. Advance information on national income and expenditure accounts for the first quarter of 1978 is provided. Characteristics of full-time university teachers from 1956-57 to 1977-78 are detailed in tables that recount such developments as the nearly six-fold…

von Zur-Muehlen, Max

1978-01-01

97

USA by Numbers: A Statistical Portrait of the United States.  

ERIC Educational Resources Information Center

This book presents demographic data about a variety of U.S. public policies, social problems, and environmental issues. The issues and problems that the statistics illustrate (such as overflowing garbage dumps, homelessness, child poverty, and smog and water pollution) are connected with, and the consequences of, the expanding U.S. population. The…

Weber, Susan, Ed.

98

Measurement of Photon Statistics with Live Photoreceptor Cells  

NASA Astrophysics Data System (ADS)

We analyzed the electrophysiological response of an isolated rod photoreceptor of Xenopus laevis under stimulation by coherent and pseudothermal light sources. Using the suction-electrode technique for single cell recordings and a fiber optics setup for light delivery allowed measurements of the major statistical characteristics of the rod response. The results indicate differences in average responses of rod cells to coherent and pseudothermal light of the same intensity and also differences in signal-to-noise ratios and second-order intensity correlation functions. These findings should be relevant for interdisciplinary studies seeking applications of quantum optics in biology.

Sim, Nigel; Cheng, Mei Fun; Bessarab, Dmitri; Jones, C. Michael; Krivitsky, Leonid A.

2012-09-01

99

Statistical method for resolving the photon-photoelectron-counting inversion problem  

SciTech Connect

A statistical inversion method is proposed for the photon-photoelectron-counting statistics in quantum key distribution experiment. With the statistical viewpoint, this problem is equivalent to the parameter estimation for an infinite binomial mixture model. The coarse-graining idea and Bayesian methods are applied to deal with this ill-posed problem, which is a good simple example to show the successful application of the statistical methods to the inverse problem. Numerical results show the applicability of the proposed strategy. The coarse-graining idea for the infinite mixture models should be general to be used in the future.

Wu Jinlong [LMAM and School of Mathematical Sciences, Peking University, Beijing 100871 (China); Li Tiejun, E-mail: tieli@pku.edu.c [LMAM and School of Mathematical Sciences, Peking University, Beijing 100871 (China); Peng, Xiang, E-mail: xiangpeng@pku.edu.c [CREAM Group, State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China); Guo Hong, E-mail: hongguo@pku.edu.c [CREAM Group, State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)

2011-02-01

100

Statistical characteristics of free falling films at high reynolds numbers  

Microsoft Academic Search

The characteristics of films flowing inside a vertical pipe are studied experimentally. Using an accurate wire conductance technique the film thickness is measured over the Re range 509-13,090. The mean film thickness data are in good overall agreement with established relations. Extensive statistical analysis shows that film thickness fluctuations have a stochastic character. The description given by Dukler and co-workers,

T. D. KARAPANTSIOS; S. V. PARAS; A. J. KARABELAS

1989-01-01

101

Evolution of the photon statistics of light propagating through a random medium  

Microsoft Academic Search

We study the photon statistics of light propagating through a random medium such as the turbulent atmosphere by solving the differential equations for the field operators in the Heisenberg picture. The obtained solutions are used for calculation of the characteristic functions and quasi-distributions. We particularly show that the quasi-distribution related to normally ordered operators does not exist in a random

J. Perina; V. Pe?inová; R. Horák

1973-01-01

102

Beating the Abbe Diffraction Limit in Confocal Microscopy via Nonclassical Photon Statistics  

NASA Astrophysics Data System (ADS)

We experimentally demonstrate quantum enhanced resolution in confocal fluorescence microscopy exploiting the nonclassical photon statistics of single nitrogen-vacancy color centers in diamond. By developing a general model of superresolution based on the direct sampling of the kth-order autocorrelation function of the photoluminescence signal, we show the possibility to resolve, in principle, arbitrarily close emitting centers.

Gatto Monticone, D.; Katamadze, K.; Traina, P.; Moreva, E.; Forneris, J.; Ruo-Berchera, I.; Olivero, P.; Degiovanni, I. P.; Brida, G.; Genovese, M.

2014-10-01

103

Beating the Abbe Diffraction Limit in Confocal Microscopy via Nonclassical Photon Statistics.  

PubMed

We experimentally demonstrate quantum enhanced resolution in confocal fluorescence microscopy exploiting the nonclassical photon statistics of single nitrogen-vacancy color centers in diamond. By developing a general model of superresolution based on the direct sampling of the kth-order autocorrelation function of the photoluminescence signal, we show the possibility to resolve, in principle, arbitrarily close emitting centers. PMID:25325642

Gatto Monticone, D; Katamadze, K; Traina, P; Moreva, E; Forneris, J; Ruo-Berchera, I; Olivero, P; Degiovanni, I P; Brida, G; Genovese, M

2014-10-01

104

Sub-shot-noise photon-number correlation in a mesoscopic twin beam of light  

SciTech Connect

We demonstrate sub-shot-noise photon-number correlations in a (temporal) multimode mesoscopic ({approx}10{sup 3} detected photons) twin beam produced by picosecond-pulsed spontaneous nondegenerate parametric down-conversion. We have separately detected the signal and idler distributions of photons collected in twin coherence areas and found that the variance of the photon-count difference goes below the shot-noise limit by 3.25 dB. The number of temporal modes contained in the twin beam, as well as the size of the twin coherence areas, depends on the pump intensity. Our scheme is based on spontaneous down-conversion and thus does not suffer from limitations due to the finite gain of the parametric process. Twin beams are also used to demonstrate the conditional preparation of a nonclassical (sub-Poissonian) state.

Bondani, Maria [National Laboratory for Ultrafast and Ultraintense Optical Science, C.N.R.-I.N.F.M., Como (Italy); Allevi, Alessia; Andreoni, Alessandra [C.N.R.-I.N.F.M.-C.N.I.S.M., Dipartimento di Fisica e Matematica, Universita dell'Insubria, Como (Italy); Zambra, Guido [Dipartimento di Fisica e Matematica, Universita dell'Insubria, Como (Italy); Dipartimento di Fisica dell'Universita di Milano, Milan (Italy); Paris, Matteo G. A. [Dipartimento di Fisica dell'Universita di Milano, Milan (Italy)

2007-07-15

105

Super-resolving single-photon number-path-entangled state and its generation  

NASA Astrophysics Data System (ADS)

In this paper, we propose two protocols for generating super-resolving single-photon (SRSP) number-path-entangled states from general maximally number-path-entangled NOON states. It is our purpose to show that, contrary to popular belief, a field in a single-photon state can carry multifold phase information. We also show that both protocols generate the desired state with different probabilities depending on the type of detectors being used. Such SRSP number-path-entangled states preserve high resolving power but lack the requirement of a multiphoton absorbing resist, which may serve as a proof-of-principle prototype for quantum lithography in the future.

Feng, Wei; Jiang, Kebei; Lollie, Michelle L.-J.; Zubairy, M. Suhail; Dowling, Jonathan P.

2014-04-01

106

Absolute calibration of photon-number-resolving detectors with an analog output using twin beams  

E-print Network

A method for absolute calibration of a photon-number resolving detector producing analog signals as the output is developed using a twin beam. The method gives both analog-to-digital conversion parameters and quantum detection efficiency for the photon fields. Characteristics of the used twin beam are also obtained. A simplified variant of the method applicable to fields with high signal to noise ratios and suitable for more intense twin beams is suggested.

Jan Perina Jr.; Ondrej Haderka; Alessia Allevi; Maria Bondani

2014-01-23

107

Absolute calibration of photon-number-resolving detectors with an analog output using twin beams  

NASA Astrophysics Data System (ADS)

A method for absolute calibration of a photon-number resolving detector producing analog signals as the output is developed using a twin beam. The method gives both analog-to-digital conversion parameters and quantum detection efficiency for the photon fields. Characteristics of the used twin beam are also obtained. A simplified variant of the method applicable to fields with high signal to noise ratios and suitable for more intense twin beams is suggested.

Pe?ina, Jan; Haderka, Ond?ej; Allevi, Alessia; Bondani, Maria

2014-01-01

108

Highly sensitive, photon number resolving detectors mediated by phonons using $?$-doped GaAs transistors  

E-print Network

We report a photon number resolving detector using two-dimensional electron gas (2DEG) based transistors. When the photon pulses impinge on the absorption region, the generated phonons dissipate ballistically in the 2DEG toward the trench isolated nanowire transistors near the surface. The phonon-electron interaction induces a positive conductance in the transistors, resulting in a current increase. With this principle, we obtain an internal quantum efficiency for this type of detector of up to 85%.

Xiulai Xu; Hugh Baker; David A. Williams

2010-05-03

109

Sensitivity of photon-counting Kedge imaging: Dependence on atomic number and object size  

Microsoft Academic Search

The feasibility of K-edge x-ray CT imaging has been demonstrated both by simulations and by experiments performed on energy-resolved, photon-counting data. The method is based on detecting the difference in attenuation above and below the K-edge of elements with high atomic number Z measured with energy-sensitive, photon counting devices. So far, the sensitivity of this technique has been probed only

Ewald Roessl; Bernhard Brendel; Jens-Peter Schlornka; Axel Thran; Roland Proksa

2008-01-01

110

Photon Maps Photon Tracing  

E-print Network

Photon Maps Photon Tracing Simulating light propagation by shooting photons from the light sources. Photon Tracing Storing the incidences of photon's path. Implementing surface properties statistically. Russian Roulette. Photon Tracing Photon maps keep: Incidence point (in 3D). The normal at that point

Lischinski, Dani

111

Direct observation of bosonic quantum interference of surface plasmon polaritons using photon-number-resolving detectors  

NASA Astrophysics Data System (ADS)

Quantum plasmonics is a field of research combining plasmonics with quantum optics and investigates interactions between photons and metallic nanostructures. So far, it has been proven that quantum properties of single photons to excite single surface plasmon polaritons (SPPs) are preserved in the process of photon-SPP-photon mode conversion in plasmonic nanostructures, which suggests the potential application of SPPs to the quantum information processing (QIP). Recently the Hong-Ou-Mandel (HOM) interference of single SPPs was observed in a plasmonic circuitry. However, the visibility was below the classical limit (50%) due to the simultaneous excitation of distinguishable SPP modes. We employed a directional coupler based on long-range surface-plasmon-polariton waveguides (LRSPP-DC) and superconducting photon-number-resolving detectors to directly observe the bosonic quantum interference of single SPPs beyond the classical limit. In addition, we demonstrated the indistinguishability of photons that excite single SPPs is well preserved in the process of photon-SPP mode conversion.

Fujii, Go; Fukuda, Daiji; Inoue, Shuichiro

2014-08-01

112

Statistical evaluation of PACSTAT random number generation capabilities  

SciTech Connect

This report summarizes the work performed in verifying the general purpose Monte Carlo driver-program PACSTAT. The main objective of the work was to verify the performance of PACSTAT's random number generation capabilities. Secondary objectives were to document (using controlled configuration management procedures) changes made in PACSTAT at Pacific Northwest Laboratory, and to assure that PACSTAT input and output files satisfy quality assurance traceability constraints. Upon receipt of the PRIME version of the PACSTAT code from the Basalt Waste Isolation Project, Pacific Northwest Laboratory staff converted the code to run on Digital Equipment Corporation (DEC) VAXs. The modifications to PACSTAT were implemented using the WITNESS configuration management system, with the modifications themselves intended to make the code as portable as possible. Certain modifications were made to make the PACSTAT input and output files conform to quality assurance traceability constraints. 10 refs., 17 figs., 6 tabs.

Piepel, G.F.; Toland, M.R.; Harty, H.; Budden, M.J.; Bartley, C.L.

1988-05-01

113

Cavity Nonlinear Optics at Low Photon Numbers from Collective Atomic Motion  

E-print Network

We report on Kerr nonlinearity and dispersive optical bistability of a Fabry-Perot optical resonator due to the displacement of ultracold atoms trapped within. In the driven resonator, such collective motion is induced by optical forces acting upon up to $10^5$ $^{87}$Rb atoms prepared in the lowest band of a one-dimensional intracavity optical lattice. The longevity of atomic motional coherence allows for strongly nonlinear optics at extremely low cavity photon numbers, as demonstrated by the observation of both branches of optical bistability at photon numbers below unity.

Subhadeep Gupta; Kevin L. Moore; Kater W. Murch; Dan M. Stamper-Kurn

2007-06-07

114

Posting Number: 0601800 Title: Assist/Assoc/Full Professor (Applied Statistics/Biostatistics)  

E-print Network

Posting Number: 0601800 Title: Assist/Assoc/Full Professor (Applied Statistics/Biostatistics) Working Title: Assist/Assoc/Full Professor (Applied Statistics/Biostatistics) Department: Mathematical in the general area of Applied Statistics/Biostatistics. The Department is particularly interested in candidates

Shepp, Larry

115

AUSTRIAN JOURNAL OF STATISTICS Volume 32 (2003), Number 1&2, 4970  

E-print Network

, the earth's orbital eccentricity, which causes small variations of the solar energy influx. SinceAUSTRIAN JOURNAL OF STATISTICS Volume 32 (2003), Number 1&2, 49­70 Statistical Analysis the detectability of different signals, using statistical detectability measures. In the simplest setting

Mueller, Uschi

116

Statistical Handbook on Aging Americans. 1994 Edition. Statistical Handbook Series Number 5.  

ERIC Educational Resources Information Center

This statistical handbook contains 378 tables and charts illustrating the changes in the United States' aging population based on data collected during the 1990 census and several other surveys. The tables and charts are organized by topic as follows: demographics (age and sex distribution, life expectancy, race and ethnicity, geographic…

Schick, Frank L., Ed.; Schick, Renee, Ed.

117

Device-independent quantum random number generator with a photon pair source  

E-print Network

What is the most efficient way to generate random numbers device-independently using a photon pair source based on spontaneous parametric down conversion (SPDC)? We consider this question by comparing two implementations of a detection-loophole-free Bell test. In particular, we study in detail a scenario where a heralded single photon source (HSPS) is used to herald path-entangled states, i.e. entanglement between two spatial modes sharing a single photon and where non-locality is revealed using photon counting preceded by small displacement operations. We start by giving a theoretical description of such a measurement. We then show how to optimize the Bell-CHSH violation through a non-perturbative calculation, taking the main experimental imperfections into account. We finally bound the amount of randomness that can be extracted and compare it to the one obtained with the conventional scenario using photon pairs entangled e.g. in polarization and analyzed through photon counting. While the former requires higher overall detection efficiencies, it is far more efficient in terms of both the entropy per experimental run and the rate of random bit generation.

V. Caprara Vivoli; P. Sekatski; J. -D. Bancal; C. C. W. Lim; A. Martin; R. T. Thew; H. Zbinden; N. Gisin; N. Sangouard

2014-09-29

118

Statistical x-ray computed tomography imaging from photon-starved measurements  

NASA Astrophysics Data System (ADS)

Dose reduction in clinical X-ray computed tomography (CT) causes low signal-to-noise ratio (SNR) in photonsparse situations. Statistical iterative reconstruction algorithms have the advantage of retaining image quality while reducing input dosage, but they meet their limits of practicality when significant portions of the sinogram near photon starvation. The corruption of electronic noise leads to measured photon counts taking on negative values, posing a problem for the log() operation in preprocessing of data. In this paper, we propose two categories of projection correction methods: an adaptive denoising filter and Bayesian inference. The denoising filter is easy to implement and preserves local statistics, but it introduces correlation between channels and may affect image resolution. Bayesian inference is a point-wise estimation based on measurements and prior information. Both approaches help improve diagnostic image quality at dramatically reduced dosage.

Chang, Zhiqian; Zhang, Ruoqiao; Thibault, Jean-Baptiste; Sauer, Ken; Bouman, Charles

2013-03-01

119

Evolution of the photon statistics of light propagating through a random medium  

Microsoft Academic Search

The descriptions of the photon statistics of light propagating through a random medium recently proposed byDiament andTeich and byTatarski are derived as useful approximations of the exact solution of propagation of light through a random medium developed in the preceding paper; they are shown to be valid for small fluctuations of the permittivity of the random medium. Moreover, it is

J. Perina; V. Pe?inová; R. Horák

1973-01-01

120

Statistical evaluation of photon count rate data for nanoscale particle measurement in wastewaters.  

PubMed

The dynamic light scattering (DLS) technique can detect the concentration and size distribution of nanoscale particles in aqueous solutions by analyzing photon interactions. This study evaluated the applicability of using photon count rate data from DLS analyses for measuring levels of biogenic and manufactured nanoscale particles in wastewater. Statistical evaluations were performed using secondary wastewater effluent and a Malvern Zetasizer. Dynamic light scattering analyses were performed equally by two analysts over a period of two days using five dilutions and twelve replicates for each dilution. Linearity evaluation using the sixty sample analysis yielded a regression coefficient R(2) = 0.959. The accuracy analysis for various dilutions indicated a recovery of 100 ± 6%. Precision analyses indicated low variance coefficients for the impact of analysts, days, and within sample error. The variation by analysts was apparent only in the most diluted sample (intermediate precision ~12%), where the photon count rate was close to the instrument detection limit. The variation for different days was apparent in the two most concentrated samples, which indicated that wastewater samples must be analyzed for nanoscale particle measurement within the same day of collection. Upon addition of 10 mg l(-1) of nanosilica to wastewater effluent samples, the measured photon count rates were within 5% of the estimated values. The results indicated that photon count rate data can effectively complement various techniques currently available to detect nanoscale particles in wastewaters. PMID:22048710

Smeraldi, Josh; Ganesh, Rajagopalan; Safarik, Jana; Rosso, Diego

2012-01-01

121

Effective atomic numbers and mass attenuation coefficients of some thermoluminescent dosimetric compounds for total photon interaction  

Microsoft Academic Search

Effective atomic numbers for total gamma-ray interaction with some selected thermoluminescent dosimetric compounds such as barium acetate, barium sulfate, calcium carbonate, calcium sulfate, calcium sulfate dihydrate, cadmium sulfate (anhydrous), cadmium sulfate, strontium sulfate, and lithium fluoride have been calculated in the 1-keV to 20-MeV energy region. Experimental mass attenuation coefficients and effective atomic numbers for these compounds at selected photon

Shivaramu; R. Amutha; V. Ramprasath

1999-01-01

122

Quantum key distribution using vacuum-one-photon qubits: maximum number of transferable bits per particle  

E-print Network

Quantum key distribution schemes which employ encoding on vacuum-one-photon qubits are capable of transferring more information bits per particle than the standard schemes employing polarization or phase coding. We calculate the maximum number of classical bits per particle that can be securely transferred when the key distribution is performed with the BB84 and B92 protocols, respectively, using the vacuum-one-photon qubits. In particular, we show that for a generalized B92 protocol with the vacuum-one-photon qubits, a maximum of two bits per particle can be securely transferred. We also demonstrate the advantage brought about by performing a generalized measurement that is optimized for unambiguous discrimination of the encoded states: the parameter range where the transfer of two bits per particle can be achieved is dramatically enhanced as compared to the corresponding parameter range of projective measurements.

Su-Yong Lee; Se-Wan Ji; Hai-Woong Lee; Jae-Weon Lee; Janos A. Bergou

2009-07-20

123

Effective atomic numbers and mass attenuation coefficients of some thermoluminescent dosimetric compounds for total photon interaction  

SciTech Connect

Effective atomic numbers for total gamma-ray interaction with some selected thermoluminescent dosimetric compounds such as barium acetate, barium sulfate, calcium carbonate, calcium sulfate, calcium sulfate dihydrate, cadmium sulfate (anhydrous), cadmium sulfate, strontium sulfate, and lithium fluoride have been calculated in the 1-keV to 20-MeV energy region. Experimental mass attenuation coefficients and effective atomic numbers for these compounds at selected photon energies of 26.3, 33.2, 59.54, and 661.6 keV have been obtained from good geometry transmission measurements and compared with theoretical values. The effect of absorption edge on effective atomic numbers and its variation with energy, and nonvalidity of the Bragg`s mixture rule at incident photon energies closer to the absorption edges of constituent elements of compounds are discussed.

Shivaramu; Amutha, R.; Ramprasath, V. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Safety Research and Health Physics Group

1999-05-01

124

Photonic analog-to-digital converter based on the robust symmetrical number system  

NASA Astrophysics Data System (ADS)

A novel approach to realizing photonic analog-to-digital conversion with Gray-code-like property is proposed and demonstrated. Instead of using Mach-Zehnder modulators (MZMs) with different half-wave voltages, an array of MZMs with identical half-wave voltages are applied to realize quantization and encoding, which greatly simplifies the implementation. Multiple comparators with preset thresholds are applied at the output of each MZM to improve the number of bits. Through properly setting the bias voltages of the MZMs, a photonic analog to digital converter (ADC) based on the robust symmetrical number system (RSNS) coding method is realized. As an example, a 3-channel structure with maximum quantization level of 17 (corresponding to 4.09 bits) is investigated in detail. We show that the differential encoding technique can be applied in the proposed structure, which increases the equivalent number of bits of the ADC system.

Chen, Ying; Chi, Hao; Zheng, Shilie; Jin, Xiaofeng; Zhang, Xianmin

2012-11-01

125

Direct measurement of heralded single-photon statistics from a parametric down-conversion source  

SciTech Connect

We present a full triple-coincidence analysis of photon-pair states generated by spontaneous parametric down-conversion. By increasing the coherence time of the source with the help of an intracavity setup, our measurements are not spoiled by detection time jitter. Signal-idler, but also thermal signal-signal, correlations are clearly resolved in this regime. Via introduction of an artificial coincidence window, we discuss in detail the transition to the previously studied cases where typically no single-arm correlation is observed. We investigate the heralded antibunching characteristics to show that in our system further studies of continuously generated photon states, possibly higher-photon-number entangled states, can be performed with respect to their (non)applicability in quantum information tasks.

Hoeckel, David; Koch, Lars; Benson, Oliver [Nano Optics Group, Institute of Physics, Humboldt-Universitaet zu Berlin, Newtonstrasse 15, 12489 Berlin (Germany)

2011-01-15

126

Pulse pileup statistics for energy sensitive photon counting detectors with pulse height analysis  

NASA Astrophysics Data System (ADS)

Photon counting statistics with pulse pileup effects (PPE) have been investigated for detection schemes with two assumptions: a fixed deadtime (i.e., non-paralyable and paralyzable detection schemes) and a delta pulse shape. Analytical expressions have been developed which shed light on interesting findings: (1) the variance becomes smaller than mean with PPE; and (2) the variance-to-mean ratio (VMR) of narrow energy windows remains very close to 1. In this study, we experimentally investigate VMR with PPE with a variable deadtime (i.e., pulse height analysis) and bipolar and unipolar pulse shapes with a long tail in addition to the above cases. We will use Monte Carlo simulation for a systematic study and a physical photon counting detector to confirm the results.

Taguchi, Katsuyuki; Srivastava, Somesh; Tang, Qiulin; Caffo, Brian S.; Iwanczyk, Jan S.; Hartsough, Neal E.; Barber, William C.; Cammin, Jochen

2012-03-01

127

Analysis of Generation Mechanism of Photon-Number Squeezed Light Using Ultrashort Pulse and Asymmetric Fiber Loop Mirror  

Microsoft Academic Search

We analyze numerically the generation of photon-number squeezed light using an asymmetric fiber loop mirror. For photon-number squeezed light generation, the maximum squeezing can be obtained using this method. The evolution of the quantum noise for the optical pulse spectra is calculated using the quantized nonlinear Schrödinger equation and linearization approximation. It is shown that the squeezed light is generated

Junichi Higuchi; Norihiko Nishizawa; Masakazu Mori; Kazuo Yamane; Toshio Goto

2000-01-01

128

Measuring Quantum Correlations using Lossy Photon-Number-Resolving Detectors with Saturation  

E-print Network

The variance of difference of photocounts is an established measure of quantum correlations for quantum states of light. It enables us to discriminate between the classical correlation of a two-mode coherent state and the quantum correlation of a twin-beam state. We study the effect of loss and saturation of the photon-number-resolving detector on the measurement of the variance of difference of photocounts. An analytic function is derived for this variance, both for the coherent and the twin-beam states. It is found that the variance of difference of photocounts is no longer a reliable entanglement measure in the non-linear regime of the detector response but it remains useful in some range of values of average photon numbers of the incident light. We also quantify the linear regime of the detector with saturation which will be useful for calibration of the detector quantum efficiency.

Si-Hui Tan; Leonid A. Krivitsky; Berthold-Georg Englert

2012-10-30

129

Passive scheme with a photon-number-resolving detector for monitoring the untrusted source in a plug-and-play quantum-key-distribution system  

SciTech Connect

A passive scheme with a beam splitter and a photon-number-resolving (PNR) detector is proposed to verify the photon statistics of an untrusted source in a plug-and-play quantum-key-distribution system by applying a three-intensity decoy-state protocol. The practical issues due to statistical fluctuation and detection noise are analyzed. The simulation results show that the scheme can work efficiently when the total number of optical pulses sent from Alice to Bob is above 10{sup 8}, and the dark count rate of the PNR detector is below 0.5 counts/pulse, which is realizable with current techniques. Furthermore, we propose a practical realization of the PNR detector with a variable optical attenuator combined with a threshold detector.

Xu Bingjie; Peng Xiang; Guo Hong [CREAM Group, State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)

2010-10-15

130

Equatorial noise: Statistical study of its localization and the derived number density  

E-print Network

Equatorial noise: Statistical study of its localization and the derived number density F. Nemec a 2005 Abstract Results of a statistical study of equatorial noise emissions are presented of the equatorial noise. Secondly, we have found parameters of a Gaussian model of the frequency-averaged power

Santolik, Ondrej

131

Photon-number entangled states generated in Kerr media with optical parametric pumping  

SciTech Connect

Two nonlinear Kerr oscillators mutually coupled by parametric pumping are studied as a source of states entangled in photon numbers. Temporal evolution of entanglement quantified by negativity shows the effects of sudden death and birth of entanglement. Entanglement is preserved even in asymptotic states under certain conditions. The role of reservoirs at finite temperature in entanglement evolution is elucidated. Relation between generation of entangled states and violation of Cauchy-Schwartz inequality for oscillator intensities is found.

Kowalewska-Kudlaszyk, A.; Leonski, W.; Perina, Jan Jr. [Nonlinear Optics Division, Department of Physics, Adam Mickiewicz University, Umultowska 85, PL-61-614 Poznan (Poland)

2011-05-15

132

Characteristics of Noise and Photon Statistics of Fiber Components in Electro-Optical Systems  

NASA Astrophysics Data System (ADS)

This thesis presents a comprehensive study of the role of the fiber replicator in electro-optical systems. In the all fiber optical diagnostic system for the National Ignition Facility's DANTE data acquisition system running at 1550nm, the 8x fiber replicator was used to increase the SNR (Signal to Noise Ratio) of single-shot, electrical pulse measurements. In the system, Mach-Zehnder modulators were used to convert the electrical signals into optical signals. The fiber replicator was used to create identical copies of the optical signals. A High SNR was achieved through the averaging of these duplicated signals. Erbium-doped fiber amplifiers (EDFAs) were built to amplify the optical signals after the fiber replicator. The EDFAs applied in the DANTEEO system should have high gain, low noise, low background signals and high pulse-shape fidelity. In this thesis, we discussed the effect of different configurations and the type of Er-doped fibers on the gain and noise performance of EDFAs. We also used a simplified model for dynamic gain in EDFAs to explore the effect of the EDFA on the shape of the amplified pulse. Based on this model, the calculated pulse-shape distortions were found to be dependent on the EDFA configuration and the optical gain. We also investigated the photon statistics with the fiber replicator in a photon entanglement system. The entangled photons were created through the up-conversion and down-conversion of a Q-switch laser beam running at 1053nm. The different behavior between entangled photon and non-entangled single photons in the system with the fiber replicator are discussed.

Zhao, Cheng

133

Probabilistic and statistical relationships between number of vehicles and number of visitors at a geologic site in a National Park  

USGS Publications Warehouse

The National Park Service needs to establish in all of the national parks how large the parking lots should be in order to enjoy and presence our natural resources, for example, in the Delicate Arch in the Arches National Park. Probabilistic and statistical relationships were developed between the number of vehicles (N) at one time in the Wolfe Ranch parking lot and the number of visitors (X) at Delicate Arch 1.5 miles away in the Arches National Park, southeastern Utah. The value of N is determined such that 30 or more visitors are at the arch only 10% of the time.

Crovelli, R.A.

1997-01-01

134

Photon statistics and speckle visibility spectroscopy with partially coherent X-rays.  

PubMed

A new approach is proposed for measuring structural dynamics in materials from multi-speckle scattering patterns obtained with partially coherent X-rays. Coherent X-ray scattering is already widely used at high-brightness synchrotron lightsources to measure dynamics using X-ray photon correlation spectroscopy, but in many situations this experimental approach based on recording long series of images (i.e. movies) is either not adequate or not practical. Following the development of visible-light speckle visibility spectroscopy, the dynamic information is obtained instead by analyzing the photon statistics and calculating the speckle contrast in single scattering patterns. This quantity, also referred to as the speckle visibility, is determined by the properties of the partially coherent beam and other experimental parameters, as well as the internal motions in the sample (dynamics). As a case study, Brownian dynamics in a low-density colloidal suspension is measured and an excellent agreement is found between correlation functions measured by X-ray photon correlation spectroscopy and the decay in speckle visibility with integration time obtained from the analysis presented here. PMID:25343797

Li, Luxi; Kwa?niewski, Pawe?; Orsi, Davide; Wiegart, Lutz; Cristofolini, Luigi; Caronna, Chiara; Fluerasu, Andrei

2014-11-01

135

Counting fluorescent dye molecules on DNA origami by means of photon statistics.  

PubMed

Obtaining quantitative information about molecular assemblies with high spatial and temporal resolution is a challenging task in fluorescence microscopy. Single-molecule techniques build on the ability to count molecules one by one. Here, a method is presented that extends recent approaches to analyze the statistics of coincidently emitted photons to enable reliable counting of molecules in the range of 1-20. This method does not require photochemistry such as blinking or bleaching. DNA origami structures are labeled with up to 36 dye molecules as a new evaluation tool to characterize this counting by a photon statistics approach. Labeled DNA origami has a well-defined labeling stoichiometry and ensures equal brightness for all dyes incorporated. Bias and precision of the estimating algorithm are determined, along with the minimal acquisition time required for robust estimation. Complexes containing up to 18 molecules can be investigated non-invasively within 150 ms. The method might become a quantifying add-on for confocal microscopes and could be especially powerful in combination with STED/RESOLFT-type microscopy. PMID:23794455

Kurz, Anton; Schmied, Jürgen J; Grußmayer, Kristin S; Holzmeister, Phil; Tinnefeld, Philip; Herten, Dirk-Peter

2013-12-01

136

Quantum correlation between the junction-voltage fluctuation and the photon-number fluctuation in a semiconductor laser  

NASA Technical Reports Server (NTRS)

The photon-number fluctuation of the external field from a semiconductor laser - which was reduced to below the standard quantum limit - is shown to be correlated with the measured junction-voltage noise. The spectral density of the sum of the photon-number fluctuation and junction-voltage fluctuation falls below the squeezed photon-number fluctuation. This confirms the theoretical predictions that this correlation, which originates in the dipole interaction between the internal field and electron-hole pairs, extends into the quantum regime.

Richardson, W. H.; Yamamoto, Y.

1991-01-01

137

Branching and path-deviation of positive streamers resulting from statistical photon transport  

NASA Astrophysics Data System (ADS)

The branching and change in direction of propagation (path-deviation) of positive streamers in molecular gases such as air likely require a statistical process which perturbs the head of the streamer and produces an asymmetry in its space charge density. In this paper, the mechanisms for path-deviation and branching of atmospheric pressure positive streamer discharges in dry air are numerically investigated from the viewpoint of statistical photon transport and photoionization. A statistical photon transport model, based on randomly selected emitting angles and mean-free-path for absorption, was developed and embedded into a fluid-based plasma transport model. The hybrid model was applied to simulations of positive streamer coaxial discharges in dry air at atmospheric pressure. The results show that secondary streamers, often spatially isolated, are triggered by the random photoionization and interact with the thin space charge layer (SCL) of the primary streamer. This interaction may be partly responsible for path-deviation and streamer branching. The general process consists of random remote photo-electron production which initiates a back-traveling electron avalanche, collision of this secondary avalanche with the primary streamer and the subsequent perturbation to its SCL. When the SCL is deformed from a symmetric to an asymmetric shape, the streamer can experience an abrupt change in the direction of propagation. If the SCL is sufficiently perturbed and essentially broken, local maxima in the SCL can develop into new streamers, leading to streamer branching. During the propagation of positive streamers, this mechanism can take place repetitively in time and space, thus producing multi-level branching and more than two branches within one level.

Xiong, Zhongmin; Kushner, Mark J.

2014-12-01

138

Performance of Number-Between g Type Statistical Control Charts for Monitoring Adverse Events  

Microsoft Academic Search

Alternate Shewhart-type statistical control charts, called “g” and “h” charts, have been developed for monitoring the number of cases between hospital-acquired infections and other adverse events, such as heart surgery complications, catheter-related infections, surgical site infections, contaminated needle sticks, medication errors and other care induced concerns. This article investigates the statistical properties of these new charts and illustrates several design

James C. Benneyan

2001-01-01

139

Performance of Number-Between g-type Statistical Control Charts for Monitoring Adverse Events  

Microsoft Academic Search

Abstract Alternate Shewhart-type statistical control charts, called “g” and “ h” charts, have been de- veloped for monitoring the number,of cases between hospital-acquired infections and other adverse events, such as heart surgery complications, catheter-relatedinfections, surgical site infections, contaminated needle sticks, medication errors, and other care-induced concerns. This article investigates the statistical properties of these new charts and illustrates several design

James C. Benneyan

2001-01-01

140

Practical and fast quantum random number generation based on photon arrival time relative to external reference  

NASA Astrophysics Data System (ADS)

We present a practical high-speed quantum random number generator, where the timing of single-photon detection relative to an external time reference is measured as the raw data. The bias of the raw data can be substantially reduced compared with the previous realizations. The raw random bit rate of our generator can reach 109 Mbps. We develop a model for the generator and evaluate the min-entropy of the raw data. Toeplitz matrix hashing is applied for randomness extraction, after which the final random bits are able to pass the standard randomness tests.

Nie, You-Qi; Zhang, Hong-Fei; Zhang, Zhen; Wang, Jian; Ma, Xiongfeng; Zhang, Jun; Pan, Jian-Wei

2014-02-01

141

Reversing the weak measurement of an arbitrary field with finite photon number  

E-print Network

Reversing the weak measurement of an arbitrary field with finite photon number Qingqing Sun,1,* M. Al-Amri,2 and M. Suhail Zubairy1 1Department of Physics and Institute of Quantum Studies, Texas A&M University, College Station, Texas 77843, USA 2...; Level structure in step #1;II#2;. The classical field is #16;? polarized. #1;c#2; The profiles of the fields required for the adiabatic passages. #1;d#2; The system diagram. SUN, AL-AMRI, AND ZUBAIRY PHYSICAL REVIEW A 80, 033838 #1;2009#2; 033838...

Sun, Qingqing; Al-Amri, M.; Zubairy, M. Suhail.

2009-01-01

142

Statistical Power to Detect the Correct Number of Classes in Latent Profile Analysis  

PubMed Central

Little research has examined factors influencing statistical power to detect the correct number of latent classes using latent profile analysis (LPA). This simulation study examined power related to inter-class distance between latent classes given true number of classes, sample size, and number of indicators. Seven model selection methods were evaluated. None had adequate power to select the correct number of classes with a small (Cohen’s d = .2) or medium (d = .5) degree of separation. With a very large degree of separation (d = 1.5), the Lo-Mendell-Rubin test (LMR), adjusted LMR, bootstrap likelihood-ratio test, BIC, and sample-size adjusted BIC were good at selecting the correct number of classes. However, with a large degree of separation (d = .8), power depended on number of indicators and sample size. The AIC and entropy poorly selected the correct number of classes, regardless of degree of separation, number of indicators, or sample size. PMID:24489457

Coxe, Stefany; Cham, Heining

2012-01-01

143

Statistical Modelling of the Relationship Between Main Development Region Sea Surface Temperature and Atlantic Basin Hurricane Numbers  

E-print Network

We are building a hurricane number prediction scheme that relies, in part, on statistical modelling of the empirical relationship between Atlantic sea surface temperatures and Atlantic basin hurricane numbers. We test out a number of simple statistical models for this relationship, using data from 1900 to 2005 and data from 1950 to 2005, and for both all hurricane numbers and intense hurricane numbers.

Binter, R; Khare, S; Binter, Roman; Jewson, Stephen; Khare, Shree

2007-01-01

144

Nonequilibrium quantum fluctuations of a dispersive medium: Spontaneous emission, photon statistics, entropy generation, and stochastic motion  

NASA Astrophysics Data System (ADS)

We study the implications of quantum fluctuations of a dispersive medium, under steady rotation, either in or out of thermal equilibrium with its environment. A rotating object exhibits a quantum instability by dissipating its mechanical motion via spontaneous emission of photons, as well as internal heat generation. Universal relations are derived for the radiated energy and angular momentum as trace formulas involving the object's scattering matrix. We also compute the quantum noise by deriving the full statistics of the radiated photons out of thermal and/or dynamic equilibrium. The (entanglement) entropy generation is quantified and the total entropy is shown to be always increasing. Furthermore, we derive a Fokker-Planck equation governing the stochastic angular motion resulting from the fluctuating backreaction frictional torque. As a result, we find a quantum limit on the uncertainty of the object's angular velocity in steady rotation. Finally, we show in some detail that a rotating object drags nearby objects, making them spin parallel to its axis of rotation. A scalar toy model is introduced to simplify the technicalities and ease the conceptual complexities and then a detailed discussion of quantum electrodynamics is presented.

Maghrebi, Mohammad F.; Jaffe, Robert L.; Kardar, Mehran

2014-07-01

145

Nonequilibrium quantum fluctuations of a dispersive medium: Spontaneous emission, photon statistics, entropy generation, and stochastic motion  

E-print Network

We study the implications of quantum fluctuations of a dispersive medium, under steady rotation, either in or out of thermal equilibrium with its environment. A rotating object exhibits a quantum instability by dissipating its mechanical motion via spontaneous emission of photons, as well as internal heat generation. Universal relations are derived for the radiated energy and angular momentum as trace formulas involving the object's scattering matrix. We also compute the quantum noise by deriving the full statistics of the radiated photons out of thermal and/or dynamic equilibrium. The (entanglement) entropy generation is quantified, and the total entropy is shown to be always increasing. Furthermore, we derive a Fokker-Planck equation governing the stochastic angular motion resulting from the fluctuating back-reaction frictional torque. As a result, we find a quantum limit on the uncertainty of the object's angular velocity in steady rotation. Finally, we show in some detail that a rotating object drags nearby objects, making them spin parallel to its axis of rotation. A scalar toy model is introduced in the first part to simplify the technicalities and ease the conceptual complexities; a detailed discussion of quantum electrodynamics is presented in the second part.

Mohammad F. Maghrebi; Robert L. Jaffe; Mehran Kardar

2014-01-03

146

Photonic forces in the near field of statistically homogeneous fluctuating sources  

E-print Network

Electromagnetic sources, as e.g. lasers, antennas, diffusers or thermal sources, produce a wavefield that interacts with objects to transfer them its momentum. We show that the photonic force exerted on a small particle in the near field of a planar statistically homogeneous fluctuating source uniquely depends and acts along the coordinate perpendicular to its surface. The gradient part of this force is contributed by only the evanescent components of the emitted field, its sign being opposite to that of the real part of the particle polarizability. The non-conservative force part is uniquely due to the propagating components, being repulsive and constant. Also, the source coherence length adds a degree of freedom since it largely affects these forces. The excitation of plasmons in the source surface drastically enhances the gradient force. Hence, partially coherent wavefields from fluctuating sources constitute new concepts for particle manipulation at the subwavelength scale

Aunon, Juan Miguel

2012-01-01

147

Nonclassicality and the concept of local constraints on the photon number distribution  

E-print Network

We exploit results from the classical Stieltjes moment problem to bring out the totality of all the information regarding phase insensitive nonclassicality of a state as captured by the photon number distribution p_n. Central to our approach is the realization that n !p_n constitutes the sequence of moments of a (quasi) probability distribution, notwithstanding the fact that p_n can by itself be regarded as a probability distribution. This leads to classicality restrictions on p_n that are local in n involving p_n's for only a small number of consecutive n's, enabling a critical examination of the conjecture that oscillation in p_n is a signature of nonclassicality.

Simon, R; Mukunda, N; Selvadoray, Mary

1997-01-01

148

Nonclassicality and the concept of local constraints on the photon number distribution  

E-print Network

We exploit results from the classical Stieltjes moment problem to bring out the totality of all the information regarding phase insensitive nonclassicality of a state as captured by the photon number distribution p_n. Central to our approach is the realization that n !p_n constitutes the sequence of moments of a (quasi) probability distribution, notwithstanding the fact that p_n can by itself be regarded as a probability distribution. This leads to classicality restrictions on p_n that are local in n involving p_n's for only a small number of consecutive n's, enabling a critical examination of the conjecture that oscillation in p_n is a signature of nonclassicality.

R. Simon; Mary Selvadoray; Arvind; N. Mukunda

1997-08-23

149

The Statistics of the Number of Neutron Collisions Prior to Absorption  

E-print Network

the need for enhanced information extraction from neutron detection methods for nuclear material management or lithium. The neutron detection occurs in two steps: First, the neutron gener- ates a scintillation pulseThe Statistics of the Number of Neutron Collisions Prior to Absorption Sara A. Pozzi* Oak Ridge

Pázsit, Imre

150

Building a confidence interval for the number of signals in noise using likelihood ratio test statistics  

Microsoft Academic Search

We propose a multi-step procedure for constructing a confidence interval for the number of signals present in noise. The proposed procedure uses likelihood ratio statistics and their simulated percentiles in a sequential manner to estimate the upper and lower limits for the confidence interval. A preference zone in the parameter space of the population eigenvalues is defined and used to

Joshua S. Markow; Michael C. Wicks; P. Chen

2006-01-01

151

A unified statistical framework for material decomposition using multienergy photon counting x-ray detectors  

SciTech Connect

Purpose: Material decomposition using multienergy photon counting x-ray detectors (PCXD) has been an active research area over the past few years. Even with some success, the problem of optimal energy selection and three material decomposition including malignant tissue is still on going research topic, and more systematic studies are required. This paper aims to address this in a unified statistical framework in a mammographic environment.Methods: A unified statistical framework for energy level optimization and decomposition of three materials is proposed. In particular, an energy level optimization algorithm is derived using the theory of the minimum variance unbiased estimator, and an iterative algorithm is proposed for material composition as well as system parameter estimation under the unified statistical estimation framework. To verify the performance of the proposed algorithm, the authors performed simulation studies as well as real experiments using physical breast phantom and ex vivo breast specimen. Quantitative comparisons using various performance measures were conducted, and qualitative performance evaluations for ex vivo breast specimen were also performed by comparing the ground-truth malignant tissue areas identified by radiologists.Results: Both simulation and real experiments confirmed that the optimized energy bins by the proposed method allow better material decomposition quality. Moreover, for the specimen thickness estimation errors up to 2 mm, the proposed method provides good reconstruction results in both simulation and real ex vivo breast phantom experiments compared to existing methods.Conclusions: The proposed statistical framework of PCXD has been successfully applied for the energy optimization and decomposition of three material in a mammographic environment. Experimental results using the physical breast phantom and ex vivo specimen support the practicality of the proposed algorithm.

Choi, Jiyoung; Kang, Dong-Goo; Kang, Sunghoon; Sung, Younghun [Samsung Advanced Institute of Technology (SAIT), San 14, Nong-seo dong, Giheung-gu, Yongin, Kyunggi 446-712 (Korea, Republic of)] [Samsung Advanced Institute of Technology (SAIT), San 14, Nong-seo dong, Giheung-gu, Yongin, Kyunggi 446-712 (Korea, Republic of); Ye, Jong Chul [Bio-Imaging and Signal Processing Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejon 305-701 (Korea, Republic of)] [Bio-Imaging and Signal Processing Laboratory, Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejon 305-701 (Korea, Republic of)

2013-09-15

152

Measuring photon-photon interactions via photon detection  

E-print Network

The strong non-linearity plays a significant role in physics, particularly, in designing novel quantum sources of light and matter as well as in quantum chemistry or quantum biology. In simple systems, the photon-photon interaction can be determined analytically. However, it becomes challenging to obtain it for more compex systems. Therefore, we show here how to measure strong non-linearities via allowing the sample to interact with a weakly pumped quantized leaking optical mode. We found that the detected mean-photon number versus pump-field frequency shows several peaks. Interestingly, the interval between neighbour peaks equals the photon-photon interaction potential. Furthermore, the system exhibits sub-Poissonian photon statistics, entanglement and photon switching with less than one photon. Finally, we connect our study with existing related experiments.

Mihai A. Macovei

2010-06-18

153

Measuring photon-photon interactions via photon detection  

SciTech Connect

Strong nonlinearity plays a significant role in physics, particularly in the design of novel quantum sources of light and matter as well as in quantum chemistry and quantum biology. In simple systems, the photon-photon interaction can be determined analytically. However, it becomes challenging to obtain it for more complex systems. Therefore, we show here how to measure strong nonlinearities by allowing the sample to interact with a weakly pumped quantized leaking optical mode. We found that the detected mean photon number versus pump-field frequency shows several peaks. Interestingly, the interval between neighboring peaks equals the photon-photon interaction potential. Furthermore, the system exhibits sub-Poissonian photon statistics, entanglement, and photon switching with less than one photon. Finally, we connect our study with existing experiments.

Macovei, Mihai A. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

2010-12-15

154

Statistical properties of online avatar numbers in a massive multiplayer online role-playing game  

NASA Astrophysics Data System (ADS)

Massive multiplayer online role-playing games (MMORPGs) have been very popular in the past few years. The profit of an MMORPG company is proportional to how many users registered, and the instant number of online avatars is a key factor to assess how popular an MMORPG is. We use the online-offline logs on an MMORPG server to reconstruct the instant number of online avatars per second and investigate its statistical properties. We find that the online avatar number exhibits one-day periodic behavior and clear intraday pattern, the fluctuation distribution of the online avatar numbers has a leptokurtic non-Gaussian shape with power-law tails, and the increments of online avatar numbers after removing the intraday pattern are uncorrelated and the associated absolute values have long-term correlation. In addition, both time series exhibit multifractal nature.

Jiang, Zhi-Qiang; Ren, Fei; Gu, Gao-Feng; Tan, Qun-Zhao; Zhou, Wei-Xing

2010-02-01

155

Statistical properties of online avatar numbers in a massive multiplayer online role-playing game  

E-print Network

Massive multiplayer online role-playing games (MMORPGs) are very popular in past few years. The profit of an MMORPG company is proportional to how many users registered, and the instant number of online avatars is a key factor to assess how popular an MMORPG is. We use the on-off-line logs on an MMORPG server to reconstruct the instant number of online avatars per second and investigate its statistical properties. We find that the online avatar number exhibits one-day periodic behavior and clear intraday pattern, the fluctuation distribution of the online avatar numbers has a leptokurtic non-Gaussian shape with power-law tails, and the increments of online avatar numbers after removing the intraday pattern are uncorrelated and the associated absolute values have long-term correlation. In addition, both time series exhibit multifractal nature.

Jiang, Zhi-Qiang; Gu, Gao-Feng; Tan, Qun-Zhao; Zhou, Wei-Xing

2009-01-01

156

Statistical Modelling of the Relationship Between Main Development Region Sea Surface Temperature and \\emph{Landfalling} Atlantic Basin Hurricane Numbers  

E-print Network

We are building a hurricane number prediction scheme that relies, in part, on statistical modelling of the empirical relationship between Atlantic sea surface temperatures and landfalling hurricane numbers. We test out a number of simple statistical models for that relationship, using data from 1900 to 2005 and data from 1950 to 2005, and for both all hurricane numbers and intense hurricane numbers. The results are very different from the corresponding analysis for basin hurricane numbers.

Binter, R; Khare, S; Binter, Roman; Jewson, Stephen; Khare, Shree

2007-01-01

157

Hurst’s rescaled range statistical analysis for pseudorandom number generators used in physical simulations  

Microsoft Academic Search

The rescaled range statistical analysis (R\\/S) is proposed as a new method to\\u000adetect correlations in pseudorandom number generators used in Monte Carlo\\u000asimulations. In an extensive test it is demonstrated that the RS analysis\\u000aprovides a very sensitive method to reveal hidden long run and short run\\u000acorrelations. Several widely used and also some recently proposed pseudorandom\\u000anumber generators

B. M. Gammel

1998-01-01

158

Quantum fingerprinting with coherent states and a constant mean number of photons  

NASA Astrophysics Data System (ADS)

We present a protocol for quantum fingerprinting that is ready to be implemented with current technology and is robust to experimental errors. The basis of our scheme is an implementation of the signal states in terms of a coherent state in a superposition of time-bin modes. Experimentally, this requires only the ability to prepare coherent states of low amplitude and to interfere them in a balanced beam splitter. The states used in the protocol are arbitrarily close in trace distance to states of O (log2n) qubits, thus exhibiting an exponential separation in abstract communication complexity compared to the classical case. The protocol uses a number of optical modes that is proportional to the size n of the input bit strings but a total mean photon number that is constant and independent of n. Given the expended resources, our protocol achieves a task that is provably impossible using classical communication only. In fact, even in the presence of realistic experimental errors and loss, we show that there exist a large range of input sizes for which our quantum protocol transmits an amount of information that can be more than two orders of magnitude smaller than a classical fingerprinting protocol.

Arrazola, Juan Miguel; Lütkenhaus, Norbert

2014-06-01

159

TEGS-CN: A Statistical Method for Pathway Analysis of Genome-wide Copy Number Profile  

PubMed Central

The effects of copy number alterations make up a significant part of the tumor genome profile, but pathway analyses of these alterations are still not well established. We proposed a novel method to analyze multiple copy numbers of genes within a pathway, termed Test for the Effect of a Gene Set with Copy Number data (TEGS-CN). TEGS-CN was adapted from TEGS, a method that we previously developed for gene expression data using a variance component score test. With additional development, we extend the method to analyze DNA copy number data, accounting for different sizes and thus various numbers of copy number probes in genes. The test statistic follows a mixture of X2 distributions that can be obtained using permutation with scaled X2 approximation. We conducted simulation studies to evaluate the size and the power of TEGS-CN and to compare its performance with TEGS. We analyzed a genome-wide copy number data from 264 patients of non-small-cell lung cancer. With the Molecular Signatures Database (MSigDB) pathway database, the genome-wide copy number data can be classified into 1814 biological pathways or gene sets. We investigated associations of the copy number profile of the 1814 gene sets with pack-years of cigarette smoking. Our analysis revealed five pathways with significant P values after Bonferroni adjustment (<2.8 × 10?5), including the PTEN pathway (7.8 × 10?7), the gene set up-regulated under heat shock (3.6 × 10?6), the gene sets involved in the immune profile for rejection of kidney transplantation (9.2 × 10?6) and for transcriptional control of leukocytes (2.2 × 10?5), and the ganglioside biosynthesis pathway (2.7 × 10?5). In conclusion, we present a new method for pathway analyses of copy number data, and causal mechanisms of the five pathways require further study.

Huang, Yen-Tsung; Hsu, Thomas; Christiani, David C

2014-01-01

160

Parity assignments in 172,174Yb using polarized photons and the K quantum number in rare earth nuclei  

E-print Network

The 100 % polarized photon beam at the High Intensity gamma-ray Source (HIgS) at Duke University has been used to determine the parity of six dipole excitations between 2.9 and 3.6 MeV in the deformed nuclei 172,174 Yb in photon scattering (g,g') experiments. The measured parities are compared with previous assignments based on the K quantum number that had been assigned in Nuclear Resonance Fluorescence (NRF) experiments by using the Alaga rules. A systematic survey of the relation between gamma-decay branching ratios and parity quantum numbers is given for the rare earth nuclei.

D. Savran; S. Müller; A. Zilges; M. Babilon; M. W. Ahmed; J. H. Kelley; A. Tonchev; W. Tornow; H. R. Weller; N. Pietralla; J. Li; I. V. Pinayev; Y. K. Wu

2005-01-11

161

Photon-number squeezing with a noisy femtosecond fiber laser amplifier source using a collinear balanced detection technique.  

PubMed

We experimentally demonstrate photon-number squeezing at 1.55 ?m using a noisy erbium-doped fiber amplifier (EDFA). We employ a collinear balanced detection (CBD) technique, where the intensity noise at a specific radio frequency is canceled between two pulse trains. In spite of substantially large excess noise (>10 dB) in an EDFA due to amplified spontaneous emission, we successfully cancel the intensity noise and achieve a shot noise limit at a specific radio frequency with the CBD technique. We exploit two sets of fiber polarization interferometers to generate squeezed light and observe a maximal photon-number squeezing of -2.6 dB. PMID:24150352

Sawai, Shota; Kawauchi, Hikaru; Hirosawa, Kenichi; Kannari, Fumihiko

2013-10-21

162

Vermglio has brought up a number of interesting points. 1) Statistical models. It would be helpful if the authors could agree that either statistical model  

E-print Network

Verméglio has brought up a number of interesting points. 1) Statistical models. It would be helpful if the authors could agree that either statistical model (supercomplexes or random distribution) can in principle time scale in chromatophores. Both these results show that, at least under these conditions, most

Crofts, Antony R.

163

Statistics of the cosmic Mach number from numerical simulations of a cold dark matter universe  

NASA Technical Reports Server (NTRS)

Results are presented of an analysis of the cosmic Mach number, M, the ratio of the streaming velocity, v, to the random velocity dispersion, sigma, of galaxies in a given patch of the universe, which was performed on the basis of hydrodynamical simulations of the cold dark matter scenario. Galaxy formation is modeled by application of detailed physical processes rather than by the ad hoc assumption of 'bias' between dark matter and galaxy fluctuations. The correlation between M and sigma is found to be very weak for both components. No evidence is found for a physical 'velocity bias' in the quantities which appear in the definition of M. Standard cold-dark-matter-dominated universes are in conflict, at a statistically significant level, with the available observation, in that they predict a Mach number considerably lower than is observed.

Suto, Yasushi; Cen, Renyue; Ostriker, Jeremiah P.

1992-01-01

164

Quantum-key-distribution protocols without sifting that are resistant to photon-number-splitting attacks  

NASA Astrophysics Data System (ADS)

We propose a family of sifting-less quantum-key-distribution protocols which use reverse reconciliation, and are based on weak coherent pulses (WCPs) polarized along m different directions. When m=4, the physical part of the protocol is identical to most experimental implementations of BB84 [Bennett and Brassard, in Proceedings of the IEEE International Conference on Computers, Systems, and Signal Processing (IEEE, New York, 1984)] and SARG04 [Scarani, Acín, Ribordy, and Gisin, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.92.057901 92, 057901 (2004); Acín, Gisin, and Scarani, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.69.012309 69, 012309 (2004)] protocols and they differ only in classical communications and data processing. We compute their total key rate as a function of the channel transmission T, using general information theoretical arguments, and we show that they have a higher key rate than the more standard protocols, both for fixed and optimized average photon number of the WCPs. When no decoy-state protocols (DSPs) [Hwang, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.91.057901 91, 057901 (2003); Lo, Ma, and Chen, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.94.230504 94, 230504 (2005); Wang, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.72.012322 72, 012322 (2005)] are applied, the scaling of the key rate with transmission is improved from T2 for BB84 to T1+(1)/(m-2). If a DSP is applied, we show how the key rates scale linearly with T, with an improvement of the prefactor by 75.96% for m=4. High values of m allow one to asymptotically approach the key rate obtained with ideal single-photon pulses. The fact that the key rates of these sifting-less protocols are higher compared to those of the aforementioned more standard protocols show that the latter are not optimal, since they do not extract all the available secret keys from the experimental correlations.

Grazioso, Fabio; Grosshans, Frédéric

2013-11-01

165

Progress with a High Atwood Number Statistically Steady Rayleigh-Taylor Mix Experiment  

NASA Astrophysics Data System (ADS)

A novel gas channel experiment is used to study the non-equilibrium development of high Atwood number Rayleigh-Taylor mixing. Two gas streams, one containing air and the other containing Helium - air mixture flow parallel to each other separated by a thin splitter plate. The streams meet at the end of the splitter plate leading to the formation of an unstable interface and initiation of buoyancy driven mixing. This buoyancy driven mixing experiment allows for long data collection times, short transients and is statistically steady. The facility is capable of large Atwood number studies (upto 0.75). Here, we describe recent work to measure the self similar evolution of mixing at large density differences (At ˜ 0.25). Diagnostics include a constant temperature Hot Wire anemometer and high resolution thermocouple measurements. The Hot wire probe gives velocity statistics of the mixing layer. Spectra of velocity and temperature are presented. Analysis of the measured data is used to explain the structure of mixing as it develops to a self-similar regime in this flow.

Banerjee, Arindam; Andrews, Malcolm J.

2004-11-01

166

Belief In Numbers: When and why women disbelieve tailored breast cancer risk statistics  

PubMed Central

Objective To examine when and why women disbelieve tailored information about their risk of developing breast cancer. Methods 690 women participated in an online program to learn about medications that can reduce the risk of breast cancer. The program presented tailored information about each woman’s personal breast cancer risk. Half of women were told how their risk numbers were calculated, whereas the rest were not. Later, they were asked whether they believed that the program was personalized, and whether they believed their risk numbers. If a woman did not believe her risk numbers, she was asked to explain why. Results Beliefs that the program was personalized were enhanced by explaining the risk calculation methods in more detail. Nonetheless, nearly 20% of women did not believe their personalized risk numbers. The most common reason for rejecting the risk estimate was a belief that it did not fully account for personal and family history. Conclusions The benefits of tailored risk statistics may be attenuated by a tendency for people to be skeptical that these risk estimates apply to them personally. Practice Implications Decision aids may provide risk information that is not accepted by patients, but addressing the patients’ personal circumstances may lead to greater acceptance. PMID:23623330

Scherer, Laura D.; Ubel, Peter A.; McClure, Jennifer; Green, Sarah M.; Alford, Sharon Hensley; Holtzman, Lisa; Exe, Nicole; Fagerlin, Angela

2013-01-01

167

Mixed velocity passive scalar statistics in high-Reynolds-number turbulence  

NASA Astrophysics Data System (ADS)

Statistics of the mixed velocity passive scalar field and its Reynolds number dependence are studied in quasi-isotropic decaying grid turbulence with an imposed mean temperature gradient. The turbulent Reynolds number (using the Taylor microscale as the length scale), R[lambda], is varied over the range 85 [less-than-or-eq, slant] R[lambda] [less-than-or-eq, slant] 582. The passive scalar under consideration is temperature in air. The turbulence is generated by means of an active grid and the temperature fluctuations result from the action of the turbulence on the mean temperature gradient. The latter is created by differentially heating elements at the entrance to the wind tunnel plenum chamber. The mixed velocity passive scalar field evolves slowly with Reynolds number. Inertial-range scaling exponents of the co-spectra of transverse velocity and temperature, Ev[theta](k1), and its real-space analogue, the ‘heat flux structure function,’ [left angle bracket][Delta]v(r)[Delta][theta](r)[right angle bracket], show a slow evolution towards their theoretical predictions of [minus sign]7/3 and 4/3, respectively. The sixth-order longitudinal mixed structure functions, [left angle bracket]([Delta]u(r))2([Delta][theta](r))4[right angle bracket], exhibit inertial-range structure function exponents of 1.36 1.52. However, discrepancies still exist with respect to the various methods used to estimate the scaling exponents, the value of the scalar intermittency exponent, [mu][theta], and the effects of large-scale phenomena (namely shear, decay and turbulent production of [left angle bracket][theta]2[right angle bracket]) on [left angle bracket]([Delta]u(r))2([Delta][theta](r))4[right angle bracket]. All the measured fine-scale statistics required to be zero in a locally isotropic flow are, or tend towards, zero in the limit of large Reynolds numbers. The probability density functions (PDFs) of [Delta]v(r)[Delta][theta](r) exhibit roughly exponential tails for large separations and super-exponential tails for small separations, thus displaying the effects of internal intermittency. As the Reynolds number increases, the PDFs become symmetric at the smallest scales in accordance with local isotropy. The expectation of the transverse velocity fluctuation conditioned on the scalar fluctuation is linear for all Reynolds numbers, with slope equal to the correlation coefficient between v and [theta]. The expectation of (a surrogate of) the Laplacian of the scalar reveals a Reynolds number dependence when conditioned on the transverse velocity fluctuation (but displays no such dependence when conditioned on the scalar fluctuation). This former Reynolds number dependence is consistent with Taylor’s diffusivity independence hypothesis. Lastly, for the statistics measured, no violations of local isotropy were observed.

Mydlarski, L.

2003-01-01

168

A model independent lower limit on the number of Gamma Ray Burst hosts from repeater statistics  

E-print Network

We present a general statistical analysis of Gamma Ray Bursts embedded in a host population. If no host generates more than one observed burst, then we show that there is a model independent lower bound on the number of hosts, $H$, of the form $H > c B^2$, where B is the number of observed bursts, and $c$ is a constant of order one which depends on the confidence level (CL) attached to the bound. An analysis by Tegmark et al. (1996) shows that the BATSE 3B catalog of 1122 bursts is consistent with no repeaters being present, and assuming that this is indeed the case, our result implies a host population with at least H=1.2x10^6 members. Without the explicit assumption of no repeaters, a Bayesian analysis based on the results of Tegmark et al. (1996) can be performed which gives the weaker bound of $H>1.7\\times 10^5$ at the 90% CL. In the light of the non-detection of identifiable hosts in the small error-boxes associated with transient counterparts to GRBs, this result gives a model independent lower bound to the number of any rare or exotic hosts. If in fact GRBs are found to be associated with a particular sub-class of galaxies, then an analysis along the lines presented here can be used to place a lower bound on the fraction of galaxies in this sub-class. Another possibility is to treat galaxy clusters (rather than individual galaxies) as the host population, provided that the angular size of each cluster considered is less than the resolution of the detector. Finally, if repeaters are ever detected in a statistically significant manner, this analysis can be readily adapted to find upper and lower limits on $H$.

Anupam Singh; Mark Srednicki

1997-05-23

169

Photonics  

NASA Astrophysics Data System (ADS)

After developing various kinds of photodetectors such as phototubes, photomultiplier tubes, image pick up tubes, solid state photodetectors and a variety of light sources, we also started to develop integrated systems utilizing new detectors or imaging devices. These led us to the technology for a single photon counting imaging and detection of picosecond and femtosecond phenomena. Through those experiences, we gained the understanding that photon is a paste of substances, and yet we know so little about photon. By developing various technology for many fields such as analytical chemistry, high energy physics, medicine, biology, brain science, astronomy, etc., we are beginning to understand that the mind and life are based on the same matter, that is substance. Since humankind has so little knowledge about the substance concerning the mind and life, this makes some confusion on these subjects at this moment. If we explore photonics more deeply, many problems we now have in the world could be solved. By creating new knowledge and technology, I believe we will be able to solve the problems of illness, aging, energy, environment, human capability, and finally, the essential healthiness of the six billion human beings in the world.

Hiruma, Teruo

1993-04-01

170

Photons  

NSDL National Science Digital Library

In this activity using an open space and a thick rope, students simulate the movement of photons from the Sun. The resource is part of the teacher's guide accompanying the video, NASA Why Files: The Case of the Mysterious Red Light. Lesson objectives supported by the video, additional resources, teaching tips and an answer sheet are included in the teacher's guide.

171

Distribution analysis of the photon correlation spectroscopy of discrete numbers of dye molecules conjugated to DNA  

Microsoft Academic Search

The formation of protein complexes with other proteins and nucleic acids is critical to biological function. Although it is relatively easy to identify the components present in these complexes, it is often difficult to determine their exact stoichiometry and obtain information about the homogeneity of the sample from bulk measurements. We demonstrate the use of single molecule photon-pair correlation spectroscopy

Samantha Fore; Ted A. Laurence; Yin Yeh; Rod Balhorn; Christopher W. Hollars; Monique Cosman; Thomas Huser

2005-01-01

172

Volume175.number3 CHEMICALPHYSICSLETTERS 7December1990 Thermal history and temperature-dependent photon echo  

E-print Network

-dependent photon echo and hole burning linewidths in low temperature glycerol glasses K.A. Littau `, A. Elschner resorufin in glycerol glass from 1 to 25 K. At low temperature a factor of ~4 difference between the glass transition temperature [2,3 1. This lack of total randomness has been demon- strated

Fayer, Michael D.

173

774 OPTICS LETTERS / Vol. 24, No. 11 / June 1, 1999 Photon-number squeezing in the normal-dispersion regime  

E-print Network

experimentally and theoretically. © 1999 Optical Society of America OCIS codes: 270.6570, 270.5530, 270 in the normal-dispersion regime by use of a highly asym- metric Sagnac loop geometry and measure a maxi- mum of 1.7 6 0.1 dB (33%) of photon-number squeezing below shot-noise level. Correcting for linear system

Bergman, Keren

174

The effect of beam energy and number of fields on photon-based IMRT for deep-seated targets  

Microsoft Academic Search

Purpose: To examine the influence of energy and number of beams on nontarget dose when using intensity-modulated radiation therapy (IMRT) to treat deep-seated targets.Methods and Materials: Ten patients with prostate cancer (36–226 cc) treated locally to 75.6 Gy were studied. IMRT plans were created for 6-, 10-, and 18-MV photons using 4, 6, 9, and 11 coplanar nonopposed fields. Plans,

Andrea Pirzkall; Mark P Carol; Barby Pickett; Ping Xia; Mack Roach; Lynn J Verhey

2002-01-01

175

Obtaining photon transit time distribution of diffuse media using laser speckle statistics for imaging applicatlons  

Microsoft Academic Search

Optical diffusion tomography typically uses a low coherence source, such as an LED, whose output intensity is sinusoidally modulated, and involves a coherent detection scheme at this modulation frequency. These measurements yield the frequency domain representation of the photon transit time distribution for travel through a scattering medium. Inversion of this data, based upon a diffusion equation model for the

M. A. Webster; J. D. McKinney; A. M. Weiner; K. J. Webb

2000-01-01

176

Statistical analyses of the magnet data for the Advanced Photon Source storage ring magnets  

Microsoft Academic Search

The statistics of the measured magnetic data of 80 dipole, 400 quadrupole, and 280 sextupole magnets of conventional resistive designs for the APS storage ring is summarized. In order to accommodate the vacuum chamber, the curved dipole has a C-type cross section and the quadrupole and sextupole cross sections have 180? and 120? symmetries, respectively. The data statistics include the

S. H. Kim; D. W. Carnegie; C. Doose; R. Hogrefe; K. Kim; R. Merl

1996-01-01

177

Study of the effects of photon statistics on Thomson scattering data  

SciTech Connect

A computer code has been developed which simulates the counting statistics of a Thomson scattering measurement. The scattered and background signals in each of the wavelength channels are assumed to obey Poisson statistics, and the spectral data are fitted to a Gaussian curve using a nonlinear least-squares fitting algorithm. This method should be applicable to Thomson scattering measurements in which the signal-to-noise ratio is low due to low signal or high background. Thomson scattering data from the S-1 Spheromak have been compared to this simulation, and they have been found to be in good agreement. This code has proved to be useful assessing the effects of counting statistics relative to shot-to-shot variability in producing the observed spread in the data. It was also useful for designing improvements for the S-1 Thomson scattering system, and this method would be applicable to any measurements affected by counting statistics. 5 refs., 1 fig.

Hart, G.W.; Levinton, F.M.; McNeill, D.H.

1985-12-01

178

Strategies for Increasing the Use of Statistical Data. Occasional Paper Number 158.  

ERIC Educational Resources Information Center

This paper provides a complete picture of the environment for numeric databases and a set of appropriate responses for modifying this environment. The emphasis is on the statistical database produced by the public and private sectors, with coverage of government and academic stakeholders in the statistical data transfer system. Part one describes…

Robbin, Alice

179

Light statistics by non-calibrated linear photodetectors  

E-print Network

We theoretically demonstrate that detectors endowed with internal gain and operated in regimes in which they do not necessarily behave as photon-counters, but still ensure linear input/output responses, can allow a self-consistent characterization of the statistics of the number of detected photons without need of knowing their gain. We present experiments performed with a photo-emissive hybrid detector on a number of classical fields endowed with non-trivial statistics and show that the method works for both microscopic and mesoscopic photon numbers. The obtained detected-photon probability distributions agree with those expected for the photon numbers, which are also reconstructed by an independent method.

Maria Bondani; Alessia Allevi; Alessandra Andreoni

2008-10-22

180

Stirling Numbers of the Second Kind and Department of Mathematics and Statistics  

E-print Network

Stirling Numbers of the Second Kind and Primality Joe DeMaio Department of Mathematics Touset stephen@touset.org April 21, 2008 Abstract A Stirling number of the second kind is a combinatorial function which yields interesting number theoretic properties with regard to primality. The Stirling number

DeMaio, Joe

181

Optimum values of air-filling fraction for photonic crystal fibers with different configurations and fixed number of air rings.  

PubMed

In this study, a Gaussian amp function related to the Gaussian family is employed to approximate the output intensity profile of various arrangements of air holes in photonic crystal fibers (PCFs) with a fixed number of air rings (N=4). It is shown that d/?=0.5 can be the best minimum value of air-filling fraction for all of the studied PCFs when ?=1.35???m, whereas, for ?=1.55 and 1.65 ?m, d/?=0.6 is suitable for achieving the maximum output intensity with very low confinement loss. PMID:24663304

Zendehnam, Akbar; Hosseinpour, Maryam; Mirzaei, Mahmood; Hedayati, Kambiz

2014-02-20

182

Numbers  

NSDL National Science Digital Library

This engaging web site contains information and interactive applets related to various number systems: Egyptian, Babylonian, Chinese, Greek, Roman, Mayan, and Arabic. Users learn the history and structure of each system as well as how to count and write numbers. The site also allows users to explore finger systems, calculating machines, other number bases, and "interesting numbers." A series of pages on data and graphs includes information and activities on gathering, analyzing, graphing and sorting data. (Because the section on the Arabic number system is so extensive, it is cataloged separately as a related resource.)

Edkins, Jo

2006-01-01

183

Statistics of the scattering cross-section of a small number of random scatterers  

Microsoft Academic Search

Complex radar targets are often modeled as a number of individual scattering elements randomly distributed throughout the spatial region containing the target. While it is known that as the number of scatterers grows large the distribution of the scattered signal power or intensity is asymptotically exponential, this is not true for a small number of scatterers. The authors study the

Jihad S. Daba; Mark R. Bell

1995-01-01

184

Financial Statistics, 1980-81. Our Colleges and Universities Today. Volume XIX, Number 8.  

ERIC Educational Resources Information Center

Financial statistics for Pennsylvania colleges and universities for the fiscal year (FY) ending 1981, for 1971-1972 through 1980-1981, and for 1977-1978 through 1980-1981 are presented, along with narrative descriptions of financial trends at the institutions. Information includes the following: current-funds revenues by institutional control;…

Hottinger, Gerald W.

185

Grant Title: METHODOLOGY, MEASUREMENT, AND STATISTICS Funding Opportunity Number: NSF 12-510.  

E-print Network

-510. Agency/Department: National Science Foundation; Directorate for Social, Behavioral & Economic Sciences, Behavioral, and Economic Sciences that supports the development of innovative analytical and statistical in theory, and have potential utility for multiple fields within the social and behavioral sciences. As part

Farritor, Shane

186

Estimating the number of clusters in a dataset via the Gap statistic  

Microsoft Academic Search

We propose a method (the \\\\Gap statistic") for estimating the numberof clusters (groups) in a set of data. The technique uses the outputof any clustering algorithm (e.g. k-means or hierarchical), comparingthe change in within cluster dispersion to that expected under an appropriatereference null distribution. Some theory is developed forthe proposal and a simulation study that shows that the Gap statisticusually

Robert Tibshirani; Guenther Walther; Trevor Hastie

2000-01-01

187

New Report on the Elderly: Statistical Notes, Number 4, April 1980.  

ERIC Educational Resources Information Center

This newsletter, distributed by the National Clearinghouse on Aging, is designed to provide information about statistical programs and recent publications to the National Network on Aging as well as individuals and organizations working in the field of aging. The contents of this issue focus on: (1) a summary of estimates of the United States…

Administration on Aging (DHEW), Washington, DC.

188

Disability Statistics in the Developing World: A Reflection on the Meanings in Our Numbers  

ERIC Educational Resources Information Center

Background: The imbalance between the sheer size of the developing world and what little is known about the lives and life circumstances of persons with disabilities living there should command our attention. Method: International development initiatives routinely give great priority to the collection of statistical indicators yet even the most…

Fujiura, Glenn T.; Park, Hye J.; Rutkowski-Kmitta, Violet

2005-01-01

189

A Revelation: Quantum-Statistics and Classical-Statistics are Analytic-Geometry Conic-Sections and Numbers\\/Functions: Euler, Riemann, Bernoulli Generating-Functions: Conics to Numbers\\/Functions Deep Subtle Connections  

Microsoft Academic Search

Quantum-statistics Dichotomy: Fermi-Dirac(FDQS) Versus Bose-Einstein(BEQS), respectively with contact-repulsion\\/non-condensation(FDCR) versus attraction\\/ condensationBEC are manifestly-demonstrated by Taylor-expansion ONLY of their denominator exponential, identified BOTH as Descartes analytic-geometry conic-sections, FDQS as Elllipse (homotopy to rectangle FDQS distribution-function), VIA Maxwell-Boltzmann classical-statistics(MBCS ) to Parabola MORPHISM, VS. BEQS to Hyperbola, Archimedes' HYPERBOLICITY INEVITABILITY, and as well generating-functions[Abramowitz-Stegun, Handbook Math.-Functions--p. 804!!!], respectively of Euler-numbers\\/functions, (via Riemann

R. Descartes; G.-C. Rota; L. Euler; J. D. Bernoulli; Edward Carl-Ludwig Siegel

2011-01-01

190

Spin-Statistic Selection Rules for Multi-Equal-Photon Transitions in Atoms: Extension of the Landau-Yang Theorem to Multiphoton Systems  

E-print Network

We establish the existence of spin-statistic selection rules (SSSR) for multi-equal-photon transitions in atomic systems. These selection rules are similar to those for systems of many equivalent electrons in atomic theory. The latter ones are the direct consequence of Pauli exclusion principle. In this sense the SSSR play the role of the exclusion principle for photons: they forbid some particular states for the photon systems. We established several SSSR for few-photon systems. 1) First rule (SSSR-1): two-equivalent photons involved in any atomic transition can have only even values of the total angular momentum J. This selection rule is an extension of the Landau-Yang theorem to the photons involved in atomic transitions. 2) second rule (SSSR-2): three equivalent dipole photons involved in any atomic transition can have only odd values of the total angular momentum J=1,3. 3) third rule (SSSR-3): four equivalent dipole photons involved in any atomic transition can have only even values of the total angular ...

Zalialiutdinov, T; Labzowsky, L; Plunien, G

2014-01-01

191

Statistical independence of a new class of inversive congruential pseudorandom numbers  

Microsoft Academic Search

Linear congruential pseudorandom numbers show several undesirable regularities which can render them useless for certain stochastic simulations. This was the motivation for important recent developments in nonlinear congruential methods for generating uniform pseudorandom numbers. It is particularly promising to achieve nonlinearity by employing the operation of multiplicative inversion with respect to a prime modulus. In the present paper a new

Juergen Eichenauer-Herrmann

1993-01-01

192

Statistical independence of a new class of inversive congruential pseudorandom numbers  

Microsoft Academic Search

Linear congruential pseudorandom numbers show several undesirable regularities which can render them useless for certain stochastic simulations. This was the motiviation for important recent developments in nonlinear congruential methods for generating uniform pseudorandom numbers. It is particularly promising to achieve nonlinearity by employing the operation of multiplicative inversion with respect to a prime modulus. In the present paper a new

Jurgen Eichenauer-Herrmann

1993-01-01

193

Statistical estimations of the number of future ozone exceedances due to climate change in Europe  

NASA Astrophysics Data System (ADS)

A statistical model to examine the potential impact of increasing future temperatures due to climate change on ozone exceedances (days with daily maximum 8 h average ? 60 ppb) is developed for Europe. We employ gridded observed daily maximum temperatures and hourly ozone observations from nonurban stations across Europe, together with daily maximum temperatures for 2021-2050 and 2071-2100 from three regional climate models, based on the Intergovernmental Panel on Climate Change Special Reports on Emissions Scenarios A1B scenario. A rotated principal components analysis is applied to the ozone stations yielding five principal components, which divide the study domain in five subregions. The historical ozone-temperature relationship is examined and then used to provide estimates of future ozone exceedance days under current emissions and under the assumption that this relationship will retain its main characteristics. Results suggest that increases in the upper temperature percentiles lead to statistically significant increases (95% statistical significance level) of the ozone exceedances for both future periods. The greatest average increases depending on the particular regional climate model range from 5 to 12 extra ozone days/yr for 2021-2050 and from 16 to 25 for 2071-2100, in southeast Europe. The lowest average increases range from 0 to 2 extra ozone days/yr for 2021-2050 and from 2 to 4 for 2071-2100 and are seen in northwest Europe. The simulations with the dynamical Goddard Institute of Space Studies/GEOS-CHEM climate chemistry modeling system shows decreases instead of increases in eastern Europe, higher increases in northwest Europe, whereas for the other subregions similar results to the statistical model are obtained.

Varotsos, K. V.; Tombrou, M.; Giannakopoulos, C.

2013-06-01

194

Getting the numbers right: statistical mischief and racial profiling in heart failure research.  

PubMed

The claim that blacks die from heart failure at a rate twice that of whites is informing efforts to develop and market the drug BiDil, which is currently undergoing clinical trials to be approved by the FDA as the first drug ever specified to treat African Americans--and only African Americans--for heart failure. The drug and its companion statistic have since come to play prominent roles in debates about so-called "racial profiling" in medicine and the legitimacy of using social categories of race in biomedical research. Nonetheless, this statistic is wrong. The most current data available place the black:white mortality ratio for heart failure at approximately 1.1:1. The article tells the story of attempts to get to the source of the supposed 2:1 mortality ratio and explores some of the implications of the acceptance of these erroneous data, both for the allocation of resources to combat disease and for our broader understanding of the nature and meaning of race. PMID:14593217

Kahn, Jonathan

2003-01-01

195

SCHOOL OF MATHEMATICS AND STATISTICS Autumn Semester Topics in Number Theory (Level 2) 2 hours  

E-print Network

Wilson's theorem.) (6 marks) 2 (i) State the Law of Quadratic Reciprocity. (2 marks) (ii) Use the Law. If it has, solve it. (10 marks) (iii) Use the Law of Quadratic Reciprocity to prove that, for a prime number of Quadratic Reciprocity to determine whether the congruence 2x2 + 5x - 9 0 (mod 101) has a solution

196

Quantum number conservation in the statistical bootstrap of fireball decay spectra  

Microsoft Academic Search

Quantum number conservation is considered within the stastistical ; bootstrap model by generalizing the bootstrap equation for the generating ; functional of fireball decay spectra. Explicit solutions are given for the level ; density and the generating functional in the case of additive quantum nunnbers as ; well as isospin conservation. Asymptotic expressions for the level density, the ; inclusive

E. M. Ilgenfritz; J. Kripfganz

1973-01-01

197

A Statistical Analysis for Estimating Fish Number Density with the Use of a Multibeam Echosounder  

NASA Astrophysics Data System (ADS)

Fish number density can be estimated from the normalized second moment of acoustic backscatter intensity [Denbigh et al., J. Acoust. Soc. Am. 90, 457-469 (1991)]. This method assumes that the distribution of fish scattering amplitudes is known and that the fish are randomly distributed following a Poisson volume distribution within regions of constant density. It is most useful at low fish densities, relative to the resolution of the acoustic device being used, since the estimators quickly become noisy as the number of fish per resolution cell increases. New models that include noise contributions are considered. The methods were applied to an acoustic assessment of juvenile Atlantic Bluefin Tuna, Thunnus thynnus. The data were collected using a 400 kHz multibeam echo sounder during the summer months of 2009 in Cape Cod, MA. Due to the high resolution of the multibeam system used, the large size (approx. 1.5 m) of the tuna, and the spacing of the fish in the school, we expect there to be low fish densities relative to the resolution of the multibeam system. Results of the fish number density based on the normalized second moment of acoustic intensity are compared to fish packing density estimated using aerial imagery that was collected simultaneously.

Schroth-Miller, Madeline L.

198

Statistical and functional representations of the pattern of auroral energy flux, number flux, and conductivity  

SciTech Connect

Global patterns of the integral energy flux and average energy of precipitating auroral electrons are used to determine the global pattern of the electron-produced, height-integrated Hall and Pedersen conductivities. The conductivities were determined in spatial bins in magnetic local time (MLT)-corrected geomagnetic latitude (CGL) coordinates for all MLTs and for CGLs greater than 50 deg and for seven levels of activity as measured by Kp. On the nightside the two conductivities increase with increasing Kp. The largest conductivities are found near midnight, where the peak value of the Pedersen (Hall) conductivity varies from 3.09 (4.05) mhos to 12.5 (25.9) mhos as Kp varies from 0 > or = 6-. At noon and on much of morning side of the oval the Pedersen and Hall conductivities increase for Kp up to 2 and then decrease for higher Kp. The highest ratios of the Hall to Pedersen conductivity are on the morning side of the oval and at noon. The peak conductivities on the dayside are significant compared to the conductivities produced by solar radiation at all seasons of the year. The global maps of the integral energy flux, integral number flux, and height-integrated Hall and Pedersen conductivities at each level of Kp were fit using both spherical harmonic and Epstein functions. The Epstein functions were found to reproduce better the original maps. At Kp = 2 the distribution of differences between the Epstein function fit and the original data is roughly symmetric about zero with a full width at half maximum of 16 (20)% for the Pedersen (Hall) conductivity and 32(40)% for the integral energy (number) flux. The distribution of difference broadens with increasing and decreasing activity.

Hardy, D.A.; Gussenhoven, M.S.; Raistrick, R.

1987-11-01

199

Statistical and functional representations of the pattern of auroral energy flux, number flux, and conductivity  

SciTech Connect

The Hardy et al. (1985) global patterns of the the integral energy flux and average energy of precipitating auroral electrons are used to determine the global pattern of electron-produced, height-integrated Hall and Pedersen conductivities. THe conductivities were determined in spatial bins in magnetic local time (MLT)-corrected geomagnetic latitude (CGL) coordinates for all MLTs and for CGLs greater than 50/sup 0/ and for sevel levels of activity as measured by Kp. The conductivities vary smoothly with latitude and MLT typically having a single peak in latitude within the auroral oval at any MLT. On the nightside the two conductivities increase with increasing Kp. The largest conductivities are found near midnight, where the peak value of the Pederson (Hall) conductivity varies from 3.09 (4.05) mhos to 12.5 (25.9) mhos as Kp varies from 0 to greater than or equal to6-. The peak conductivity decreases with MLT away from midnight with the lowest peak values found postnoon. At noon and on much of the morning side of the oval the Pedersen and Hall conductivities increase for Kp up to 2 and then decrease for higher Kp. The highest ratios of the Hall to Petersen conductivity are on the morning side of the oval and at noon. The peak conductivities on the dayside are significant compared to the conductivities produced by solar radiation at all seasons of the year. The global maps of the integral energy flux, integral number flux, and height-integrated Hall and Pedersen conductivities at each level of Kp were fit using both spherical harmonic and Epstein functions. The Epstein functions were found to reproduce better the original maps.

Hardy, D.A.; Gussenhoven, M.S.; Raistrick, R.; McNeil, W.J.

1987-11-01

200

Statistical and hydrodynamic properties of double-ring polymers with a fixed linking number between twin rings  

NASA Astrophysics Data System (ADS)

For a double-ring polymer in solution we evaluate the mean-square radius of gyration and the diffusion coefficient through simulation of off-lattice self-avoiding double polygons consisting of cylindrical segments with radius rex of unit length. Here, a self-avoiding double polygon consists of twin self-avoiding polygons which are connected by a cylindrical segment. We show numerically that several statistical and dynamical properties of double-ring polymers in solution depend on the linking number of the constituent twin ring polymers. The ratio of the mean-square radius of gyration of self-avoiding double polygons with zero linking number to that of no topological constraint is larger than 1, in particular, when the radius of cylindrical segments rex is small. However, the ratio is almost constant with respect to the number of vertices, N, and does not depend on N. The large-N behavior of topological swelling is thus quite different from the case of knotted random polygons.

Uehara, Erica; Deguchi, Tetsuo

2014-01-01

201

Studies on effective atomic numbers for photon energy absorption and electron density of some narcotic drugs in the energy range 1 keV-20 MeV  

NASA Astrophysics Data System (ADS)

Effective atomic numbers for photon energy absorption ZPEA,eff, photon interaction ZPI,eff and for electron density Nel, have been calculated by a direct method in the photon-energy region from 1 keV to 20 MeV for narcotic drugs, such as Heroin (H), Cocaine (CO), Caffeine (CA), Tetrahydrocannabinol (THC), Cannabinol (CBD), Tetrahydrocannabivarin (THCV). The ZPEA,eff, ZPI,eff and Nel values have been found to change with energy and composition of the narcotic drugs. The energy dependence ZPEA,eff, ZPI,eff and Nel is shown graphically. The maximum difference between the values of ZPEA,eff, and ZPI,eff occurs at 30 keV and the significant difference of 2 to 33% for the energy region 5-100 keV for all drugs. The reason for these differences is discussed.

Gounhalli, Shivraj G.; Shantappa, Anil; Hanagodimath, S. M.

2013-04-01

202

The local enhancement of radiation dose from photons of MeV energies obtained by introducing materials of high atomic number into the treatment region.  

PubMed

With the advent of therapeutic radiation treatment machines with photon end point energies of several MeV, a new channel is available to transfer the photon energy to biological material, namely, pair production. This process has a photon threshold energy of 1.02 MeV. The probability of pair production, which depends on the square of the atomic number (Z) of the interacting material, increases markedly as the photon energy is further increased. As the goal of treatment planning in radiation therapy is to locally maximize the absorbed dose in abnormal cells and minimize the dose in surrounding normal cells, in this study the authors measured the dose enhancement which could be expected if a high-Z material such as gold was present adjacent to tumor sites during irradiation. The authors used photon beams produced by electron accelerators with energies ranging from 6 to 25 MV. They chose either gold or lead foils as high-Z materials, the measurements being repeated using the same geometry but replacing the high-Z materials with a low-Z material (aluminum). The comparison of the experimental results using low- and high-Z materials verified the theoretical prediction of the expected dose enhancement. The effect of finite range of the electron-positron pairs was also studied by varying the spacing between two foils placed parallel or orthogonal to the incident photon beam. Using an 18 MV photon beam, the authors observed a maximum dose enhancement of 44%. They intend therefore to proceed from these phantom studies to animal measurements. PMID:19746788

Alkhatib, Ahmad; Watanabe, Yoichi; Broadhurst, John H

2009-08-01

203

On the Poisson Approximation to Photon Distribution for Faint Lasers Yucheng Hua  

E-print Network

On the Poisson Approximation to Photon Distribution for Faint Lasers Yucheng Hua , Xiang Pengb statistics for attenuated faint laser pulses is quantitatively studied. It confirms that, even for a non-Poissonian laser source, after being attenuated into faint laser with ultra-low mean photon number, the photon

Lu, Tiao

204

A new approach to mathematical statistics involving the number of degrees of freedom, temperature, and symplectically conjugate quantities  

NASA Astrophysics Data System (ADS)

We introduce several new notions in mathematical statistics that bridge the gap between this discipline and statistical physics. The analogy between them is useful both for mathematics and for physics. What is more, this new mathematical statistics is adequate for the study of computer networks and self-teaching systems. The role of the web in sociological and economic research is ascertained.

Maslov, V. P.; Maslova, T. V.

2013-07-01

205

Exposure to Alcoholism in the Family: United States, 1988. Advance Data from Vital and Health Statistics of the National Center for Health Statistics. Number 205.  

ERIC Educational Resources Information Center

This report is based on data from the 1988 National Health Interview Survey on Alcohol (NHIS-Alcohol), part of the ongoing National Health Interview Survey conducted by the National Center for Health Statistics. Interviews for the NHIS are conducted in person by staff of the United States Bureau of the Census. Information is collected on each…

Schoenborn, Charlotte A.

206

TRANS-STAT: statistics for environmental studies, Number 16. Extreme value statistics applied to environmental radionuclide studies: Chapters 7 and 8  

SciTech Connect

The commonly used procedure for estimating the Extreme Value distribution of a sequence of measurements implicitly assumes the samples are from a stationary random process. This ignores the well known systematic and cyclic trends that typically occur. Ignoring these trends tends to overestimate the magnitude of the extremes and their associated statistics. This chapter has presented a procedure for including such trends within the parameter estimation algorithm. The result is a better estimate of extreme values.

Gilbert, R.O.; Kinnison, R.R.

1981-08-01

207

A direct method of particle sizing based on the statistical processing of scattered photons from particles executing Brownian motion  

Microsoft Academic Search

A direct method of determining the mean diameter of particles executing Brownian motion is presented. The temporal coherence of the scattered field from submicroscopic particles illuminated by laser light is a function of both the integration time and the particle diameter. The temporal degree of coherence of the time-averaged scattered intensity decreases as the integration time increases. Statistical processing of

H. S. Dhadwal; K. Suh; D. A. Ross

1996-01-01

208

Determination of confidence limits for experiments with low numbers of counts. [Poisson-distributed photon counts from astrophysical sources  

NASA Technical Reports Server (NTRS)

Two different methods, classical and Bayesian, for determining confidence intervals involving Poisson-distributed data are compared. Particular consideration is given to cases where the number of counts observed is small and is comparable to the mean number of background counts. Reasons for preferring the Bayesian over the classical method are given. Tables of confidence limits calculated by the Bayesian method are provided for quick reference.

Kraft, Ralph P.; Burrows, David N.; Nousek, John A.

1991-01-01

209

A Statistical Study of the Public Schools of the Southern Appalachian Mountains. Bulletin, 1915, No. 11. Whole Number 636  

ERIC Educational Resources Information Center

Information concerning educational conditions in the southern Appalachian region is scattered, fragmentary, and often partisan to the assumption either that conditions are ideal or that they are inconceivably bad. The purpose of this study is to draw together the available facts in the case. Necessarily, this study is largely statistical. The…

Frost, Norman

1915-01-01

210

Photon counting spectroscopy as done with a Thomson scattering diagnostic  

SciTech Connect

The measurement and reduction of photon counting spectral data is demonstrated within the context of a Thomson scattering diagnostic. This diagnostic contains a microchannel plate (MCP) photomultiplier tube (PMT) as the photon sensing device. The MCP PMT is not an ideal photon sensor, the loss of photoelectrons at the MCP input and the broad charge pulse distribution at the output add to the uncertainty in recorded data. Computer simulations are used to demonstrate an approach to quantification of this added uncertainty and to develop an understanding of its source; the methodology may be applicable to the development of an understanding of photon detectors other than an MCP PMT. Emphasis is placed on the Poisson statistical character of the data, because the assumption that a Gaussian probability distribution is a reasonable statistical description of photon counting data is often questionable. When the count rate is low, the product the possible number of photon counts and the probability of measurement of a single photon is usually not sufficiently large to justify Gaussian statistics. Rather, because probabilities of measurement are so low, the Poisson probability distribution best quantifies the inherent statistical fluctuations in such counting measurements. The method of maximum likelihood is applied to derive the Poisson statistics equivalent of {sub X}{sup 2}. A Poisson statistics based data fitting code is implemented using the Newton-Raphson method of multi-dimensional root finding; we also demonstrate an algorithm to estimate the uncertainties in derived quantities.

Den Hartog, D.J.; Ruppert, D.E.

1993-11-01

211

Two-state theory of binned photon statistics for a large class of waiting time distributions and its application to quantum dot blinking.  

PubMed

A theoretical method is proposed for the calculation of the photon counting probability distribution during a bin time. Two-state fluorescence and steady excitation are assumed. A key feature is a kinetic scheme that allows for an extensive class of stochastic waiting time distribution functions, including power laws, expanded as a sum of weighted decaying exponentials. The solution is analytic in certain conditions, and an exact and simple expression is found for the integral contribution of "bright" and "dark" states. As an application for power law kinetics, theoretical results are compared with experimental intensity histograms from a number of blinking CdSe/ZnS quantum dots. The histograms are consistent with distributions of intensity states around a "bright" and a "dark" maximum. A gap of states is also revealed in the more-or-less flat inter-peak region. The slope and to some extent the flatness of the inter-peak feature are found to be sensitive to the power-law exponents. Possible models consistent with these findings are discussed, such as the combination of multiple charging and fluctuating non-radiative channels or the multiple recombination center model. A fitting of the latter to experiment provides constraints on the interaction parameter between the recombination centers. Further extensions and applications of the photon counting theory are also discussed. PMID:24929377

Volkán-Kacsó, Sándor

2014-06-14

212

Role of Initial Entanglement and Non-Gaussianity in the Decoherence of Photon-Number Entangled States Evolving in a Noisy Channel  

NASA Astrophysics Data System (ADS)

We address the degradation of continuous variable (CV) entanglement in a noisy channel focusing on the set of photon-number entangled states. We exploit several separability criteria and compare the resulting separation times with the value of non-Gaussianity at any time, thus showing that in the low-temperature regime: (i) non-Gaussianity is a bound for the relative entropy of entanglement and (ii) Simon’s criterion provides a reliable estimate of the separation time also for non-Gaussian states. We provide several evidences supporting the conjecture that Gaussian entanglement is the most robust against noise, i.e., it survives longer than a non-Gaussian one, and that this may be a general feature for CV systems in Markovian channels.

Allegra, Michele; Giorda, Paolo; Paris, Matteo G. A.

2010-09-01

213

How to handle gender and number agreement in statistical language models? Caroline Lavecchia, Kamel Smaili and Jean-Paul Haton  

E-print Network

estimates the probability of a word from its recent frequency of use. P(wi) = 1 N N j=1 (wi, wj) (1) where N an original model called Features-Cache (FC) to estimate the gender and the number of the word to predict of the main difficulties in speech recognition of French language is the presence of misrecognized words due

Paris-Sud XI, Université de

214

Statistical Studies on Protein Polymorphism in Natural Populations. III. Distribution of Allele Frequencies and the Number of Alleles per Locus  

PubMed Central

With the aim of understanding the mechanism of maintenance of protein polymorphism, we have studied the properties of allele frequency distribution and the number of alleles per locus, using gene-frequency data from a wide range of organisms (mammals, birds, reptiles, amphibians, Drosophila and non-Drosophila invertebrates) in which 20 or more loci with at least 100 genes were sampled. The observed distribution of allele frequencies was U-shaped in all of the 138 populations (mostly species or subspecies) examined and generally agreed with the theoretical distribution expected under the mutation-drift hypothesis, though there was a significant excess of rare alleles (gene frequency, 0 ? 0.05) in about a quarter of the populations. The agreement between the mutation-drift theory and observed data was quite satisfactory for the numbers of polymorphic (gene frequency, 0.05 ? 0.95) and monomorphic (0.95 ? 1.0) alleles.—The observed pattern of allele-frequency distribution was incompatible with the prediction from the overdominance hypothesis. The observed correlations of the numbers of rare alleles, polymorphic alleles and monomorphic alleles with heterozygosity were of the order of magnitude that was expected under the mutation-drift hypothesis. Our results did not support the view that intracistronic recombination is an important source of genetic variation. The total number of alleles per locus was positively correlated with molecular weight in most of the species examined, and the magnitude of the correlation was consistent with the theoretical prediction from mutation-drift hypothesis. The correlation between molecular weight and the number of alleles was generally higher than the correlation between molecular weight and heterozygosity, as expected. PMID:17249018

Chakraborty, Ranajit; Fuerst, Paul A.; Nei, Masatoshi

1980-01-01

215

Protein stability by number: high-throughput and statistical approaches to one of protein science's most difficult problems.  

PubMed

Most proteins are only barely stable, which impedes research, complicates therapeutic applications, and makes proteins susceptible to pathologically destabilizing mutations. Our ability to predict the thermodynamic consequences of even single point mutations is still surprisingly limited, and established methods of measuring stability are slow. Recent advances are bringing protein stability studies into the high-throughput realm. Some methods are based on inferential read-outs such as activity, proteolytic resistance or split-protein fragment reassembly. Other methods use miniaturization of direct measurements, such as intrinsic fluorescence, H/D exchange, cysteine reactivity, aggregation and hydrophobic dye binding (DSF). Protein engineering based on statistical analysis (consensus and correlated occurrences of amino acids) is promising, but much work remains to understand and implement these methods. PMID:21498105

Magliery, Thomas J; Lavinder, Jason J; Sullivan, Brandon J

2011-06-01

216

Photon Clusters in Thermal Radiation  

E-print Network

Within the framework of Bose-Einstein statistics, it is shown that the blackbody radiation, in addition to single photons, contains photon clusters, or coalescent photons. The probability to find a k-photon cluster versus radiation frequency and temperature is found, as well as the statistics of clusters. Spectra of photon-cluster radiation are calculated as functions of blackbody temperature. The Planck's radiation law is derived based on the existence of photon clusters. The possibility of experimental observation of photon clusters in thermal radiation is discussed.

Aleksey Ilyin

2014-10-30

217

Optimization of periodic single-photon sources  

E-print Network

We introduce a theoretical framework which is suitable for the description of all spatial and time-multiplexed periodic single-photon sources realized or proposed thus far. Our model takes into account all possibly relevant loss mechanisms. This statistical analysis of the known schemes shows that multiplexing systems can be optimized in order to produce maximal single-photon probability for various sets of loss parameters by the appropriate choice of the number of multiplexed units of spatial multiplexers or multiplexed time intervals and the input mean photon pair number, and reveals the physical reasons of the existence of the optimum. We propose a novel time-multiplexed scheme to be realized in bulk optics, which, according to the present analysis, would have promising performance when experimentally realized. It could provide a single-photon probability of 85\\% with a choice of experimental parameters which are feasible according to the experiments known from the literature.

Peter Adam; Matyas Mechler; Imre Santa; Mátyás Koniorczyk

2014-08-14

218

Discrimination of three tobacco types (Burley, Virginia and Oriental) by pyrolysis single-photon ionisation-time-of-flight mass spectrometry and advanced statistical methods.  

PubMed

Pyrolysis single-photon ionisation (SPI)-time-of-flight mass spectrometry (TOFMS) and statistical analysis techniques have been applied to differentiate three major tobacco types, Burley, Virginia and Oriental, by means of the gas phase. SPI is known as a soft ionisation technique that allows fast and comprehensive on-line monitoring of a large variety of aliphatic and aromatic substances without fragmentation of the molecule ions. The tobacco samples were pyrolysed at 800 degrees C in a nitrogen atmosphere. The resulting pyrolysis gas contained signals from more than 70 masses between m/z 5 and 170. Mass spectra obtained were analysed by principal component analysis (PCA) and linear discriminant analysis (LDA) to distinguish between different tobacco types. Prior variable reduction of the data set was carried out by calculation of the Fisher ratios. Results achieved give information about chemical composition and characteristics of the smoke derived from each tobacco type and enable conclusions on plant cultivation to be drawn. Based on LDA, a model for tobacco type recognition of unknown samples was established, which was cross-checked by additional measurements of each tobacco type. Furthermore, first results on the recognition of tobacco mixtures based on principal component regression (PCR) are presented. PMID:15599713

Adam, T; Ferge, T; Mitschke, S; Streibel, T; Baker, R R; Zimmermann, R

2005-01-01

219

Photon-Photon Colliders  

E-print Network

pairs of particles are produced. In photon-photon colliders.PARTICLE PHYSICS AND EXPERIMENTAL DETECfORSt The Structure functions of the photon,Particle Accelerator Conference 1995, Dallas, TX, May 1-5, 1995, and to be published in the Proceedings Photon-

Sessler, Andrew M.

2008-01-01

220

Photonic quantum well composed of photonic crystal and quasicrystal  

NASA Astrophysics Data System (ADS)

A photonic quantum well structure composed of photonic crystal and Fibonacci quasicrystal is investigated by analyzing the transmission spectra and electric field distributions. The defect band in the photonic well can form confined quantized photonic states that can change in the band-gap of the photonic barriers by varying the thickness ratio of the two stacking layers. The number of confined states can be tuned by adjusting the period of the photonic well. The photons traverse the photonic quantum well by resonance tunneling and the coupling effect leads to the high transmission intensity of the confined photonic states.

Xu, Shaohui; Zhu, Yiping; Wang, Lianwei; Yang, Pingxiong; Chu, Paul K.

2014-02-01

221

Bright integrated photon-pair source for practical passive decoy-state quantum key distribution  

NASA Astrophysics Data System (ADS)

We report on a bright, nondegenerate type-I parametric down-conversion source, which is well suited for passive decoy-state quantum key distribution. We show the photon-number-resolved analysis over a broad range of pump powers and we prove heralded higher-order n-photon states up to n =4. The inferred photon click statistics exhibit excellent agreements to the theoretical predictions. From our measurement results we conclude that our source meets the requirements to avert photon-number-splitting attacks.

Krapick, S.; Stefszky, M. S.; Jachura, M.; Brecht, B.; Avenhaus, M.; Silberhorn, C.

2014-01-01

222

Bright Integrated Photon-Pair Source for Practical Passive Decoy-State Quantum Key Distribution  

E-print Network

We report on a bright, nondegenerate type-I parametric down-conversion source, which is well suited for passive decoy-state quantum key distribution. We show the photon-number-resolved analysis over a broad range of pump powers and we prove heralded higher-order $n$-photon states up to $n=4$. The inferred photon click statistics exhibit excellent agreements to the theoretical predictions. From our measurement results we conclude that our source meets the requirements to avert photon-number-splitting attacks.

Stephan Krapick; Michael Stefszky; Michal Jachura; Benjamin Brecht; Malte Avenhaus; Christine Silberhorn

2014-01-28

223

Photon position measure  

SciTech Connect

The positive operator valued measure (POVM) for a photon counting array detector is derived and found to equal photon flux density integrated over pixel area and measurement time. Since photon flux density equals number density multiplied by the speed of light, this justifies theoretically the observation that a photon counting array provides a coarse-grained measurement of photon position. The POVM obtained here can be written as a set of projectors onto a basis of localized states, consistent with the description of photon position in a recent quantum imaging proposal [Tsang, Phys. Rev. Lett. 102, 253601 (2009)]. The wave function that describes a photon counting experiment is the projection of the photon state vector onto this localized basis. Collapse is to the electromagnetic vacuum and not to a localized state, thus violating the textbook rules of quantum mechanics but compatible with the theory of generalized observables and the nonlocalizability of an incoming photon.

Hawton, Margaret [Department of Physics, Lakehead University, Thunder Bay, Ontario, P7B 5E1 (Canada)

2010-07-15

224

Equivalence between fractional exclusion statistics and self-consistent mean-field theory in interacting-particle systems in any number of dimensions.  

PubMed

We describe a mean field interacting particle system in any number of dimensions and in a generic external potential as an ideal gas with fractional exclusion statistics (FES). We define the FES quasiparticle energies, we calculate the FES parameters of the system and we deduce the equations for the equilibrium particle populations. The FES gas is "ideal," in the sense that the quasiparticle energies do not depend on the other quasiparticle levels' populations and the sum of the quasiparticle energies is equal to the total energy of the system. We prove that the FES formalism is equivalent to the semiclassical or Thomas Fermi limit of the self-consistent mean-field theory and the FES quasiparticle populations may be calculated from the Landau quasiparticle populations by making the correspondence between the FES and the Landau quasiparticle energies. The FES provides a natural semiclassical ideal gas description of the interacting particle gas. PMID:24229158

Anghel, D V; Nemnes, G A; Gulminelli, F

2013-10-01

225

RANDOMNESS of Numbers DEFINITION(QUERY:WHAT? V HOW?) ONLY Via MAXWELL-BOLTZMANN CLASSICAL-Statistics(MBCS) Hot-Plasma VS. Digits-Clumping Log-Law NON-Randomness Inversion ONLY BOSE-EINSTEIN QUANTUM-Statistics(BEQS) .  

NASA Astrophysics Data System (ADS)

RANDOMNESS of Numbers cognitive-semantics DEFINITION VIA Cognition QUERY: WHAT???, NOT HOW?) VS. computer-"science" mindLESS number-crunching (Harrel-Sipser-...) algorithmics Goldreich "PSEUDO-randomness"[Not.AMS(02)] mea-culpa is ONLY via MAXWELL-BOLTZMANN CLASSICAL-STATISTICS(NOT FDQS!!!) "hot-plasma" REPULSION VERSUS Newcomb(1881)-Weyl(1914;1916)-Benford(1938) "NeWBe" logarithmic-law digit-CLUMPING/ CLUSTERING NON-Randomness simple Siegel[AMS Joint.Mtg.(02)-Abs. # 973-60-124] algebraic-inversion to THE QUANTUM and ONLY BEQS preferentially SEQUENTIALLY lower-DIGITS CLUMPING/CLUSTERING with d = 0 BEC, is ONLY VIA Siegel-Baez FUZZYICS=CATEGORYICS (SON OF TRIZ)/"Category-Semantics"(C-S), latter intersection/union of Lawvere(1964)-Siegel(1964)] category-theory (matrix: MORPHISMS V FUNCTORS) "+" cognitive-semantics" (matrix: ANTONYMS V SYNONYMS) yields Siegel-Baez FUZZYICS=CATEGORYICS/C-S tabular list-format matrix truth-table analytics: MBCS RANDOMNESS TRUTH/EMET!!!

Siegel, Z.; Carl-Ludwig Siegel, Edward

2011-03-01

226

Statistics Tools  

NSDL National Science Digital Library

This collection of calculators, created by Thomas Kirkman of the College of Saint Bendict/Saint Joseph, allows users to perform a number of statistical applications. Each provides background on the procedure and an example. Users can compute descriptive statistics and perform t-tests, Chi-square tests, Kolmogorov-Smirnov tests, Fisher's Exact Test, contingency tables, ANOVA, and regression. This is a nice collection of useful applications for a statistics classroom.

Kirkman, Thomas

2009-02-04

227

Photon Wave Mechanics  

E-print Network

In contrast to wave functions in nonrelativistic quantum mechanics interpreted as probability amplitudes, wave functions in relativistic quantum mechanics have generalized meanings such as charge-density amplitudes, energy-density amplitudes as well as particle-number density amplitudes, etc. Applying electromagnetic field intensities we construct a photon wave function, it corresponds to the (1,0)+(0,1) spinor representation of the electromagnetic field, and can be interpreted as the energy-density amplitude of photons outside a source. In terms of photon wave functions we develop photon wave mechanics, which provides us with a new quantum-mechanical description for photons outside a source.

Zhi-Yong Wang; Cai-Dong Xiong; Ole Keller

2005-11-18

228

Quantum nonlinear optics -- photon by photon  

NASA Astrophysics Data System (ADS)

The realization of strong interactions between individual photons is a long-standing goal of both fundamental and technological significance. Scientists have known for over half a century that light fields can interact inside nonlinear optical media, but the nonlinearity of conventional materials is negligible at the light powers associated with individual photons. Nevertheless, remarkable advances in quantum optics have recently culminated in the demonstration of several methods for generating optical nonlinearities at the level of individual photons. Systems exhibiting strong photon-photon interactions enable a number of unique applications, including quantum-by-quantum control of light fields, single-photon switches and transistors, all-optical deterministic quantum logic, and the realization of strongly correlated states of light and matter.

Chang, Darrick E.; Vuleti?, Vladan; Lukin, Mikhail D.

2014-09-01

229

Photon-photon collisions  

SciTech Connect

Highlights of the VIIIth International Workshop on Photon-Photon Collisions are reviewed. New experimental and theoretical results were reported in virtually every area of ..gamma gamma.. physics, particularly in exotic resonance production and tests of quantum chromodynamics where asymptotic freedom and factorization theorems provide predictions for both inclusive and exclusive ..gamma gamma.. reactions at high momentum transfer. 73 refs., 12 figs.

Brodsky, S.J.

1988-07-01

230

The 2009 Berkeley Mini Statistical Mechanics Meeting January 9-11, 2009 ** Please note, the order listed corresponds to the poster board number as well as the  

E-print Network

The 2009 Berkeley Mini Statistical Mechanics Meeting January 9-11, 2009 ** Please note, the order Berkeley Mini Statistical Mechanics Meeting January 9-11, 2009 ** Please note, the order listed corresponds to protein-ligand binding" Schedule of Poster Presentations #12;The 2009 Berkeley Mini Statistical Mechanics

Chandler, David

231

STATISTICAL METHODS STATISTICAL METHODS  

E-print Network

STATISTICAL METHODS 1 STATISTICAL METHODS Arnaud Delorme, Swartz Center for Computational@salk.edu. Keywords: statistical methods, inference, models, clinical, software, bootstrap, resampling, PCA, ICA Abstract: Statistics represents that body of methods by which characteristics of a population are inferred

Delorme, Arnaud

232

Hybrid laser with CMOS photonics  

E-print Network

In this thesis, an interesting approach for a photonic laser source is presented. By using integrated photonic resonators with an external gain medium, we are able to build a laser that offers a number of advantages including ...

Chong, Johanna S

2014-01-01

233

Statistics of multiphoton events in spontaneous parametric down-conversion  

E-print Network

We present an experimental characterization of the statistics of multiple photon pairs produced by spontaneous parametric down-conversion realized in a nonlinear medium pumped by high-energy ultrashort pulses from a regenerative amplifier. The photon number resolved measurement has been implemented with the help of a fiber loop detector. We introduce an effective theoretical description of the observed statistics based on parameters that can be assigned direct physical nterpretation. These parameters, determined for our source from the collected experimental data, characterize the usefulness of down-conversion sources in multiphoton interference schemes that underlie protocols for quantum information processing and communication.

Wojciech Wasilewski; Czeslaw Radzewicz; Robert Frankowski; Konrad Banaszek

2008-05-12

234

On the Poisson Approximation to Photon Distribution for Faint Lasers  

E-print Network

It is proved, that for a certain kind of input distribution, the strongly binomially attenuated photon number distribution can well be approximated by a Poisson distribution. This explains why we can adopt poissonian distribution as the photon number statistics for faint lasers. The error of such an approximation is quantitatively estimated. Numerical tests are carried out, which coincide with our theoretical estimations. This work lays a sound mathematical foundation for the well-known intuitive idea which has been widely used in quantum cryptography.

Yucheng Hu; Xiang Peng; Tiejun Li; Hong Guo

2006-09-23

235

Synthetic Estimation of State Health Characteristics Based on the Health Interview Survey. Vital and Health Statistics. Series 2. Data Evaluation and Methods Research. Number 75.  

ERIC Educational Resources Information Center

Synthetic estimation is a statistical technique that estimates small-area statistics by combining national estimates of the relevant characteristics with estimates of other known characteristics of the small geographic area. The advantages of the synthetic estimation approach to local estimation are its intuitive appeal, its simplicity, and its…

Levy, Paul S.; French, Dwight K.

236

Number Watch  

NSDL National Science Digital Library

John Brignell, Professor Emeritus from the Department of Electronics & Computer Science at the University of Southampton, is the author of this informal website "devoted to the monitoring of the misleading numbers that rain down on us via the media." Brignell says he aims to "nail" a few of the "Single Issue Fanatics (SIFs), politicians, bureaucrats, quasi-scientists (junk, pseudo- or just bad)," who use misleading numbers to write catchy articles or who try to keep numbers away from public notice. Since April 2000, he has been posting a "number of the month" as well as a "number for the year," which offer his commentary on media usage of misleading numbers and explanations for why the numbers are misleading. He also posts book reviews and an extensive list of online resources on statistics and statistics education. The FAQ section includes answers to some interesting questions, such as "Is there such a thing as average global temperature?" and some more basic questions such as "What is the Normal Distribution and what is so normal about it?" The Bits and Pieces section includes a variety of short articles on statistics and his definitions for some terms he uses on the website. Visitors are also invited to join the discussion forum (complete with a few advertisements) and view comments by others who want to discuss "wrong numbers in science, politics and the media." A few comments sent to Brignell and his responses are also posted online. This site is also reviewed in the February 11, 2005_NSDL MET Report_.

237

Photon calorimeter  

DOEpatents

A photon calorimeter is provided that comprises a laminar substrate that is uniform in density and homogeneous in atomic composition. A plasma-sprayed coating, that is generally uniform in density and homogeneous in atomic composition within the proximity of planes that are parallel to the surfaces of the substrate, is applied to either one or both sides of the laminar substrate. The plasma-sprayed coatings may be very efficiently spectrally tailored in atomic number. Thermocouple measuring junctions, are positioned within the plasma-sprayed coatings. The calorimeter is rugged, inexpensive, and equilibrates in temperature very rapidly. 4 figs.

Chow, Tze-Show

1988-04-22

238

Photon pair correlation spectroscopy of single tetrahedraloligophenylenevinylene molecules at room temperature  

E-print Network

Photon pair correlation spectroscopy of single tetrahedraloligophenylenevinylene molecules at room the photon statistics of single tetrahedral based oligophenylenevinylene (TOPV) molecules using photon pair tetrahedral molecule contain more than one excited chromophore and emit two or more photons simultaneously

Buratto, Steve

239

Photonic Aharonov-Bohm effect in photon-phonon interactions  

NASA Astrophysics Data System (ADS)

The Aharonov-Bohm effect is one of the most intriguing phenomena in both classical and quantum physics, and associates with a number of important and fundamental issues in quantum mechanics. The Aharonov-Bohm effects of charged particles have been experimentally demonstrated and found applications in various fields. Recently, attention has also focused on the Aharonov-Bohm effect for neutral particles, such as photons. Here we propose to utilize the photon-phonon interactions to demonstrate that photonic Aharonov-Bohm effects do exist for photons. By introducing nonreciprocal phases for photons, we observe experimentally a gauge potential for photons in the visible range based on the photon-phonon interactions in acousto-optic crystals, and demonstrate the photonic Aharonov-Bohm effect. The results presented here point to new possibilities to control and manipulate photons by designing an effective gauge potential.

Li, Enbang; Eggleton, Benjamin J.; Fang, Kejie; Fan, Shanhui

2014-01-01

240

Photonic Aharonov-Bohm effect in photon-phonon interactions.  

PubMed

The Aharonov-Bohm effect is one of the most intriguing phenomena in both classical and quantum physics, and associates with a number of important and fundamental issues in quantum mechanics. The Aharonov-Bohm effects of charged particles have been experimentally demonstrated and found applications in various fields. Recently, attention has also focused on the Aharonov-Bohm effect for neutral particles, such as photons. Here we propose to utilize the photon-phonon interactions to demonstrate that photonic Aharonov-Bohm effects do exist for photons. By introducing nonreciprocal phases for photons, we observe experimentally a gauge potential for photons in the visible range based on the photon-phonon interactions in acousto-optic crystals, and demonstrate the photonic Aharonov-Bohm effect. The results presented here point to new possibilities to control and manipulate photons by designing an effective gauge potential. PMID:24476790

Li, Enbang; Eggleton, Benjamin J; Fang, Kejie; Fan, Shanhui

2014-01-01

241

Photonic Aharonov-Bohm effect in photon-phonon interactions  

PubMed Central

The Aharonov–Bohm effect is one of the most intriguing phenomena in both classical and quantum physics, and associates with a number of important and fundamental issues in quantum mechanics. The Aharonov–Bohm effects of charged particles have been experimentally demonstrated and found applications in various fields. Recently, attention has also focused on the Aharonov–Bohm effect for neutral particles, such as photons. Here we propose to utilize the photon–phonon interactions to demonstrate that photonic Aharonov–Bohm effects do exist for photons. By introducing nonreciprocal phases for photons, we observe experimentally a gauge potential for photons in the visible range based on the photon–phonon interactions in acousto-optic crystals, and demonstrate the photonic Aharonov–Bohm effect. The results presented here point to new possibilities to control and manipulate photons by designing an effective gauge potential. PMID:24476790

Li, Enbang; Eggleton, Benjamin J.; Fang, Kejie; Fan, Shanhui

2014-01-01

242

Detecting photon-photon scattering in vacuum at exawatt lasers Daniele Tommasini,1  

E-print Network

Detecting photon-photon scattering in vacuum at exawatt lasers Daniele Tommasini,1 Albert Ferrando for the search of photon-photon scattering in optics experiments. In particular, we show that our previous. On one hand, it has been noted that a fundamental uncertainty in the number of photons is unavoidably

Fernández de Córdoba, Pedro

243

Single-photon generation by pulsed laser in optomechanical system via photon  

E-print Network

Single-photon generation by pulsed laser in optomechanical system via photon blockade effect Liu theoretically analyzed the photon quantum statistics properties of the output field from an optomechanical system driven by different pulsed lasers. Our results show that the probability of generating a single-photon

Wang, Wei Hua

244

PHOTONIC NANOJET PHOTONIC NANOJET  

E-print Network

experiment Novel experiment ShadowgraphShadowgraph Nano-indented slit scanning Nano-indented slit scanning). LASER illumination Photonic nanojet phenomena Optical fiber-based micro-cylinder lens #12;PHOTONICNANOJET SHADOWGRAPH AFM TIP SCANNING NANO-INDENTED SLIT SCANNING SIMULATION EXPERIMENTS 1µm 500nm SEM

Poon, Andrew Wing On

245

Housing and Disability: Data Needs, Statistics and Policy. Proceedings of the National Disability Statistics and Policy Forum (3rd, Washingon, DC, May 13, 1996). Disability Forum Report, Number 3.  

ERIC Educational Resources Information Center

This proceedings reports on a forum which explored housing statistics for people with disabilities. An introduction identifies three broad areas of recommendations for consideration that arose from the forum: (1) a definition (and taxonomy) of housing that meets current and future profiles of where people actually live should be developed: (2)…

LaPlante, Mitchell P., Ed.; Kaye, H. Stephen, Ed.

246

Statistics Indonesia  

NSDL National Science Digital Library

Started in 1997, the Badan Pusat Statistik (BPS-Statistics Indonesia) is a non-departmental Indonesian government institution directly responsible to the Indonesian president. As the law that created this valuable institution stipulates, the BPS is intended to provide data to the government and the public, along cooperating with other international statistical institutions. Visitors looking for statistics on any number of topics will not be disappointed, as the areas covered include agriculture, consumer price indices, employment, energy, foreign trade, mining, population, public finance, tourism, and social welfare. Additionally, there are monthly macro-economic statistical reports for the years from 1998 to 2001 that can be downloaded and viewed as well. The site is rounded out by a collection of some 21 papers from the past four years that analyze various economic data from the country, such as earning data and manufacturing production.

247

Health Manpower Source Book. Manpower Supply and Educational Statistics for Selected Health Occupations: 1968. Public Health Service Publication Number 263, Section 20.  

ERIC Educational Resources Information Center

This publication is a compilation of statistics on supply and education of health manpower in medicine and osteopathy, dentistry, optometry, pharmacy, podiatry, veterinary medicine, nursing, public health, and eight selected allied health occupations. The material is organized by occupations and the following information is presented for each…

National Institutes of Health (DHEW), Bethesda, MD. Bureau of Health Professions Education and Manpower Training.

248

Vital Statistics  

Microsoft Academic Search

This article questions the idea that quantitative methods, in particular the analysis of social statistics, is at odds with critical approaches to geography. It argues that numbers-based research is vital to highlight social injustice and oppression and that quantitative research can meet the requirements of critical geography to be reflexive, politically conscious, and activist. The article highlights two issues of

Mark Ellis

2009-01-01

249

Impact of Geometry on the TM Photonic Band Gaps of Photonic Crystals and Quasicrystals  

NASA Astrophysics Data System (ADS)

Here we demonstrate a novel quantitative procedure to pursue statistical studies on the geometric properties of photonic crystals and photonic quasicrystals (PQCs) which consist of separate dielectric particles. The geometric properties are quantified and correlated to the size of the photonic band gap (PBG) for wide permittivity range using three characteristic parameters: shape anisotropy, size distribution, and feature-feature distribution. Our concept brings statistical analysis to the photonic crystal research and offers the possibility to predict the PBG from a morphological analysis.

Jia, Lin; Bita, Ion; Thomas, Edwin L.

2011-11-01

250

Thermodynamics of a photon gas and deformed dispersion relations  

E-print Network

We resort to the methods of statistical mechanics in order to determine the effects that a deformed dispersion relation has upon the thermodynamics of a photon gas. The ensuing modifications to the density of states, partition function, pressure, internal energy, entropy, and specific heat are calculated. It will be shown that the breakdown of Lorentz invariance can be interpreted as a repulsive interaction, among the photons. Additionally, it will be proved that the presence of a deformed dispersion relation entails an increase in the entropy of the system. In other words, as a consequence of the loss of the aforementioned symmetry the number of microstates available to the corresponding equilibrium state grows.

A. Camacho; A. Macias

2007-02-28

251

Non-classical Properties of Photon-Added Compass State  

NASA Astrophysics Data System (ADS)

We investigate the observable non-classical features of the photon-added compass state (PACS) by its sub-Poissonian statistics, such as the Mandel's parameter, second-order correlation function, photon-number distribution and the quasi-probability distribution functions, peculiarly the negativity in the Wigner distribution of the PACS as the specific non-classical features. We study the squeezing properties of the PACS and find the PACS does not show squeezing properties of the quadrature. Finally, we give the non-Gaussianity of the PACS by the fidelity between the PACS and the squeezed coherent state (SCS).

Ren, Gang; ma, Jian-guo; Du, Jian-ming; Yu, Hai-jun; Zhang, Xiu-Lan

2013-10-01

252

Photon Regeneration Plans  

E-print Network

Precision experiments exploiting low-energy photons may yield information on particle physics complementary to experiments at high-energy colliders, in particular on new very light and very weakly interacting particles, predicted in many extensions of the standard model. Such particles may be produced by laser photons send along a transverse magnetic field. The laser polarization experiment PVLAS may have seen the first indirect signal of such particles by observing an anomalously large rotation of the polarization plane of photons after the passage through a magnetic field. This can be interpreted as evidence for photon disappearance due to particle production. There are a number of experimental proposals to test independently the particle interpretation of PVLAS. Many of them are based on the search for photon reappearance or regeneration, i.e. for ``light shining through a wall''. At DESY, the Axion-Like Particle Search (ALPS) collaboration is currently setting up such an experiment.

A. Ringwald

2006-12-11

253

Possibility of efficient generation of multiphoton entangled states using a one-dimensional nonlinear photonic crystal  

SciTech Connect

A rigorous quantum theory for the generation of multiphoton entangled states based on two consecutive three-frequency interactions of waves in a one-dimensional nonlinear photonic crystal is developed using the field expansion and differentiation methods. The three-photon correlation coefficient and the average photon numbers generated in the structure are calculated. All order expansion terms are included in the calculation. The generation conditions for multiphoton entangled states in such a structure are also analyzed. It is shown that the created photons in the present structures obey the super-Poisson statistics at the interacting frequencies and are in a multiparticle entangled state. This means the nonlinear photonic crystal can be applied as a highly efficient source of an entangled multiphoton for highly integrated all-optical circuits.

Dong Yunxia; Zhang Xiangdong [Department of Physics, Beijing Normal University, Beijing 100875 (China)

2010-03-15

254

Prospects for in vivo estimation of photon linear attenuation coefficients using postprocessing dual-energy CT imaging on a commercial scanner: Comparison of analytic and polyenergetic statistical reconstruction algorithms  

SciTech Connect

Purpose: Accurate patient-specific photon cross-section information is needed to support more accurate model-based dose calculation for low energy photon-emitting modalities in medicine such as brachytherapy and kilovoltage x-ray imaging procedures. A postprocessing dual-energy CT (pDECT) technique for noninvasivein vivo estimation of photon linear attenuation coefficients has been experimentally implemented on a commercial CT scanner and its accuracy assessed in idealized phantom geometries. Methods: Eight test materials of known composition and density were used to compare pDECT-estimated linear attenuation coefficients to NIST reference values over an energy range from 10 keV to 1 MeV. As statistical image reconstruction (SIR) has been shown to reconstruct images with less random and systematic error than conventional filtered backprojection (FBP), the pDECT technique was implemented with both an in-house polyenergetic SIR algorithm, alternating minimization (AM), as well as a conventional FBP reconstruction algorithm. Improvement from increased spectral separation was also investigated by filtering the high-energy beam with an additional 0.5 mm of tin. The law of propagated uncertainty was employed to assess the sensitivity of the pDECT process to errors in reconstructed images. Results: Mean pDECT-estimated linear attenuation coefficients for the eight test materials agreed within 1% of NIST reference values for energies from 1 MeV down to 30 keV, with mean errors rising to between 3% and 6% at 10 keV, indicating that the method is unbiased when measurement and calibration phantom geometries are matched. Reconstruction with FBP and AM algorithms conferred similar mean pDECT accuracy. However, single-voxel pDECT estimates reconstructed on a 1 × 1 × 3 mm{sup 3} grid are shown to be highly sensitive to reconstructed image uncertainty; in some cases pDECT attenuation coefficient estimates exhibited standard deviations on the order of 20% around the mean. Reconstruction with the statistical AM algorithm led to standard deviations roughly 40% to 60% less than FBP reconstruction. Additional tin filtration of the high energy beam exhibits similar pDECT estimation accuracy as the unfiltered beam, even when scanning with only 25% of the dose. Using the law of propagated uncertainty, low Z materials are found to be more sensitive to image reconstruction errors than high Z materials. Furthermore, it is estimated that reconstructed CT image uncertainty must be limited to less than 0.25% to achieve a target linear-attenuation coefficient estimation uncertainty of 3% at 28 keV. Conclusions: That pDECT supports mean linear attenuation coefficient measurement accuracies of 1% of reference values for energies greater than 30 keV is encouraging. However, the sensitivity of the pDECT measurements to noise and systematic errors in reconstructed CT images warrants further investigation in more complex phantom geometries. The investigated statistical reconstruction algorithm, AM, reduced random measurement uncertainty relative to FBP owing to improved noise performance. These early results also support efforts to increase DE spectral separation, which can further reduce the pDECT sensitivity to measurement uncertainty.

Evans, Joshua D., E-mail: jevans2@mcvh-vcu.edu; Yu, Yaduo; Williamson, Jeffrey F. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)] [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Whiting, Bruce R. [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States)] [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States); O’Sullivan, Joseph A. [Department of Electrical and Systems Engineering, Washington University, St. Louis, Missouri 63130 (United States)] [Department of Electrical and Systems Engineering, Washington University, St. Louis, Missouri 63130 (United States); Politte, David G. [Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri 63110 (United States)] [Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri 63110 (United States); Klahr, Paul H. [Philips Healthcare, 595 Miner Rd., Highland Hts., Ohio 44143 (United States)] [Philips Healthcare, 595 Miner Rd., Highland Hts., Ohio 44143 (United States)

2013-12-15

255

Sub-Poissonian statistics of Rydberg-interacting dark-state polaritons  

E-print Network

Interfacing light and matter at the quantum level is at the heart of modern atomic and optical physics and enables new quantum technologies involving the manipulation of single photons and atoms. A prototypical atom-light interface is electromagnetically induced transparency, in which quantum interference gives rise to hybrid states of photons and atoms called dark-state polaritons. We have observed individual dark-state polaritons as they propagate through an ultracold atomic gas involving Rydberg states. Strong long-range interactions between Rydberg atoms give rise to an effective interaction blockade for dark-state polaritons, which results in large optical nonlinearities and modified polariton number statistics. The observed statistical fluctuations drop well below the quantum noise limit indicating that photon correlations modified by the strong interactions have a significant back-action on the Rydberg atom statistics.

Christoph S. Hofmann; Georg Günter; Hanna Schempp; Martin Robert-de-Saint-Vincent; Martin Gärttner; Jörg Evers; Shannon Whitlock; Matthias Weidemüller

2012-11-30

256

The photon gas formulation of thermal radiation  

NASA Technical Reports Server (NTRS)

A statistical consideration of the energy, the linear momentum, and the angular momentum of the photons that make up a thermal radiation field was presented. A general nonequilibrium statistical thermodynamics approach toward a macroscopic description of thermal radiation transport was developed and then applied to the restricted equilibrium statistical thermostatics derivation of the energy, linear momentum, and intrinsic angular momentum equations for an isotropic photon gas. A brief treatment of a nonisotropic photon gas, as an example of the results produced by the nonequilibrium statistical thermodynamics approach, was given. The relativistic variation of temperature and the invariance of entropy were illustrated.

Ried, R. C., Jr.

1975-01-01

257

Photon absorptiometry  

SciTech Connect

Recently, there has been a renewed interest in the detection and treatment of osteoporosis. This paper is a review of the merits and limitations of the various noninvasive modalities currently available for the measurement of bone mineral density with special emphasis placed upon the nuclear medicine techniques of single-photon and dual-photon absorptiometry. The clinicians should come away with an understanding of the relative advantages and disadvantages of photon absorptiometry and its optimal clinical application. 49 references.

Velchik, M.G.

1987-01-01

258

Photonic Hypercrystals  

NASA Astrophysics Data System (ADS)

We introduce a new "universality class" of artificial optical media—photonic hypercrystals. These hyperbolic metamaterials, with periodic spatial variation of dielectric permittivity on subwavelength scale, combine the features of optical metamaterials and photonic crystals. In particular, surface waves supported by a hypercrystal possess the properties of both the optical Tamm states in photonic crystals and surface-plasmon polaritons at the metal-dielectric interface.

Narimanov, Evgenii E.

2014-10-01

259

Spectral resolution in pixel detectors with single photon processing  

NASA Astrophysics Data System (ADS)

Pixel detectors based on photon counting or single photon processing readout are becoming popular for spectral X-ray imaging. The detector is based on deep submicron electronics with functions to determine the energy of each individual photon in every pixel. The system is virtually noiseless when it comes to the number of the detected photons. However noise and variations in system parameters affect the determination of the photon energy. Several factors affect the energy resolution in the system. In the readout electronics the most important factors are the threshold dispersion, the gain variation and the electronic noise. In the sensor contributions come from charge sharing, variations in the charge collection efficiency, leakage current and the statistical nature of the charge generation, as described by the Fano factor. The MEDIPIX technology offers a powerful tool for investigating these effects since energy spectra can be captured in each pixel. In addition the TIMEPIX chip, when operated in Time over Threshold mode, offers an opportunity to analyze individual photon interactions, thus addressing charge sharing and fluorescence. Effects of charge sharing and the properties of charge summing can be investigated using MEDIPIX3RX. Experiments are performed using both Si and CdTe detectors. In this paper we discuss the various contributions to the spectral noise and how they affect detector response. The statements are supported with experimental data from MEDIPIX-type detectors.

Fröjdh, C.; Krapohl, D.; Reza, S.; Fröjdh, E.; Thungström, G.; Norlin, B.

2013-09-01

260

Quantum Storage of a Photonic Polarization Qubit in a Solid  

NASA Astrophysics Data System (ADS)

We report on the quantum storage and retrieval of photonic polarization quantum bits onto and out of a solid state storage device. The qubits are implemented with weak coherent states at the single photon level, and are stored for a predetermined time of 500 ns in a praseodymium doped crystal with a storage and retrieval efficiency of 10%, using the atomic frequency comb scheme. We characterize the storage by using quantum state tomography, and find that the average conditional fidelity of the retrieved qubits exceeds 95% for a mean photon number ?=0.4. This is significantly higher than a classical benchmark, taking into account the Poissonian statistics and finite memory efficiency, which proves that our crystal functions as a quantum storage device for polarization qubits. These results extend the storage capabilities of solid state quantum light matter interfaces to polarization encoding, which is widely used in quantum information science.

Gündo?an, Mustafa; Ledingham, Patrick M.; Almasi, Attaallah; Cristiani, Matteo; de Riedmatten, Hugues

2012-05-01

261

Three-photon entanglement in structured ?(2) media  

NASA Astrophysics Data System (ADS)

We investigate production of three-photon states in cascaded parametric down-conversion (PDC). The analysis includes preparation of Greenberger-Horne-Zeilinger polarization-entangled states in cascaded type-II and type-I PDC in the framework of considering the dual-grid structure that involves two periodically poled crystals. Considering cascaded optical parametric oscillator (OPO) driven by a sequence of laser pulses with Gaussian time-dependent envelopes, we investigate quantum statistical properties of high intensity mode generated in intracavity three-photon splitting. Calculating the normalized third-order correlation function below-and at the generation threshold, we demonstrate that in the pulsed regime, depending on the duration of pulses and the time-interval separations between them, the degree of three-photon-number correlation essentially exceed the analogous one for the case of continuous pumping.

Gevorgyan, T. V.; Kryuchkyan, G. Yu.

2011-07-01

262

The photon  

NASA Astrophysics Data System (ADS)

There are no TEM waves, only photons. Lets build a photon, using a radio antenna. A short antenna (2L<< ?) simplifies the calculation, letting B fall off everywhere as 1/r^2. The Biot-Savart law finds B = (?0/4?)(LI0/r^2)??t. The magnetic flux thru a semi-circle of radius ?/2 is set equal to the flux quantum h/e, determining the needed source strength, LI0. From this, one can integrate the magnetic energy density over a sphere of radius ?/2 and finds it to be 1.0121 hc/?. Pretty close. A B field collapses when the current ceases, but the photon evades this by creating a ?0E / t displacement current at center that fully supports the toroidal B assembly as it moves at c. This E=vxB arises because the photon moves at c. Stopped, a photon decays. At every point along the photon's path, an observer will note a transient oscillation of an E field. This sources the EM ``guiding wave'', carrying little or no energy and expanding at c. At the head of the photon, all these spherical guiding waves gather ``in-phase'' as a planar wavefront. This model speaks to all the many things we know about light. The photon is tiny, but its guiding wave is huge.

Collins, Russell L.

2009-10-01

263

Folding Photons  

SciTech Connect

Scientists have shown that wrinkles and folds can be used to maximize the absorption of low-energy photons by efficiently redirecting them into a thin absorbing film. This inexpensive technique for structuring photonic substrates could be used to increase the efficiency of many organic photovoltaic cells.

Gregg, B. A.; van de Lagemaat, J.

2012-05-01

264

Common statistical tests  

Microsoft Academic Search

A recent survey by BeGole of four major orthodontic journals revealed that76% of the original and scientific articles published in 1997 incorporated statistical procedures in their methodologies. To evaluate the information presented in these scientific articles, the clinician needs to have an understanding of the statistical techniques used in them. Although a number of the statistical methodologies were complex, requiring

Rose D. Sheats; V. Shane Pankratz

2002-01-01

265

Introduction Statistical  

E-print Network

Advanced Natural Language Processing Introduction Statistical NLP MIA - Master on Artificial Statistical NLP 1 Introduction Course goals Practical information 2 Statistical NLP #12;Advanced Natural Language Processing Introduction Course goals Statistical NLP 1 Introduction Course goals Practical

Ageno, Alicia

266

PHOTON2  

NSDL National Science Digital Library

Funded through a three-year grant from the Advanced Technological Education (ATE) program of the National Science Foundation (NSF), Project PHOTON2 builds on the highly successful "Alliance" model developed through the previous Project PHOTON.In both projects, educators from several geographic locations (four to six regions nationally) are brought together to facilitate photonics technology education at their institutions that is intelligently developed and seamlessly articulated. The âÂÂAlliancesâ consist of four to six participants per region, including high school and two- and four-year college science, technology, engineering, and math instructors, as well as their institution's career and admissions counselors. On this site, visitors will find curriculum materials, information about the PHOTON2 laboratory kit and careers in photonics, links to external tutorials and applets, and societies and organizations. Visitors can also find out more about the project, its team, newsletter, conference papers, workshop, and a distance learning course for educators.

2010-10-07

267

Photon Position Operator and Localization of Photons inside a Waveguide  

E-print Network

In this article, we show that in the level of quantum mechanics, a photon position operator with commuting components can be obtained in a more natural way; in the level of quantum field theory, the photon position operator corresponds to the center of the photon number. It is most interesting for us to show that, a photon inside a waveguide can be localized in the same sense that a massive particle can be localized in free space, and just as that it is impossible to localize a massive particle with a greater precision than its Compton wavelength, one can also arrival at a similar conclusion: it is impossible to localize a photon inside a waveguide with a greater precision than its equivalent Compton wavelength, which owing to evanescent-wave or photon-tunneling phenomena.

Zhi-Yong Wang; Cai-Dong Xiong; Ole Keller

2005-11-30

268

Breakdown of Bose-Einstein distribution in photonic crystals  

E-print Network

In the last two decades, considerable advances have been made in the investigation of nano-photonics in photonic crystals. Previous theoretical investigations of photon dynamics were carried out at zero temperature. Here, we investigate micro/nano cavity photonics in photonic crystals at finite temperature. Due to photonic-band-gap-induced non-Markovian dynamics, we discover that cavity photons in photonic crystals do not obey the standard Bose-Einstein statistical distribution. Within the photonic band gap and in the vicinity of the band edge, cavity photons combine nontrivial quantum dissipation with thermal fluctuations to form photon states that can memorize the initial cavity state information. As a result, Bose-Einstein distribution is completely broken down in these regimes, even if the thermal energy is larger than the photonic band gap.

Ping-Yuan Lo; Heng-Na Xiong; Wei-Min Zhang

2013-11-21

269

VOLUME 80, NUMBER 9 P H Y S I C A L R E V I E W L E T T E R S 2 MARCH 1998 Experimental Limits on the Photon Mass and Cosmic Magnetic Vector Potential  

E-print Network

- gested by Georgi, Ginsparg, and Glashow [10] to affect cosmic background radiation. Photon mass, a very. Possible anisotropy of the speed of light with respect to the cosmic background radiation [11] may on the Photon Mass and Cosmic Magnetic Vector Potential Roderic Lakes Department of Engineering Physics

Lakes, Roderic

270

Strong photon antibunching of symmetric and antisymmetric modes in weakly nonlinear photonic molecules  

NASA Astrophysics Data System (ADS)

We study the photon statistics of symmetric and antisymmetric modes in a photonic molecule consisting of two linearly coupled nonlinear cavity modes. Our calculations show that strong photon antibunching of both symmetric and antisymmetric modes can be obtained even when the nonlinearity in the photonic molecule is weak. The strong antibunching effect results from the destructive interference between different paths for two-photon excitation. Moreover, we find that the optimal frequency detunings for strong photon antibunching in the symmetric and antisymmetric modes are linearly dependent on the coupling strength between the cavity modes in the photonic molecule. This implies that the photonic molecules can be used to generate tunable single-photon sources by tuning the values of the coupling strength between the cavity modes with weak nonlinearity.

Xu, Xun-Wei; Li, Yong

2014-09-01

271

Photon diffraction  

NASA Astrophysics Data System (ADS)

In current light models, a particle-like model of light is inconsistent with diffraction observations. A model of light is proposed wherein photon inferences are combined with the cosmological scalar potential model (SPM). That the photon is a surface with zero surface area in the travel direction is inferred from the Michelson-Morley experiment. That the photons in slits are mathematically treated as a linear antenna array (LAA) is inferred from the comparison of the transmission grating interference pattern and the single slit diffraction pattern. That photons induce a LAA wave into the plenum is inferred from the fractal model. Similarly, the component of the photon (the hod) is treated as a single antenna radiating a potential wave into the plenum. That photons are guided by action on the surface of the hod is inferred from the SPM. The plenum potential waves are a real field (not complex) that forms valleys, consistent with the pilot waves of the Bohm interpretation of quantum mechanics. Therefore, the Afshar experiment result is explained, supports Bohm, and falsifies Copenhagen. The papers may be viewed at http://web.citcom.net/˜scjh/.

Hodge, John

2009-11-01

272

Generation of photon-added coherent states via photon-subtracted generalised coherent states  

NASA Astrophysics Data System (ADS)

Based on previous work [A. Dehghani, B. Mojaveri, J. Phys. A 45, 095304 (2012)], we introduce photon-subtracted generalised coherent states (PSGCSs) |z,m?r: = am|z?r, where m is a nonnegative integer and |z?r denote the generalised coherent states (GCSs). We have shown that the states |z,m?r are eigenstates of a non-Hermitian operator f(n?,m)â, where f(n?,m) is a nonlinear function of the number operator N? . Also, the states | z, - m ? r can be considered as another set of eigenstates for negative values of m. They span the truncated Fock space without the first m lowest-lying basis states: | 0 ? , | 1 ? , | 2 ? ,...,| m - 1 ? which are reminiscent of the so-called photon-added coherent states. The resolution of the identity property, which is the most important property of coherent states, is realised for |z,m?r as well as for |z, - m?r. Some nonclassical features such as sub-Poissonian statistics and quadrature squeezing of the states |z, ± m?r are compared. We show that the annihilation operator diminishes the mean number of photons of the initial state |z?r. Finally we show that |z,m?r can be produced through a simple theoretical scheme.

Mojaveri, Bashir; Dehghani, Alireza

2014-10-01

273

32. Statistics 1 32. STATISTICS  

E-print Network

32. Statistics 1 32. STATISTICS Revised September 2007 by G. Cowan (RHUL). This chapter gives an overview of statistical methods used in High Energy Physics. In statistics, we are interested in using's validity or to determine the values of its parameters. There are two main approaches to statistical

Masci, Frank

274

Reform by the Numbers.  

ERIC Educational Resources Information Center

Although numbers such as average test scores or dropout rates can capture part of a school system's success or failure, school statistics seldom tell the whole story. School board members should realize that numbers might measure compliance or process, rather than improvement. Also, improvements in numbers might reflect changes in assessment…

Hanford, Terry; White, Kathleen

1991-01-01

275

Single photon interference Single photon interference  

E-print Network

Single photon interference Single photon interference with a Fresnel biprism Contacts: Jean-François Roch François Treussart Philippe Grangier Introduction Single photon source Interference fringes Anticorrelation Archives Single-photon interference Single photons emitted by the N-V colour centre are sent

Spagnolo, Filippo

276

Lighting affects appearance LightSource emits photons  

E-print Network

1 Lighting affects appearance #12;2 LightSource emits photons Photons travel in a straight line surfaces. Basic fact: Light is linear Double intensity of sources, double photons reaching eye. Turn on two lights, and photons reaching eye are same as sum of number when each light is on separately. This means

Jacobs, David

277

Natural photonic crystals  

NASA Astrophysics Data System (ADS)

Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

Vigneron, Jean Pol; Simonis, Priscilla

2012-10-01

278

MCNP: Photon benchmark problems  

SciTech Connect

The recent widespread, markedly increased use of radiation transport codes has produced greater user and institutional demand for assurance that such codes give correct results. Responding to these pressing requirements for code validation, the general purpose Monte Carlo transport code MCNP has been tested on six different photon problem families. MCNP was used to simulate these six sets numerically. Results for each were compared to the set's analytical or experimental data. MCNP successfully predicted the analytical or experimental results of all six families within the statistical uncertainty inherent in the Monte Carlo method. From this we conclude that MCNP can accurately model a broad spectrum of photon transport problems. 8 refs., 30 figs., 5 tabs.

Whalen, D.J.; Hollowell, D.E.; Hendricks, J.S.

1991-09-01

279

Topological Photonics  

E-print Network

Topology is revolutionizing photonics, bringing with it new theoretical discoveries and a wealth of potential applications. This field was inspired by the discovery of topological insulators, in which interfacial electrons transport without dissipation even in the presence of impurities. Similarly, new optical mirrors of di?fferent wave-vector space topologies have been constructed to support new states of light propagating at their interfaces. These novel waveguides allow light to flow around large imperfections without back-reflection. The present review explains the underlying principles and highlights the major findings in photonic crystals, coupled resonators, metamaterials and quasicrystals.

Lu, Ling; Solja?i?, Marin

2014-01-01

280

Topological photonics  

NASA Astrophysics Data System (ADS)

The application of topology, the mathematics of conserved properties under continuous deformations, is creating a range of new opportunities throughout photonics. This field was inspired by the discovery of topological insulators, in which interfacial electrons transport without dissipation, even in the presence of impurities. Similarly, the use of carefully designed wavevector-space topologies allows the creation of interfaces that support new states of light with useful and interesting properties. In particular, this suggests unidirectional waveguides that allow light to flow around large imperfections without back-reflection. This Review explains the underlying principles and highlights how topological effects can be realized in photonic crystals, coupled resonators, metamaterials and quasicrystals.

Lu, Ling; Joannopoulos, John D.; Solja?i?, Marin

2014-11-01

281

NON-Shor Factorization Via BEQS BEC: Watkins Number-Theory "Pure"-Mathematics U With Statistical-Physics; Benford Log-Law Inversion to ONLY BEQS digit d=0 BEC!!!  

NASA Astrophysics Data System (ADS)

Weiss-Page-Holthaus[Physica A,341,586(04); http://arxiv.org/abs/cond-mat/0403295] number-FACTORIZATION VIA BEQS BEC VS.(?) Shor-algorithm, strongly-supporting Watkins' [www.secamlocal.ex.ac.uk/people/staff/mrwatkin/] Intersection of number-theory "pure"-maths WITH (Statistical)-Physics, as Siegel[AMS Joint.Mtg.(02)-Abs.973-60-124] Benford logarithmic-law algebraic-INVERSION to ONLY BEQS with d=0 digit =oo gapFUL BEC!!! Siegel Riemann-hypothesis proof via Rayleigh[Phil.Trans.CLXI(1870)]-Polya[Math.Ann.(21)]-[Random-Walks & Electric-Nets., MAA(81)]-"Anderson"[PRL(58)]-localization-Siegel[Symp.Fractals,MRS Fall Mtg.(89)-5-papers!!!] FUZZYICS=CATEGORYICS: [LOCALITY]--MORPHISM/CROSSOVER/ AUTMATHCAT/DIM-CAT/ ANTONYM-->(GLOBALITY) FUNCTOR/SYNONYM/ concomitance to "noise"<=/Fluct.-Dissip. theorem/ FUNCTOR/SYNONYM/ equivalence/proportionality to => "generalized-susceptibility" power-spectrum [FLAT/FUNCTIONLESS/WHITE]--MORPHISM/ CROSSOVER/AUTMATHCAT/DIM-CAT/ANTONYM--> HYPERBOLICITY/ZIPF-law INEVITABILITY) intersection with ONLY BEQS BEC).

Lyons, M.; Carl-Ludwig Siegel, Edward

2011-03-01

282

Single-Photon-Sensitive HgCdTe Avalanche Photodiode Detector  

NASA Technical Reports Server (NTRS)

The purpose of this program was to develop single-photon-sensitive short-wavelength infrared (SWIR) and mid-wavelength infrared (MWIR) avalanche photodiode (APD) receivers based on linear-mode HgCdTe APDs, for application by NASA in light detection and ranging (lidar) sensors. Linear-mode photon-counting APDs are desired for lidar because they have a shorter pixel dead time than Geiger APDs, and can detect sequential pulse returns from multiple objects that are closely spaced in range. Linear-mode APDs can also measure photon number, which Geiger APDs cannot, adding an extra dimension to lidar scene data for multi-photon returns. High-gain APDs with low multiplication noise are required for efficient linear-mode detection of single photons because of APD gain statistics -- a low-excess-noise APD will generate detectible current pulses from single photon input at a much higher rate of occurrence than will a noisy APD operated at the same average gain. MWIR and LWIR electron-avalanche HgCdTe APDs have been shown to operate in linear mode at high average avalanche gain (M > 1000) without excess multiplication noise (F = 1), and are therefore very good candidates for linear-mode photon counting. However, detectors fashioned from these narrow-bandgap alloys require aggressive cooling to control thermal dark current. Wider-bandgap SWIR HgCdTe APDs were investigated in this program as a strategy to reduce detector cooling requirements.

Huntington, Andrew

2013-01-01

283

PHOTON SCIENCES DIRECTORATE ADVANCED PHOTON SOURCE  

E-print Network

PHOTON SCIENCES DIRECTORATE ADVANCED PHOTON SOURCE G. B. STEPHENSON ASSOCIATE LABORATORY DIRECTOR DIRECTOR, ADVANCED PHOTON SOURCE (VACANT) D. M. MILLS G. SRAJER Deputy Assoc. Lab. Dir. Deputy Assoc. Lab

Kemner, Ken

284

Statistical Summaries: Public Institutions.  

ERIC Educational Resources Information Center

This document, presents a statistical portrait of the Virginia's 17 public higher education institutions. Data provided include: enrollment figures (broken down in categories such as sex, residency, full- and part-time status, residence, ethnicity, age, and level of postsecondary education); FTE figures; admissions statistics (such as number

Virginia State Council of Higher Education, Richmond.

285

Photon doses in NPL standard neutron fields.  

PubMed

Standard neutron fields are invariably accompanied by a photon component due to the neutron-generating reactions and secondary neutron interactions in the surrounding environment. A set of energy-compensated Geiger-Müller (GM) tubes and electronic personal dosemeters (EPDs) have been used to measure the photon dose rates in a number of standard radionuclide and accelerator-based neutron fields. The GM tubes were first characterised in standard radioisotope and X-ray photon fields and then modelled using MCNP to determine their photon dose response as a function of energy. Values for the photon-to-neutron dose equivalent ratios are presented and compared with other published values. PMID:24126485

Roberts, N J; Horwood, N A; McKay, C J

2014-10-01

286

Engineered quantum dot single-photon sources  

NASA Astrophysics Data System (ADS)

Fast, high efficiency and low error single-photon sources are required for the implementation of a number of quantum information processing applications. The fastest triggered single-photon sources to date have been demonstrated using epitaxially grown semiconductor quantum dots (QDs), which can be conveniently integrated with optical microcavities. Recent advances in QD technology, including demonstrations of high temperature and telecommunications wavelength single-photon emission, have made QD single-photon sources more practical. Here we discuss the applications of single-photon sources and their various requirements, before reviewing the progress made on a QD platform in meeting these requirements.

Buckley, Sonia; Rivoire, Kelley; Vu?kovi?, Jelena

2012-12-01

287

VOLUME 80, NUMBER 2 P H Y S I C A L R E V I E W L E T T E R S 12 JANUARY 1998 Human Balance out of Equilibrium: Nonequilibrium Statistical Mechanics in Posture Control  

E-print Network

of Equilibrium: Nonequilibrium Statistical Mechanics in Posture Control Michael Lauk,1,2,4 Carson C. Chow,1 Nonequilibrium statistical mechanics [1­4] provides a theoretical framework for studying stochastic systems

Collins, James J.

288

Post-Processing Free Spatio-Temporal Optical Random Number Generator Resilient to Hardware Failure and Signal Injection Attacks  

E-print Network

We present a random number generator based on quantum effects in photonic emission and detection. It is unique in simultaneous use of both spatial and temporal quantum information contained in the system which makes it resilient to hardware failure and signal injection attacks. We show that its deviation from randomness cam be estimated based on simple measurements. Generated numbers pass NIST Statistical test suite without post-processing.

Mario Stip?evi?; John Bowers

2014-10-02

289

Observing photonic de Broglie waves without the NOON state  

E-print Network

The photonic de Broglie wave, in which an ensemble of $N$ identical photons with wavelength $\\lambda$ reveals $\\lambda/N$ interference fringes, has been known to be a unique feature exhibited by the photon number-path entangled state or the NOON state. Here, we report the observation of the photonic de Broglie wave for a pair of photons, generated by spontaneous parametric down-conversion, that are not photon number-path entangled. We also show that the photonic de Broglie wave can even be observed for a pair of photons that are completely separable (i.e., no entanglement in all degrees of freedom) and distinguishable. The experimental and theoretical results suggest that the photonic de Broglie wave is, in fact, not related to the entanglement of the photons, rather it is related to the indistinguishable pathways established by the measurement scheme.

Osung Kwon; Young-Sik Ra; Yoon-Ho Kim

2009-10-30

290

Descriptive statistics.  

PubMed

In this article, we introduced basic concepts of statistics, type of distributions, and descriptive statistics. A few examples were also provided. The basic concepts presented herein are only a fraction of the concepts related to descriptive statistics. Also, there are many commonly used distributions not presented herein, such as Poisson distributions for rare events and exponential distributions, F distributions, and logistic distributions. More information can be found in many statistics books and publications. PMID:19891281

Shi, Runhua; McLarty, Jerry W

2009-10-01

291

Photon collider at TESLA  

E-print Network

High energy photon colliders (gamma-gamma, gamma-electron) based on backward Compton scattering of laser light is a very natural addition to e+e- linear colliders. In this report we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case the gamma-gamma luminosity luminosity in the high energy part of spectrum can reach (1/3)L_{e+e-}. Typical cross sections of interesting processes in gamma-gamma collisions are higher than those in e+e- collisions by about one order of magnitude, so the number of events in gamma-gamma collisions will be more than that in e+e- collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is ``an optical storage ring (optical trap)'' with diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based at TESLA, its possible parameters and existing problems.

Valery Telnov

2000-10-13

292

Statistical Diversions  

ERIC Educational Resources Information Center

The term "data snooping" refers to the practice of choosing which statistical analyses to apply to a set of data after having first looked at those data. Data snooping contradicts a fundamental precept of applied statistics, that the scheme of analysis is to be planned in advance. In this column, the authors shall elucidate the statistical

Petocz, Peter; Sowey, Eric

2012-01-01

293

Quantum theory of a two-photon micromaser  

SciTech Connect

We present the quantum theory of a microscopic maser operating on a degenerate two-photon transition between levels of the same parity. We derive both a master equation and a Fokker-Planck equation for this system, and show that quantum effects may have a substantial influence on the behavior of the maser. They modify the oscillation threshold and make external triggering of this maser unnecessary, whereas, according to semiclassical theory, such a triggering is required to start up the maser oscillation. We derive the phase-diffusion properties of the field and show that the diffusion coefficient is complex in this case, its imaginary part being associated with a frequency shift of the field inside the cavity. We show that, in steady state, the photon-number statistics is sub-Poissonian for a wide range of pumping rates.

Davidovich, L.; Raimond, J.M.; Brune, M.; Haroche, S.

1987-10-15

294

Vesicle Photonics  

NASA Astrophysics Data System (ADS)

Amphiphiles, under appropriate conditions, can self-assemble into nanoscale thin membrane vessels (vesicles) that encapsulate and hence protect and transport molecular payloads. Vesicles assemble naturally within cells but can also be artificially synthesized. In this article, we review the mechanisms and applications of light-field interactions with vesicles. By being associated with light-emitting entities (e.g., dyes, fluorescent proteins, or quantum dots), vesicles can act as imaging agents in addition to cargo carriers. Vesicles can also be optically probed on the basis of their nonlinear response, typically from the vesicle membrane. Light fields can be employed to transport vesicles by using optical tweezers (photon momentum) or can directly perturb the stability of vesicles and hence trigger the delivery of the encapsulated payload (photon energy). We conclude with emerging vesicle applications in biology and photochemical microreactors.

Vasdekis, A. E.; Scott, E. A.; Roke, S.; Hubbell, J. A.; Psaltis, D.

2013-07-01

295

December 2000 A STATISTICAL TEST  

E-print Network

December 2000 A STATISTICAL TEST SUITE FOR RANDOM AND PSEUDORANDOM NUMBER GENERATORS challenges in authentication protocols. NIST Special Publication (SP) 800-22, A Statistical Test Suite testing of random number and pseudorandom number generators (RNGs and PRNGs) that may be used for many

296

Pulsed "three-photon" light  

E-print Network

Generating multi-photon entangled states is a primary task for applications of quantum information processing. We investigate production of photon-triplet in a regime of light amplification in second-order nonlinear media under action of a pulsed laser beam. For this goal the process of cascaded three-photon splitting in an optical cavity driven by a sequence of laser pulses with Gaussian time-dependent envelopes is investigated. Considering production of photon-triplet for short-time regime and in the cascaded three-wave collinear configuration Generating multi-photon entangled states is a primary task for applications of quantum information processing. We investigate production of photon-triplet in a regime of light amplification in second-order nonlinear media under action of a pulsed laser beam. For this goal the process of cascaded three-photon splitting in an optical cavity driven by a sequence of laser pulses with Gaussian time-dependent envelopes is investigated. Considering production of photon-triplet for short-time regime and in the cascaded three-wave collinear configuration we shortly analyze preparation of polarization-non-product states looking further applications of these results in the cascaded optical parametric oscillator. It is also demonststed the nonclassical characteritics of the photon-triplet in phase-space on the base of the Wigner function. Calculating the normalized third-order correlation functions below-and at the generation threshold of cascaded optical parametric oscillator, we demonstrate that in the pulsed regime, depending on the duration of pulses and the time-interval separations between them, the degree of three-photon-number correlation essentially exceed the analogous one for the case of continuous pumping.

T. V. Gevorgyan; G. Yu. Kryuchkyan

2012-05-17

297

Photon detectors  

SciTech Connect

J. Seguinot and T. Ypsilantis have recently described the theory and history of Ring Imaging Cherenkov (RICH) detectors. In this paper, I will expand on these excellent review papers, by covering the various photon detector designs in greater detail, and by including discussion of mistakes made, and detector problems encountered, along the way. Photon detectors are among the most difficult devices used in physics experiments, because they must achieve high efficiency for photon transport and for the detection of single photo-electrons. For gaseous devices, this requires the correct choice of gas gain in order to prevent breakdown and wire aging, together with the use of low noise electronics having the maximum possible amplification. In addition, the detector must be constructed of materials which resist corrosion due to photosensitive materials such as, the detector enclosure must be tightly sealed in order to prevent oxygen leaks, etc. The most critical step is the selection of the photocathode material. Typically, a choice must be made between a solid (CsI) or gaseous photocathode (TMAE, TEA). A conservative approach favors a gaseous photocathode, since it is continuously being replaced by flushing, and permits the photon detectors to be easily serviced (the air sensitive photocathode can be removed at any time). In addition, it can be argued that we now know how to handle TMAE, which, as is generally accepted, is the best photocathode material available as far as quantum efficiency is concerned. However, it is a very fragile molecule, and therefore its use may result in relatively fast wire aging. A possible alternative is TEA, which, in the early days, was rejected because it requires expensive CaF{sub 2} windows, which could be contaminated easily in the region of 8.3 eV and thus lose their UV transmission.

Va`vra, J.

1995-10-01

298

Number Track  

NSDL National Science Digital Library

Students can use this interactive Flash applet to practice ordering whole numbers within 20. The applet displays a track and number tiles, which the user drags to create the correct sequence of numbers 1 through 20. Users may choose from four levels: place 5 missing numbers, place 10 numbers, arrange all 20 numbers, or create your own challenge.

Bunker, Dan

2010-01-01

299

Black-body photon clustering by semi-classical means  

E-print Network

If stimulated emission could be turned off then only uncorrelated photons would be emitted from black bodies and the photon counting statistics would be Poissonian. Through the process of stimulated emission, some fraction of the photons emitted from a black body are correlated and thus emitted in clusters. This photon clustering can be calculated by semi-classical means. The corresponding results are in agreement with quantum theory.

J. P. Lestone

2008-04-09

300

A scheme for amplification and discrimination of photons  

E-print Network

A scheme for exploring photon number amplification and discrimination is presented based on the interaction of a large number of two-level atoms with a single mode radiation field. The fact that the total number of photons and atoms in the excited states is a constant under time evolution in Dicke model is exploited to rearrange the atom-photon numbers. Three significant predictions emerge from our study: Threshold time for initial exposure to photons, time of perception (time of maximum detection probability), and discrimination of first few photon states.

A. R. Usha Devi; R. Prabhu; A. K. Rajagopal

2008-02-16

301

Optical Quantum Random Number Generator  

Microsoft Academic Search

A physical random number generator based on the intrinsic randomness of\\u000aquantum mechanics is described. The random events are realized by the choice of\\u000asingle photons between the two outputs of a beamsplitter. We present a simple\\u000adevice, which minimizes the impact of the photon counters' noise, dead-time and\\u000aafter pulses.

Nicolas Gisin; Olivier Guinnard; Laurent Guinnard; Hugo Zbinden

1999-01-01

302

Di-Photon and Photon+b/c Production Cross Sections at Ecm=1.96 TeV  

E-print Network

Measurements of the di-photon cross section have been made in the central region and are found to be in good agreement with NLO QCD predictions. The cross section of events containing a photon and additional heavy flavour jet have also been measured, as well as the ratio of photon+b to photon+c. The statistically limited sample shows good agreement with Leading Order predictions. 1

Anant Gajjar; Cdf Collaboration

2005-01-01

303

Di-Photon and Photon+b/c Production Cross Sections at Ecm=1.96 TeV  

E-print Network

Measurements of the di-photon cross section have been made in the central region and are found to be in good agreement with NLO QCD predictions. The cross section of events containing a photon and additional heavy flavour jet have also been measured, as well as the ratio of photon+b to photon+c. The statistically limited sample shows good agreement with Leading Order predictions.

A. Gajjar; for the CDF Collaboration

2005-05-16

304

Di-photon and Photon+b/c Production Cross Sections at Ecm=2TeV  

E-print Network

The inclusive di-photon cross-section is measured in the central region and found to be in good agreement with NLO QCD predictions. Cross-sections are presented for events containing an energetic photon in addition to a heavy flavour jet. The ratio of photon+c to photon+b events is also measured. Results are currently statistically limited and in agreement with Pythia predictions.

Ronan McNulty

2004-06-24

305

Di-photon and photon + b/c production cross sections at Ecm = 1.96- TeV  

SciTech Connect

Measurements of the di-photon cross section have been made in the central region and are found to be in good agreement with NLO QCD predictions. The cross section of events containing a photon and additional heavy flavor jet have also been measured, as well as the ratio of photon + b to photon + c. The statistically limited sample shows good agreement with Leading Order predictions.

Gajjar, Anant; /Liverpool U.

2005-05-01

306

Multi-element superconducting nanowire single photon detectors  

E-print Network

Single-photon-detector arrays can provide unparalleled performance and detailed information in applications that require precise timing and single photon sensitivity. Such arrays have been demonstrated using a number of ...

Dauler, Eric A. (Eric Anthony), 1980-

2009-01-01

307

Integrated spatial multiplexing of heralded single-photon sources  

PubMed Central

The non-deterministic nature of photon sources is a key limitation for single-photon quantum processors. Spatial multiplexing overcomes this by enhancing the heralded single-photon yield without enhancing the output noise. Here the intrinsic statistical limit of an individual source is surpassed by spatially multiplexing two monolithic silicon-based correlated photon pair sources in the telecommunications band, demonstrating a 62.4% increase in the heralded single-photon output without an increase in unwanted multipair generation. We further demonstrate the scalability of this scheme by multiplexing photons generated in two waveguides pumped via an integrated coupler with a 63.1% increase in the heralded photon rate. This demonstration paves the way for a scalable architecture for multiplexing many photon sources in a compact integrated platform and achieving efficient two-photon interference, required at the core of optical quantum computing and quantum communication protocols. PMID:24107840

Collins, M.J.; Xiong, C.; Rey, I.H.; Vo, T.D.; He, J.; Shahnia, S.; Reardon, C.; Krauss, T.F.; Steel, M.J.; Clark, A.S.; Eggleton, B.J.

2013-01-01

308

GRB 110709A, 111117A, AND 120107A: FAINT HIGH-ENERGY GAMMA-RAY PHOTON EMISSION FROM FERMI-LAT OBSERVATIONS AND DEMOGRAPHIC IMPLICATIONS  

SciTech Connect

Launched on 2008 June 11, the Large Area Telescope (LAT) instrument on board the Fermi Gamma-ray Space Telescope has provided a rare opportunity to study high-energy photon emission from gamma-ray bursts (GRBs). Although the majority of such events (27) have been identified by the Fermi-LAT Collaboration, four were uncovered by using more sensitive statistical techniques. In this paper, we continue our earlier work by finding three more GRBs associated with high-energy photon emission, GRB 110709A, 111117A, and 120107A. To systematize our matched filter approach, a pipeline has been developed to identify these objects in nearly real time. GRB 120107A is the first product of this analysis procedure. Despite the reduced threshold for identification, the number of GRB events has not increased significantly. This relative dearth of events with low photon number prompted a study of the apparent photon number distribution. We find an extremely good fit to a simple power law with an exponent of -1.8 {+-} 0.3 for the differential distribution. As might be expected, there is a substantial correlation between the number of lower energy photons detected by the Gamma-ray Burst Monitor (GBM) and the number observed by LAT. Thus, high-energy photon emission is associated with some but not all of the brighter GBM events. Deeper studies of the properties of the small population of high-energy emitting bursts may eventually yield a better understanding of these entire phenomena.

Zheng Weikang; Akerlof, Carl W.; McKay, Timothy A. [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States); Pandey, Shashi B. [Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263129 (India); Zhang Binbin [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Zhang Bing [Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154 (United States); Sakamoto, Takanori, E-mail: zwk@umich.edu [Center for Research and Exploration in Space Science and Technology (CRESST), NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-09-01

309

Nonclassicality in phase by breaking classical bounds on statistics  

NASA Astrophysics Data System (ADS)

We derive upper bounds on the statistics of phase and phase difference that are satisfied by all classical states. They are obtained by finding the maximum projection of classical states on phase states. For a single-mode phase, meaningful bounds are obtained conditioned to a fixed mean number of photons. We also derive classical bounds for the projection on phase-coherent states, discussing their relation with phase-state bounds within the context of analytic representations. We find states with nonclassical phase properties disclosed by the violation of these classical bounds. These are quadrature and SU(2) squeezed states and phase-coherent states.

Martín, Daniel; Luis, Alfredo

2010-09-01

310

Number Sense  

NSDL National Science Digital Library

Hacker has given you a challenge. Heâll run his number machine to create a number. Then youâll get three numbers between one and nine. The challenge is to make a number that is larger than the one on Hackerâs machine. Be careful though--Hacker will give you numbers that canât be bigger than his!

2008-01-01

311

Using high-power lasers for detection of elastic photon-photon scattering  

E-print Network

The properties of four-wave interaction via the nonlinear quantum vacuum is investigated. The effect of the quantum vacuum is to generate photons with new frequencies and wave vectors, due to elastic photon-photon scattering. An expression for the number of generated photons is derived and using state-of-the-art laser data it is found that the number of photons can reach detectable levels. In particular, the prospect of using the high repetition Astra Gemini system at the Rutherford Appleton Laboratory is discussed. The problem of noise sources is reviewed, and it is found that the noise level can be reduced well below the signal level. Thus, detection of elastic photon-photon scattering may for the first time be achieved.

E. Lundstrom; G. Brodin; J. Lundin; M. Marklund; R. Bingham; J. Collier; J. T. Mendonca; P. Norreys

2005-10-06

312

Quantum Electrodynamics of Intense Photon Beams  

Microsoft Academic Search

A new formula for induced transition amplitudes in intense photon beams is derived which relates the photon-number description to the coherent-field description. According to this formula transition amplitudes describing processes in which m photons are added to the intense one-mode beam or subtracted from that beam are equal to the Fourier coefficients of the corresponding amplitude in the external field,

I. Bialynicki-Birula; Z. Bialynicka-Birula

1973-01-01

313

Morbidity statistics  

PubMed Central

This paper is based on an analysis of questionnaires sent to the health ministries of Member States of WHO asking for information about the extent, nature, and scope of morbidity statistical information. It is clear that most countries collect some statistics of morbidity and many countries collect extensive data. However, few countries relate their collection to the needs of health administrators for information, and many countries collect statistics principally for publication in annual volumes which may appear anything up to 3 years after the year to which they refer. The desiderata of morbidity statistics may be summarized as reliability, representativeness, and relevance to current health problems. PMID:5306722

Smith, Alwyn

1969-01-01

314

Number Line  

NSDL National Science Digital Library

This iOS app helps students to visualize number sentences and create models for addition, subtractions, multiplication, and division. The number line can be adjusted to represent multiples of numbers from one to one hundred.

Clarity Innovations, Inc.

2013-11-22

315

Multimode One-Way Waveguides of Large Chern Numbers  

E-print Network

Current experimental realizations of the quantum anomalous Hall phase in both electronic and photonic systems have been limited to a Chern number of one. In photonics, this corresponds to a single-mode one-way edge waveguide. ...

Skirlo, Scott A.

316

Chaos due to parametric excitation: phase space symmetry and photon correlations  

E-print Network

We discuss dissipative chaos showing symmetries in the phase space and nonclassical statistics for a parametrically driven nonlinear Kerr resonator (PDNR). In this system an oscillatory mode is created in the process of degenerate down-conversion of photons under interaction with a train of external Gaussian pulses. For chaotic regime we demonstrate, that the Poincar\\'e section showing a strange attractor, as well as the resonator mode contour plots of the Wigner functions display two-fold symmetry in the phase space. We show that quantum-to-classical correspondence is strongly violated for some chaotic regimes of the PDNR. Considering the second-order correlation function we show that the high-level of photons correlation leading to squeezing in the regular regime strongly decreases if the system transits to the chaotic regime. Thus, observation of the photon-number correlation allows to extract information about the chaotic regime.

T. V. Gevorgyan; G. H. Hovsepyan; A. R. Shahinyan; G. Yu. Kryuchkyan

2014-07-29

317

Statistics Anxiety and Business Statistics: The International Student  

ERIC Educational Resources Information Center

Does the international student suffer from statistics anxiety? To investigate this, the Statistics Anxiety Rating Scale (STARS) was administered to sixty-six beginning statistics students, including twelve international students and fifty-four domestic students. Due to the small number of international students, nonparametric methods were used to…

Bell, James A.

2008-01-01

318

Statistical Diversions  

ERIC Educational Resources Information Center

In this article, the authors focus on hypothesis testing--that peculiarly statistical way of deciding things. Statistical methods for testing hypotheses were developed in the 1920s and 1930s by some of the most famous statisticians, in particular Ronald Fisher, Jerzy Neyman and Egon Pearson, who laid the foundations of almost all modern methods of…

Petocz, Peter; Sowey, Eric

2008-01-01

319

Number Factory  

NSDL National Science Digital Library

This interactive game develops fluency and flexibility with whole number operations. In each round the player is given 4 single-digit whole numbers, presented in the context of a factory. The player uses each number exactly once with the interactive calculator to arrive as close as possible to a given target number.

Doorman, Michiel

2003-01-01

320

Number Sense  

NSDL National Science Digital Library

In this online math game from Cyberchase, learners play against Hacker in a place value game. The goal is to make a number bigger than the one created by Hacker's number machine. Learners select the numbers in the order in which they want them to go into their machine. The challenge is to either make a number larger than the one on Hacker's machine or realize that it's impossible to make a number bigger than Hacker's, no matter what the combination.

Wnet

2011-01-01

321

UCLA Statistics Series  

NSDL National Science Digital Library

The University of California Los Angeles Statistics Series presents a collection of more than 250 preprints covering a wide array of statistical topics, such as descriptive multivariate analysis, advanced linear models, survey construction and analysis, teaching statistics, and much more. The preprints are arranged by paper number only, hence users must browse the entire list to locate relevant items. Approximately half of the full-text preprints are accessible in HTML, .pdf, or postscript formats. To access preprints not available electronically, users must contact the authors of the papers; author addresses are provided.

322

Resonance formation in photon-photon collisions  

SciTech Connect

Recent experimental progress on resonance formation in photon-photon collisions is reviewed with particular emphasis on the pseudoscalar and tensor nonents and on the ..gamma gamma..* production of spin-one resonances. 37 refs., 17 figs., 5 tabs.

Gidal, G.

1988-08-01

323

Statistical Laboratory & Department of Statistics  

E-print Network

will coordinate the teaching of the first two courses in business statistics. The undergraduate program continues and statistical methodology in the nutritional sciences. We were also very pleased to secure a permanent lecturer reviewing achievements of the past seven years and planning for the future. A written report was submitted

324

Statistics Clinic  

NASA Technical Reports Server (NTRS)

Do you have elevated p-values? Is the data analysis process getting you down? Do you experience anxiety when you need to respond to criticism of statistical methods in your manuscript? You may be suffering from Insufficient Statistical Support Syndrome (ISSS). For symptomatic relief of ISSS, come for a free consultation with JSC biostatisticians at our help desk during the poster sessions at the HRP Investigators Workshop. Get answers to common questions about sample size, missing data, multiple testing, when to trust the results of your analyses and more. Side effects may include sudden loss of statistics anxiety, improved interpretation of your data, and increased confidence in your results.

Feiveson, Alan H.; Foy, Millennia; Ploutz-Snyder, Robert; Fiedler, James

2014-01-01

325

Rainbow statistics  

E-print Network

Non-commutative quantum field theories and their global quantum group symmetries provide an intriguing attempt to go beyond the realm of standard local quantum field theory. A common feature of these models is that the quantum group symmetry of their Hilbert spaces induces additional structure in the multiparticle states which reflects a non-trivial momentum-dependent statistics. We investigate the properties of this "rainbow statistics" in the particular context of $\\kappa$-quantum fields and discuss the analogies/differences with models with twisted statistics.

Michele Arzano; Dario Benedetti

2008-09-04

326

Light-shift-induced photonic nonlinearities  

E-print Network

We propose a new method to produce self- and cross-Kerr photonic nonlinearities, using light-induced Stark shifts due to the interaction of a cavity mode with atoms. The proposed experimental set-up is considerably simpler than in previous approaches, while the strength of the nonlinearity obtained with a single atom is the same as in the setting based on electromagnetically induced transparency. Furthermore our scheme can be applied to engineer effective photonic nonlinear interactions whose strength increases with the number of atoms coupled to the cavity mode, leading to photon-photon interactions several orders of magnitude larger than previously considered possible.

Fernando G. S. L. Brandao; Michael J. Hartmann; Martin B. Plenio

2007-05-16

327

Entangled-photon compressive ghost imaging  

SciTech Connect

We have experimentally demonstrated high-resolution compressive ghost imaging at the single-photon level using entangled photons produced by a spontaneous parametric down-conversion source and using single-pixel detectors. For a given mean-squared error, the number of photons needed to reconstruct a two-dimensional image is found to be much smaller than that in quantum ghost imaging experiments employing a raster scan. This procedure not only shortens the data acquisition time, but also suggests a more economical use of photons for low-light-level and quantum image formation.

Zerom, Petros [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Chan, Kam Wai Clifford [Rochester Optical Manufacturing Company, 1260 Lyell Avenue, Rochester, New York 14606 (United States); Howell, John C. [Department of Physics and Astronomy, University of Rochester, 500 Wilson Boulevard, Rochester, New York 14627 (United States); Boyd, Robert W. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Department of Physics and Astronomy, University of Rochester, 500 Wilson Boulevard, Rochester, New York 14627 (United States); Department of Physics, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5 (Canada)

2011-12-15

328

/ Photon Mapping Second  

E-print Network

Calculating Radiance at an intersection point: 1.Gather the N nearest photons using the nearest neighbor search function on the photon map. 2.Let S be the sphere that contains these N photons. 3.For each photon, divide the amount of flux (real photons) that the photon represents by the area of S and multiply by the BRDF applied to that photon. 4. The sum of those results for each photon represents total surface radiance returned by the surface intersection in the direction of the ray that struck it.Nice image to offset all that text

Image Henrik; Wann Jensen; Image Henrik; Wann Jensen More

329

General displaced SU(1, 1) number states: Revisited  

NASA Astrophysics Data System (ADS)

The most general displaced number states, based on the bosonic and an irreducible representation of the Lie algebra symmetry of su(1, 1) and associated with the Calogero-Sutherland model are introduced. Here, we utilize the Barut-Girardello displacement operator instead of the Klauder-Perelomov counterpart, to construct new kind of the displaced number states which can be classified in nonlinear coherent states regime, too, with special nonlinearity functions. They depend on two parameters, and can be converted into the well-known Barut-Girardello coherent and number states, respectively, depending on which of the parameters equal to zero. A discussion of the statistical properties of these states is included. Significant are their squeezing properties and anti-bunching effects which can be raised by increasing the energy quantum number. Depending on the particular choice of the parameters of the above scenario, we are able to determine the status of compliance with flexible statistics. Major parts of the issue is spent on something that these states, in fact, should be considered as new kind of photon-added coherent states, too. Which can be reproduced through an iterated action of a creation operator on new nonlinear Barut-Girardello coherent states. Where the latter carry, also, outstanding statistical features.

Dehghani, A.

2014-04-01

330

Large numbers hypothesis. II - Electromagnetic radiation  

NASA Technical Reports Server (NTRS)

This paper develops the theory of electromagnetic radiation in the units covariant formalism incorporating Dirac's large numbers hypothesis (LNH). A direct field-to-particle technique is used to obtain the photon propagation equation which explicitly involves the photon replication rate. This replication rate is fixed uniquely by requiring that the form of a free-photon distribution function be preserved, as required by the 2.7 K cosmic radiation. One finds that with this particular photon replication rate the units covariant formalism developed in Paper I actually predicts that the ratio of photon number to proton number in the universe varies as t to the 1/4, precisely in accord with LNH. The cosmological red-shift law is also derived and it is shown to differ considerably from the standard form of (nu)(R) - const.

Adams, P. J.

1983-01-01

331

Two-photon spectra of quantum emitters  

NASA Astrophysics Data System (ADS)

We apply our recently developed theory of frequency-filtered and time-resolved N-photon correlations (del Valle et al 2012 Phys. Rev. Lett. 109 183601) to study the two-photon spectra of a variety of systems of increasing complexity: single-mode emitters with two limiting statistics (one harmonic oscillator or a two-level system) and the various combinations that arise from their coupling. We consider both the linear and nonlinear regimes under incoherent excitation. We find that even the simplest systems display a rich dynamics of emission, not accessible by simple single-photon spectroscopy. In the strong coupling regime, two-photon emission processes involving virtual states are revealed. Furthermore, two general results are unravelled by two-photon correlations with narrow linewidth detectors: (i) filtering-induced bunching and (ii) breakdown of the semi-classical theory. We show how to overcome the latter in a fully quantized picture.

Gonzalez-Tudela, Alejandro; Laussy, Fabrice P.; Tejedor, Carlos; Hartmann, Michael J.; del Valle, Elena

2013-03-01

332

Photonic analogue of quantum spin Hall effect  

E-print Network

Symmetry-protected photonic topological insulator exhibiting robust pseudo-spin-dependent transportation, analogous to quantum spin Hall (QSH) phases and topological insulators, are of great importance in fundamental physics. Such transportation robustness is protected by time-reversal symmetry. Since electrons (fermion) and photons (boson) obey different statistics rules and associate with different time-reversal operators (i.e., Tf and Tb, respectively), whether photonic counterpart of Kramers degeneracy is topologically protected by bosonic Tb remains unidentified. Here, we construct the degenerate gapless edge states of two photonic pseudo-spins (left/right circular polarizations) in the band gap of a two-dimensional photonic crystal with strong magneto-electric coupling. We further demonstrated that the topological edge states are in fact protected by Tf rather than commonly believed Tb and their pseudo-spin dependent transportation is robust against Tf invariant impurities, discovering for the first tim...

He, Cheng; Liu, Xiao-ping; Lu, Ming-Hui; Chen, Yulin; Feng, Liang; Chen, Yan-Feng

2014-01-01

333

Injury Statistics  

MedlinePLUS

... 2012 1998 Electrocutions Associated With Consumer Products July 17, 2012 2000 Electrocutions Associated with Consumer Products (9999) ... Furniture and Decor Injury Statistics Other Sports July 17, 2012 Unpowered Scooters July 10, 2012 Trampolines May ...

334

Localized photonic modes in photonic crystal heterostructures  

Microsoft Academic Search

In this work, interface modes of two-dimensional photonic crystal heterostructures have been investigated by usage of the supercell method. The photonic crystal heterostructure is made of two photonic crystals with square symmetry in which one of them is composed of circular dielectric rods in air background and the other one is constructed by drilled square holes in dielectric. It is

Mohsen Mehrabi; Ali Soltani-Vala; Jamal Barvestani

2011-01-01

335

Statistical Mechanics  

Microsoft Academic Search

We review and further develop a mathematical framework for non-equilibrium quantum statistical mechanics recently proposed in (JP4, JP5, JP6, Ru3, Ru4, Ru5, Ru6). In the alge- braic formalism of quantum statistical mechanics we introduce notions of non-equilibrium steady states, entropy production and heat fluxes, and study their properties. Our basic paradigm is a model of a small (finite) quantum system

V. Jaksi ´; C.-A. Pillet

1937-01-01

336

Number Cruncher  

NSDL National Science Digital Library

This Science NetLinks interactive game helps students increase their logic and decision making skills by challenging a player to consider a series of mathematical processes to find a path from a starting number to a goal number in a math maze. The activity appears as a 5x5 matrix of numbers, each of which has an operation symbol next to it, indicating whether it will be added to, subtracted from, or multiplied by the previous number. Starting in the center with a given number, players choose an adjoining number to complete the next step and they proceed until successfully reaching the goal number or until they have run out of usable numbers on the game board. To add an additional challenge to the game, a player can limit each level to reaching the target in seven or fewer steps.

2011-10-13

337

NUMBER SENSE  

NSDL National Science Digital Library

Students will practice counting to 100, making numbers with base ten blocks and practicing ordinal numbers! Math is FUN! Lets have fun practicing counting to 100 ! Click when you are ready!Counting Now that you have practiced counting to 100, lets use the base ten blocks to make the number that is on the screen. Click when you are ready!Working with Base Ten Blocks We have now practiced counting and making numbers, lets ...

Simpson, Ms.

2007-10-27

338

Inverting the quantum cloning of photons  

E-print Network

We propose an experiment where a photon is first cloned using stimulated parametric down-conversion, making many (imperfect) copies, and then the cloning transformation is inverted, regenerating the original photon while destroying the copies. Focusing on the case where the initial photon is entangled with another photon, we study the conditions under which entanglement can be proven in the final state. The proposed experiment would provide a clear demonstration that quantum information is preserved in phase-covariant quantum cloning. It would furthermore allow an experimental proof for micro-macro entanglement in the intermediate multi-photon state. Finally it might form the basis of a quantum detection technique for small differences in transmission (e.g. in low-contrast biological samples), whose sensitivity scales better with the number of photons used than a classical transmission measurement.

Raeisi, Sadegh; Simon, Christoph

2011-01-01

339

Number Factory  

NSDL National Science Digital Library

This interactive Java applet promotes number sense, estimation, and provides practice with order of operations. The player's goal is to make a numerical expression using the four given numbers and the four basic operations with the result being the target number (or as close as they can get to it). The student can also use brackets in their calculation.

Doorman, Michiel

2012-01-07

340

Letter Optical quantum random number generator  

Microsoft Academic Search

A physical random number generator based on the intrinsic randomness of quantum mechanics is described. The random events are realized by the choice of single photons between the two outputs of a beamsplitter. We present a simple device, which minimizes the impact of the photon counters' noise, dead-time and after pulses.

Andre Stefanov; Nicolas Gisin; Olivier Guinnard; Laurent Guinnard; Hugo Zbinden

2000-01-01

341

Photon sorters and QND detectors using single photon emitters  

E-print Network

We discuss a new method for realizing number-resolving and non-demolition photo detectors by strong coupling of light to individual single photon emitters, which act as strong optical non-linearities. As a specific application we show how these elements can be integrated into an error-proof Bell state analyzer, whose efficiency exceeds the best possible performance with linear optics even for a modest atom-field coupling. The methods are error-proof in the sense that every detection event unambiguously projects the photon state onto a Fock or Bell state.

D. Witthaut; M. D. Lukin; A. S. Sørensen

2010-07-19

342

Mechanically Tunable Negative-Index Photonic Crystal Lens  

E-print Network

Mechanically Tunable Negative-Index Photonic Crystal Lens Volume 2, Number 6, December 2010 Y. Cui;Mechanically Tunable Negative-Index Photonic Crystal Lens Y. Cui,1;2 V. A. Tamma,1 J.-B. Lee,2 and W. Park1 1 systems (MEMS)-enabled mechanically tunable negative-index photonic crystal lens, which was comprised of 2

Lee, Jeong-Bong

343

Using single photons to improve fiber optic communication systems  

NASA Astrophysics Data System (ADS)

We show how to generate, encode, transmit and detect single photons. By using single photons we can address two of the more challenging problems that communication engineers face nowadays: capacity and security. Indeed, by decreasing the number of photons used to encode each bit, we can efficiently explore the full capacity to carry information of optical fibers, and we can guarantee privacy at the physical layer. We present results for single and entangled photon generation. We encode information in the photons polarization and after transmission we retrieve that information. We discuss the impact of fiber birefringence on the photons polarization.

Pinto, Armando N.; Silva, Nuno A.; Almeida, Álvaro J.; Muga, Nelson J.

2014-08-01

344

Photon-Photon Interactions via Rydberg Blockade  

E-print Network

We develop the theory of light propagation under the conditions of electromagnetically induced transparency (EIT) in systems involving strongly interacting Rydberg states. Taking into account the quantum nature and the spatial propagation of light, we analyze interactions involving few-photon pulses. We demonstrate that this system can be used for the generation of nonclassical states of light including trains of single photons with an avoided volume between them, for implementing photon-photon quantum gates, as well as for studying many-body phenomena with strongly correlated photons.

Alexey V. Gorshkov; Johannes Otterbach; Michael Fleischhauer; Thomas Pohl; Mikhail D. Lukin

2011-03-18

345

Photon-Photon Interactions via Rydberg Blockade  

SciTech Connect

We develop the theory of light propagation under the conditions of electromagnetically induced transparency in systems involving strongly interacting Rydberg states. Taking into account the quantum nature and the spatial propagation of light, we analyze interactions involving few-photon pulses. We show that this system can be used for the generation of nonclassical states of light including trains of single photons with an avoided volume between them, for implementing photon-photon gates, as well as for studying many-body phenomena with strongly correlated photons.

Gorshkov, Alexey V. [Institute for Quantum Information, California Institute of Technology, Pasadena, California 91125 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); Otterbach, Johannes [Department of Physics and Research Center OPTIMAS, Technische Universitaet Kaiserslautern, 67663, Kaiserslautern (Germany); Fleischhauer, Michael [Department of Physics and Research Center OPTIMAS, Technische Universitaet Kaiserslautern, 67663, Kaiserslautern (Germany); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); Pohl, Thomas [Max Planck Institute for the Physics of Complex Systems, 01187 Dresden (Germany); Lukin, Mikhail D. [Physics Department, Harvard University, Cambridge, Massachusetts 02138 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)

2011-09-23

346

Supernova brightening from chameleon-photon mixing  

SciTech Connect

Measurements of standard candles and measurements of standard rulers give an inconsistent picture of the history of the universe. This discrepancy can be explained if photon number is not conserved as computations of the luminosity distance must be modified. I show that photon number is not conserved when photons mix with chameleons in the presence of a magnetic field. The strong magnetic fields in a supernova mean that the probability of a photon converting into a chameleon in the interior of the supernova is high, this results in a large flux of chameleons at the surface of the supernova. Chameleons and photons also mix as a result of the intergalactic magnetic field. These two effects combined cause the image of the supernova to be brightened resulting in a model which fits both observations of standard candles and observations of standard rulers.

Burrage, C. [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, Cambridge, CB2 0WA (United Kingdom)

2008-02-15

347

Optimization of a photon rejecter to separate electronic noise in a photon-counting detector  

NASA Astrophysics Data System (ADS)

Photon-counting-based X-ray imaging technology provides the capability to count individual photons and to characterize photon energies. The cadmium telluride (CdTe)-based photon-counting detector is limited in capability, however, under a high X-ray flux. A photon rejecter composed of aluminum, for example, can reduce this limitation by modulating the incident number of photons. In addition to this function, the optimal photon rejecter can separate electronic noise, which degrades image quality. The aim of this work was to optimize a photon rejecter for high-quality image acquisition by removing electronic noise from the actual pulse signal. The images and spectra were acquired using a micro-focus X-ray source with a CdTe-based photon-counting detector. We acquired data with various types of photon-rejecter materials composed of aluminum (Al) and iodine at three different tube voltages (50, 70, and 90 kVp). A phantom composed of high-atomic-number materials was imaged to evaluate the efficiency of the photon rejecter. Photon rejecters composed of 1-mm Al, 10-mm Al, and a combination of 10-mm Al and iodine provided optimum capability at 50, 70, and 90 kVp, respectively. Each optimal combination of photon-rejecter material and voltage effectively separated electronic noise from the actual pulse signal and gave the highest contrast-tonoise ratio for materials on the image. These optimized types of photon rejecters can effectively discriminate electronic noise and improve image quality at different tube voltages.

Cho, Hyo-Min; Choi, Yu-Na; Lee, Seung-Wan; Lee, Young-Jin; Ryu, Hyun-Ju; Kim, Hee-Joung

2012-12-01

348

Optomechanical photon shuttling between photonic cavities.  

PubMed

Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave mixing between photons and phonons, and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong non-local effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a multicavity optomechanical device in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of this 'photon see-saw', are modulated antisymmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation, which strongly modulates the inter-cavity coupling and shuttles photons to the other empty cavity during every oscillation cycle in a well-regulated fashion. PMID:25240675

Li, Huan; Li, Mo

2014-11-01

349

Optomechanical photon shuttling between photonic cavities  

E-print Network

Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave-mixing between photons and phonons and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong nonlocal effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a novel multi-cavity optomechanical device: a "photon see-saw", in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of the see-saw, are modulated anti-symmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation which strongly modulates the inter-cavity coupling and shuttles photons to the other...

Li, Huan

2014-01-01

350

Compressive Object Tracking using Entangled Photons  

E-print Network

We present a compressive sensing protocol that tracks a moving object by removing static components from a scene. The implementation is carried out on a ghost imaging scheme to minimize both the number of photons and the number of measurements required to form a quantum image of the tracked object. This procedure tracks an object at low light levels with fewer than 3% of the measurements required for a raster scan, permitting us to more effectively use the information content in each photon.

Omar S. Magaña-Loaiza; Gregory A. Howland; Mehul Malik; John C. Howell; Robert W. Boyd

2013-06-10

351

Simplified description of unsaturated two-photon absorption. II - Squeezing and enhanced photon antibunching  

Microsoft Academic Search

The summation of the short-time expansion for two-photon absorption is extended to phase-dependent expectation values in order to calculate squeezing and the influence of squeezing on enhancement of antibunching. The treatment is well suited for great photon numbers and arbitrary absorption strengths and delivers simple analytical expressions. It is shown that squeezing is responsible for the possibility of enhanced photon

A. Bandilla

1986-01-01

352

Protecting sing-photon multi-mode W state from photon loss  

E-print Network

Single-photon entanglement is of major importance in current quantum communications. However, it is sensitive to photon loss. In this paper, we discuss the protection of single-photon multi-mode W state with noiseless linear amplification. It is shown that the amplification factor is only decided with the transmission coefficient of the variable fiber beam splitters, and it does not change with the number of the spatial mode. This protocol may be useful in current quantum information processing.

Yu-Bo Sheng; Yang Ou-Yang; Lan Zhou; Lei Wang

2014-02-08

353

photonics.com  

NSDL National Science Digital Library

It's everything photonics! From the the publishers of Photonics Spectra magazine this website will help you gain technical and practical information for every aspect of the global industry, integrating all segments of photonics: optics, lasers, imaging, fiber optics, electro-optics as well as photonic component manufacturing.

Publishing, Laurin

354

Photonic switching fabrics  

Microsoft Academic Search

The strengths and limitations of the photonic technology are reviewed, beginning with the temporal bandwidth limitations of photonic devices and then focusing on spatial bandwidth, commonly referred to as the parallelism of optics, and how it can be used in photonic fabrics. Some of the proposed photonic switching fabrics that are based on guided-wave devices are discussed, comprising switching fabrics

H. Scott Hinton

1990-01-01

355

Sub-Poissonian statistics of Rydberg-interacting dark-state polaritons.  

PubMed

We observe individual dark-state polaritons as they propagate through an ultracold atomic gas involving Rydberg states coupled via an electromagnetically induced transparency resonance. Strong long-range interactions between Rydberg excitations give rise to a blockade between polaritons, resulting in large optical nonlinearities and modified polariton number statistics. By combining optical imaging and high-fidelity detection of the Rydberg polaritons we investigate both aspects of this coupled atom-light system. We map out the full nonlinear optical response as a function of atomic density and follow the temporal evolution of polaritons through the atomic cloud. In the blockade regime, the statistical fluctuations of the polariton number drop well below the quantum noise limit. The low level of fluctuations indicates that photon correlations modified by the strong interactions have a significant backaction on the Rydberg atom statistics. PMID:25167407

Hofmann, C S; Günter, G; Schempp, H; Robert-de-Saint-Vincent, M; Gärttner, M; Evers, J; Whitlock, S; Weidemüller, M

2013-05-17

356

Quantum theory for generation of nonclassical photon pairs by a medium with collective atomic memory  

SciTech Connect

We present the quantum theory for creation of collective atomic memory and generation of nonclassically correlated photon pairs from an ensemble via the protocol of Duan et al. [Nature (London) 414, 413 (2001)]. The temporal evolution of photon numbers, photon statistics, and cross-correlation between the Stokes and anti-Stokes fields is found by solving the equation of motion for atomic spin-wave excitations. We consider a low-finesse cavity model with collectively enhanced signal-to-noise ratio, which remains still considerably large in the free-space limit. Our results describe analytically the dependence of quantum correlations on spin decoherence time and time delay between the write and read lasers and reproduce the observed data very well including the generated pulse shapes, strong violation of Cauchy-Schwarz inequality and conditional generation of anti-Stokes single-photon pulse. The approach we developed may be used also for quantum description of storage and retrieval of quantum information, especially when the statistical properties of nonclassical pulses are studied.

Sisakyan, Narek; Malakyan, Yuri [Institute for Physical Research, Armenian National Academy of Sciences, Ashtarak-2, 378410 (Armenia)

2005-10-15

357

Engineering Statistics From "Engineering Statistics" , Top &  

E-print Network

Engineering Statistics From "Engineering Statistics" , Top & Wiley, Prapaisri & Pongchanun 2 From "Engineering Statistics" , Top & Wiley, Prapaisri & Pongchanun 3 " "(Sample) (Sampling) ""(Population) " "(Statistics) ""(Parameter) From "Engineering Statistics" , Top & Wiley, Prapaisri

Kovintavewat, Piya

358

Topological Photonic States  

NASA Astrophysics Data System (ADS)

As exotic phenomena in optics, topological states in photonic crystals have drawn much attention due to their fundamental significance and great potential applications. Because of the broken time-reversal symmetry under the influence of an external magnetic field, the photonic crystals composed of magneto-optical materials will lead to the degeneracy lifting and show particular topological characters of energy bands. The upper and lower bulk bands have nonzero integer topological numbers. The gapless edge states can be realized to connect two bulk states. This topological photonic states originated from the topological property can be analogous to the integer quantum Hall effect in an electronic system. The gapless edge state only possesses a single sign of gradient in the whole Brillouin zone, and thus the group velocity is only in one direction leading to the one-way energy flow, which is robust to disorder and impurity due to the nontrivial topological nature of the corresponding electromagnetic states. Furthermore, this one-way edge state would cross the Brillouin center with nonzero group velocity, where the negative-zero-positive phase velocity can be used to realize some interesting phenomena such as tunneling and backward phase propagation. On the other hand, under the protection of time-reversal symmetry, a pair of gapless edge states can also be constructed by using magnetic-electric coupling meta-materials, exhibiting Fermion-like spin helix topological edge states, which can be regarded as an optical counterpart of topological insulator originating from the spin-orbit coupling. The aim of this article is to have a comprehensive review of recent research literatures published in this emerging field of photonic topological phenomena. Photonic topological states and their related phenomena are presented and analyzed, including the chiral edge states, polarization dependent transportation, unidirectional waveguide and nonreciprocal optical transmission, all of which might lead to novel applications such as one-way splitter, optical isolator and delay line. In addition, the possible prospect and development of related topics are also discussed.

He, Cheng; Lin, Liang; Sun, Xiao-Chen; Liu, Xiao-Ping; Lu, Ming-Hui; Chen, Yan-Feng

2014-01-01

359

Optimization of hardware-based photon rejecter to separate electronic noise in the photon counting detector  

NASA Astrophysics Data System (ADS)

The cadmium telluride (CdTe)-based photon-counting detector is limited in capability under a high x-ray flux. A photon rejecter composed of aluminum, for example, can reduce this limitation by modulating the incident number of photons. In addition to this function, the optimal photon rejecter can separates electronic noise. The aim of this work was to optimize the photon rejecter for high quality image acquisition by removing electronic noise from the actual pulse signal. We acquired data with various types of photon rejecter materials composed of aluminum (Al) and iodine at three different tube voltages (50, 70 and 90 kVp). A phantom composed of high atomic number materials was imaged to evaluate the efficiency of the photon rejecter. Photon rejecters composed of 1-mm Al, 10-mm Al, and a combination of 10-mm Al and iodine provided optimum capability at 50, 70 and 90 kVp, respectively. Each optimal combination of photon rejecter material and voltage effectively separated electronic noise from the actual pulse signal and gave highest contrast for materials on the image. These optimized types of photon rejecter can effectively discriminate electronic noise and improve image quality according to the different tube voltages.

Cho, Hyo-Min; Kim, Hee-Joung; Choi, Yu-Na; Lee, Seung-Wan; Lee, Young-Jin; Ryu, Hyun-Ju

2012-03-01

360

Library Research and Statistics. Research on Libraries and Librarianship in 2002; Number of Libraries in the United States and Canada; Highlights of NCES Surveys; Library Acquisition Expenditures, 2001-2002: U.S. Public, Academic, Special, and Government Libraries; LJ Budget Report: A Precarious Holding Pattern; Price Indexes for Public and Academic Libraries; Library Buildings 2002: The Building Buck Doesn't Stop Here.  

ERIC Educational Resources Information Center

Includes seven reports that discuss research on libraries and librarianship, including academic, public, and school libraries; awards and grants; number of libraries in the United States and Canada; National Center for Education Statistics results; library expenditures for public, academic, special, and government libraries; library budgets; price…

Lynch, Mary Jo; Oder, Norman; Halstead, Kent; Fox, Bette-Lee

2003-01-01

361

Multidimensional Hermite polynomials and photon distribution for polymode mixed light  

E-print Network

For N-mode light described by the Wigner function of generic Gaussian form the photon distribution function is obtained explicitly and expressed in terms of Hermite polynomial of $2N$ variables with equal pairs of indices.The mean values and dispersions of photon numbers are obtained for this generic mixed state.Generating function for photon distribution is obtained explicitly. The expression for $N$-mode photon distribution function for squeezed photon number states in terms of Hermite polynomials of $2N$ variables and for squeezed coherent states in terms of Hermite polynomials of $N$ variables is discussed.

V. V. Dodonov; O. V. Man'ko; V. I. Man'ko

1993-08-07

362

Preparing Multi-photon Entangled State with Beam Splitter  

NASA Astrophysics Data System (ADS)

We propose a scheme for preparing multi-photon entangled state which is useful for sub-shot-noise sensitivity with beam splitter, where the entangled degree is measured by the reciprocal of the mean quantum Fisher information per particle (RMQFIP). The multi-photon entangled state can be prepared by adjusting the transmissivity of the beam splitter and the better multi-photon entangled state can be prepared by increasing the total number of photons.

Chen, Rong-Hua; Yi, Hong-Gang

2014-12-01

363

National Statistics Online  

NSDL National Science Digital Library

Perhaps you have a burning desire to find detailed statistical information about agriculture in Wales, or even about poverty in London's East End. All of this information can be found on the very thorough and usable National Statistics homepage, which provides information on Britain's economy, population, and society. Given the amount of information on the site, visitors would do well to look through the UK at a Glance area. Here they will find basic information on the gross domestic product, consumer spending, unemployment, and population estimates. Along with these aggregate figures for the entire nation, visitors can visit the neighborhood statistics section, where they can retrieve summary statistics for different locales around England and Wales. A number of fine reports based on the 2001 Census are also available for the general public's consideration, and they include considerations of the state of children's dental health to the provisioning of programs for the elderly.

364

Quantum phase transition of light in a one-dimensional photon-hopping-controllable resonator array  

NASA Astrophysics Data System (ADS)

We give a concrete experimental scheme for engineering the insulator-superfluid transition of light in a one-dimensional (1D) array of coupled superconducting stripline resonators. In our proposed architecture, the on-site interaction and the photon-hopping rate can be tuned independently by adjusting the transition frequencies of the charge qubits inside the resonators and at the resonator junctions, respectively, which permits us to systematically study the quantum phase transition of light in a complete parameter space. By combining the techniques of photon-number-dependent qubit transition and fast readout of the qubit state using a separate low-Q resonator mode, the statistical property of the excitations in each resonator can be obtained with a high efficiency. An analysis of the various decoherence sources and disorders shows that our scheme can serve as a guide to upcoming experiments involving a small number of coupled resonators.

Wu, Chun-Wang; Gao, Ming; Deng, Zhi-Jiao; Dai, Hong-Yi; Chen, Ping-Xing; Li, Cheng-Zu

2011-10-01

365

Number Grids and Number Triangles  

NSDL National Science Digital Library

Practice counting, counting by tens, place value, and fact families by entering your answers into the blank boxes; click the big blue and green buttons to check your work. Each of the five levels of Number Grid activities displays a section of a matrix containing a set of of consecutive whole numbers. A move from one number to the next within a row corresponds to a change of one; a move from one number to the next within a column refers to a change of ten. The three levels of Number Triangle activities provide practice with fact families and inverse relationships through flash cards. An addition/subtraction Number Triangle has two addends and a sum; a multiplication/division Number Triangle has two factors and a product.

Brown, Quincy; Fetter, Annie

2006-08-01

366

Tracking the Well-Being of Children and Youth at the State and Local Levels Using the Federal Statistical System. Occasional Paper Number 52. Assessing the New Federalism: An Urban Institute Program To Assess Changing Social Policies.  

ERIC Educational Resources Information Center

Over recent years, there has been an explosion in the collection of state and local level child and youth indicator data by federal statistical agencies and in the dissemination of those data through agency Web sites. This paper reviews these resources and provides information needed to access the data. Data sources are presented in five topical…

Brown, Brett V.

367

VOLUME 89, NUMBER 1 P H Y S I C A L R E V I E W L E T T E R S 1 JULY 2002 Statistical Theory of Asteroid Escape Rates  

E-print Network

of Asteroid Escape Rates Charles Jaffé,1,2,3 Shane D. Ross,1,2 Martin W. Lo,1,2 Jerrold Marsden,1 David to regulate the rate of escape of asteroids temporarily captured in circumplanetary orbits. The transition a statistical semianalytical theory for the rate of escape of asteroids temporarily captured by Mars. Theory

Ross, Shane

368

Uniiversity o Traffic Statist  

E-print Network

. The department's focus is to reduce the Community's fear of crime by the prevention of crime, the protection in this report were compiled through use of the Computer Aided Dispatch System and the Report Management System not allow for exact numbers to be captured. A new and improved system of computer entries and statistical

Van Stryland, Eric

369

International Justice Statistics  

NSDL National Science Digital Library

Provides statistical information from the UN Office for Drug Control and Crime Prevention as well as other participating research institutions. Provides links to UN data collections on crime and justice as well as links to justice department websites in a number of foreign countries.

370

Statistics of stable marriages  

NASA Astrophysics Data System (ADS)

In the stable marriage problem N men and N women have to be matched by pairs under the constraint that the resulting matching is stable. We study the statistical properties of stable matchings in the large N limit using both numerical and analytical methods. Generalizations of the model including singles and unequal numbers of men and women are also investigated.

Dzierzawa, Michael; Oméro, Marie-José

2000-11-01

371

Answer Changing and Statistics.  

ERIC Educational Resources Information Center

The impact of answer changing on the test scores of students studying educational statistics is investigated. The results show that students who make changes in their original responses significantly improve their overall test performance, and high-scoring students make a greater number of changes than low-scoring students. (Author/GSK)

Penfield, Douglas A.; Mercer, Maryann

1980-01-01

372

Data and Statistics  

MedlinePLUS

... About CDC.gov . Hemophilia Share Compartir Data & Statistics In the United States [ Read article ] Hemophilia affects 1 in 5,000 ... The exact number of people living with hemophilia in the United States is not known. A CDC study conducted in ...

373

Graded photonic quasicrystals.  

PubMed

We introduce graded photonic quasicrystals and investigate properties of such structures on the example of a Luneburg lens based on a dodecagonal photonic quasicrystal. It is shown that the graded photonic quasicrystal lens has better focusing properties as compared with the graded photonic crystal lens in a frequency range suitable for experimental realization. The proposed graded photonic quasicrystals can be used in optical systems where compact and powerful focusing elements are required. PMID:22739847

Dyachenko, Pavel N; Pavelyev, Vladimir S; Soifer, Victor A

2012-06-15

374

Software-based photon counting telemetry receiver for an infrared communications satellite  

NASA Astrophysics Data System (ADS)

Single photon per bit optical communication between ground stations and low earth orbit satellites will enable the secure global distribution of cryptographic keys. The communications satellite AO-40 contains an experimental infra-red payload consisting of a low power 835 nm laser diode transmitter coupled to a small fixed orientation telescope transmitting 400 baud Manchester encoded data [1]. The received signal levels are of the order of 10 photons/bit for an effective telescope aperture of diameter 100 mm [2]. They therefore offer a means of validating models of low photon number OOK signal propagation and detection in the presence of atmospheric turbulence, an issue relevant to free-space quantum communications. This paper describes the design, testing and implementation of a photon counting receiver for AO-40 signals using a Labview software platform to display received data, error statistics, detection and correction (using cyclic redundancy check code CRCC 32), and clock synchronization [3]. Signals are acquired with a 300 mm f/6.3 Schmidt-Cassegrain tracking telescope coupled by 100 micron multimode fibre to a silicon APD photon counting module. References 1. R. Purvinskis, Use of the fixed orientation optical transmitter on AO-40, Internal Report, Centre for Advanced Telecommunications and Quantum Electronics, University of Canberra, 2001. 2. A. Arora, Oscar 40: A Complete Link Analysis, University of Canberra BE (Hons) Report, November 2001. 3. A. Arora, Optical Modulator and Demodulator for the Oscar-40 Satellite, University of Canberra BE Project Report , November 2001.

Arora, Ashish; Edwards, Paul J.

2004-01-01

375

Lyapunov exponents for one-dimensional aperiodic photonic bandgap structures  

NASA Astrophysics Data System (ADS)

Existing in the "gray area" between perfectly periodic and purely randomized photonic bandgap structures are the socalled aperoidic structures whose layers are chosen according to some deterministic rule. We consider here a onedimensional photonic bandgap structure, a quarter-wave stack, with the layer thickness of one of the bilayers subject to being either thin or thick according to five deterministic sequence rules and binary random selection. To produce these aperiodic structures we examine the following sequences: Fibonacci, Thue-Morse, Period doubling, Rudin-Shapiro, as well as the triadic Cantor sequence. We model these structures numerically with a long chain (approximately 5,000,000) of transfer matrices, and then use the reliable algorithm of Wolf to calculate the (upper) Lyapunov exponent for the long product of matrices. The Lyapunov exponent is the statistically well-behaved variable used to characterize the Anderson localization effect (exponential confinement) when the layers are randomized, so its calculation allows us to more precisely compare the purely randomized structure with its aperiodic counterparts. It is found that the aperiodic photonic systems show much fine structure in their Lyapunov exponents as a function of frequency, and, in a number of cases, the exponents are quite obviously fractal.

Kissel, Glen J.

2011-10-01

376

The Single-Photon Router  

E-print Network

We have embedded an artificial atom, a superconducting "transmon" qubit, in an open transmission line and investigated the strong scattering of incident microwave photons ($\\sim6$ GHz). When an input coherent state, with an average photon number $N\\ll1$ is on resonance with the artificial atom, we observe extinction of up to 90% in the forward propagating field. We use two-tone spectroscopy to study scattering from excited states and we observe electromagnetically induced transparency (EIT). We then use EIT to make a single-photon router, where we can control to what output port an incoming signal is delivered. The maximum on-off ratio is around 90% with a rise and fall time on the order of nanoseconds, consistent with theoretical expectations. The router can easily be extended to have multiple output ports and it can be viewed as a rudimentary quantum node, an important step towards building quantum information networks.

Hoi, Io-Chun; Johansson, Göran; Palomaki, Tauno; Peropadre, Borja; Delsing, Per

2011-01-01

377

The Single-Photon Router  

E-print Network

We have embedded an artificial atom, a superconducting "transmon" qubit, in an open transmission line and investigated the strong scattering of incident microwave photons ($\\sim6$ GHz). When an input coherent state, with an average photon number $N\\ll1$ is on resonance with the artificial atom, we observe extinction of up to 90% in the forward propagating field. We use two-tone spectroscopy to study scattering from excited states and we observe electromagnetically induced transparency (EIT). We then use EIT to make a single-photon router, where we can control to what output port an incoming signal is delivered. The maximum on-off ratio is around 90% with a rise and fall time on the order of nanoseconds, consistent with theoretical expectations. The router can easily be extended to have multiple output ports and it can be viewed as a rudimentary quantum node, an important step towards building quantum information networks.

Io-Chun Hoi; C. M. Wilson; Göran Johansson; Tauno Palomaki; Borja Peropadre; Per Delsing

2011-03-09

378

Statistical Fun  

ERIC Educational Resources Information Center

Following the announcement last year that there will be no more math coursework assessment at General Certificate of Secondary Education (GCSE), teachers will in the future be able to devote more time to preparing learners for formal examinations. One of the key things that the author has learned when teaching statistics is that it makes for far…

Catley, Alan

2007-01-01

379

UK photonics in defence and security  

NASA Astrophysics Data System (ADS)

The UK is globally recognised as strong in Photonics. However its Photonics sector is fragmented and the size and sectors of interest have not previously been established. The UK government has instigated the formation of the Photonics Knowledge Transfer Network (PKTN) to bring the Photonics community together. The UK features in Defence & Security; Communications; Measurement; Medical Technology; Lighting; Solar Energy; Information Technology and Flat Panels. This expertise is scattered through out the UK in geographic areas each with a breadth of Photonic interests. The PKTN has mapped the UK capability in all Photonics sectors. This paper will present the capability of the Companies, Research Institutions and Infrastructure making up the Defence & Security Photonics scene in the UK. Large Defence companies in the UK are well known throughout the world. However, there are a large number of SMEs, which may not be as well known in the supply chain. These are being actively encouraged by the UK MoD to engage with the Defence & Security Market and shall be discussed here. The presentation will reference a number of organisations which help to fund and network the community, such as the Defence Technology Centres. In addition the Roadmap for Defence & Security in the UK, produced for the UK Photonics Strategy (July 2006) by the Scottish Optoelectronics Association will be described and the plans in taking it forward under the PKTN will be revealed.

Gracie, C.; Tooley, I.; Wilson, A.

2008-10-01

380

First measurement of the quark-to-photon fragmentation function  

Microsoft Academic Search

Earlier measurements at LEP of isolated hard photons in hadronic Z decays, attributed to radiation from primary quark pairs,\\u000a have been extended in the ALEPH experiment to include hard photon productioninside hadron jets. Events are selected where all particles combine democratically to form hadron jets, one of which contains a\\u000a photon with a fractional energyz?0.7. After statistical subtraction of non-prompt

Damir Buskulic; David William Casper; I. De Bonis; D. Decamp; P. Ghez; C. Goy; J.-P. Lees; A. Lucotte; M.-N. Minard; P. Odier; B. Pietrzyk; F. Ariztizabal; M. Chmeissani; J. M. Crespo; I. Efthymiopoulos; E. Fernandez; M. Fernandez-Bosman; V. Gaitan; Ll. Garrido; M. Martinez; S. Orteu; A. Pacheco; C. Padilla; Fabrizio Palla; A. Pascual; J. A. Perlas; F. Sanchez; F. Teubert; A. Colaleo; D. Creanza; M. de Palma; A. Farilla; G. Gelao; M. Girone; Giuseppe Iaselli; G. Maggi; M. Maggi; N. Marinelli; S. Natali; S. Nuzzo; A. Ranieri; G. Raso; F. Romano; F. Ruggieri; G. Selvaggi; L. Silvestris; P. Tempesta; G. Zito; X. Huang; J. Lin; Q. Ouyang; T. Wang; Y. Xie; R. Xu; S. Xue; J. Zhang; L. Zhang; W. Zhao; G. Bonvicini; M. Cattaneo; P. Comas; P. Coyle; H. Drevermann; A. Engelhardt; Roger W Forty; M. Frank; R. Hagelberg; J. Harvey; R. Jacobsen; P. Janot; B. Jost; J. Knobloch; Ivan Lehraus; C. Markou; E. B. Martin; P. Mato; H. Meinhard; Adolf G Minten; R. Miquel; T. Oest; P. Palazzi; J. R. Pater; J.-F. Pusztaszeri; F. Ranjard; P E Rensing; Luigi Rolandi; D. Schlatter; M. Schmelling; O. Schneider; W. Tejessy; I. R. Tomalin; A. Venturi; H W Wachsmuth; W. Wiedenmann; T. Wildish; W. Witzeling; J. Wotschack; Ziad J Ajaltouni; Maria Bardadin-Otwinowska; A. Barres; C. Boyer; A. Falvard; P. Gay; C. Guicheney; P. Henrard; J. Jousset; B. Michel; S. Monteil; J. C. Montret; D. Pallin; P. Perret; F. Podlyski; J. Proriol; J.-M. Rossignol; F. Saadi; Tom Fearnley; J. B. Hansen; J. D. Hansen; P. H. Hansen; B. S. Nilsson; A. Kyriakis; Errietta Simopoulou; I. Siotis; Anna Vayaki; K. Zachariadou; A. Blondel; G R Bonneaud; J. C. Brient; P. Bourdon; L. Passalacqua; A. Rougé; M. Rumpf; R. Tanaka; Andrea Valassi; M. Verderi; H L Videau; D. J. Candlin; M. I. Parsons; E. Focardi; G. Parrini; M. Corden; M C Delfino; C H Georgiopoulos; D. E. Jaffe; A. Antonelli; G. Bencivenni; G. Bologna; F. Bossi; P. Campana; G. Capon; V. Chiarella; G. Felici; P. Laurelli; G. Mannocchi; F. Murtas; G. P. Murtas; M. Pepe-Altarelli; S. J. Dorris; A. W. Halley; I. ten Have; I. G. Knowles; J. G. Lynch; W. T. Morton; V. O’Shea; C. Raine; P. Reeves; J. M. Scarr; K. Smith; M. G. Smith; A. S. Thompson; F. Thomson; S. Thorn; R. M. Turnbull; U. Becker; O. Braun; C. Geweniger; G. Graefe; P. Hanke; V. Hepp; E. E. Kluge; A. Putzer; B. Rensch; M. Schmidt; J. Sommer; H. Stenzel; K. Tittel; S. Werner; M. Wunsch; R. Beuselinck; David M Binnie; W. Cameron; D. J. Colling; Peter J Dornan; N P Konstantinidis; L. Moneta; A. Moutoussi; J. Nash; G. San Martin; J. K. Sedgbeer; A. M. Stacey; G. Dissertori; P. Girtler; E. Kneringer; D. Kuhn; G. Rudolph; C. K. Bowdery; T. J. Brodbeck; P. Colrain; G. Crawford; A. J. Finch; F. Foster; G. Hughes; Terence Sloan; E. P. Whelan; M. I. Williams; A. Galla; A. M. Greene; K. Kleinknecht; G. Quast; J. Raab; B. Renk; H.-G. Sander; R. Wanke; C. Zeitnitz; Jean-Jacques Aubert; A. M. Bencheikh; C. Bencheikh; C. Benchouk; A. Bonissent; G. Bujosa; D. Calvet; J. Carr; C. Diaconu; F. Etienne; M. Thulasidas; D. Nicod; P. Payre; D. Rousseau; M. Talby; I. Abt; R. Assmann; C. Bauer; W. Blum; D. Brown; H. Dietl; F. Dydak; G. Ganis; C. Gotzhein; K. Jakobs; H. Kroha; G. Lütjens; G. Lutz; W. Männer; H.-G. Moser; R. Richter; A. Rosado-Schlosser; S. Schael; R. Settles; H. Seywerd; U. Stierlin; R. St. Denis; G. Wolf; R. Alemany; J. Boucrot; O. Callot; A. Cordier; F. Courault; M. Davier; L. Duflot; J.-F. Grivaz; Ph Heusse; M. Jacquet; D. W. Kim; F. Le Diberder; J. Lefrançois; A.-M. Lutz; G. Musolino; I. Nikolic; H. J. Park; I. C. Park; M.-H. Schune; S. Simion; J.-J. Veillet; I. Videau; D. Abbaneo; P. Azzurri; G Batignani; G. Batignani; S. Bettarini; C. Bozzi; G. Calderini; M. Carpinelli; M. A. Ciocci; V. Ciulli; R. Dell’Orso; R. Fantechi; I. Ferrante; L. Foà; F. Forti; A. Giassi; M. A. Giorgi; A. Gregorio; F. Ligabue; A. Lusiani; P. S. Marrocchesi; A. Messineo; G. Rizzo; G. Sanguinetti; A. Sciabà; P. Spagnolo; J. Steinberger; R. Tenchini; G Triggiani; C. Vannini; P. G. Verdini; J. Walsh; A. P. Betteridge; G. A. Blair; L. M. Bryant; F. Cerutti; Y. Gao; M. G. Green; D. L. Johnson; T. Medcalf; L. M. Mir; P. Perrodo; J. A. Strong; V. Bertin; D. R. Botterill; R. W. Clifft; T. R. Edgecock; S. Haywood; M. Edwards; P. Maley; P. R. Norton; J. C. Thompson; B. Bloch-Devaux; P. Colas; H. Duarte; S. Emery; W. Kozanecki; E. Lançon; M. C. Lemaire; E. Locci; B. Marx; P. Perez; J F Renardy; A Roussarie; A. Roussarie; J Schwindling; D. Si Mohand; A. Trabelsi; B. Vallage; R. P. Johnson; H. Y. Kim; A. M. Litke; M. A. McNeil; G. Taylor; A. Beddall; C. N. Booth; R. Boswell; S. Cartwright; F. Combley; I. Dawson; A. Koksal; M. Letho; W. M. Newton; C. Rankin; L. F. Thompson; A. Böhrer; S. Brandt; G. Cowan; E. Feigl; C. Grupen; G. Lutters; J. Minguet-Rodriguez; F. Rivera; P. Saraiva; L. Smolik; F. Stephan; M. Apollonio; L. Bosisio; R. Della Marina

1995-01-01

381

On the deformed photon-added and photon-subtracted states  

NASA Astrophysics Data System (ADS)

In this paper, we introduce the deformed algebra whose number operator is expressed in terms of the product of the creation operator and annihilation operator. We give some examples for these kinds of deformed algebras. For Arik-Coon's q-oscillator algebra, we discuss, especially, the photon-added states and the photon-subtracted states and construct their associated generation functions.

Chung, Won Sang

2014-10-01

382

Notoph-Graviton-Photon Coupling  

E-print Network

In the sixties Ogievetskii and Polubarinov proposed the concept of a notoph, whose helicity properties are complementary to those of a photon. Later, Kalb and Ramond (and others) developed this theoretical concept. And, at the present times it is widely accepted. We analyze the quantum theory of antisymmetric tensor fields with taking into account mass dimensions of notoph and photon. It appears to be possible to describe both photon and notoph degrees of freedom on the basis of the modified Bargmann-Wigner formalism for the symmetric second-rank spinor. Next, we proceed to derive equations for the symmetric tensor of the second rank on the basis of the Bargmann-Wigner formalism in a straightforward way. The symmetric multispinor of the fourth rank is used. It is constructed out of the Dirac 4-spinors. Due to serious problems with the interpretation of the results obtained on using the standard procedure we generalize it and obtain the spin-2 relativistic equations, which are consistent with the general relativity. The importance of the 4-vector field (and its gauge part) is pointed out. Thus, we present the full theory which contains photon, notoph (the Kalb-Ramond field) and the graviton. The relations of this theory with the higher spin theories are established. In fact, we deduced the gravitational field equations from relativistic quantum mechanics. We estimate possible interactions, fermion-notoph, graviton-notoph, photon-notoph. PACS number: 03.65.Pm, 04.50.-h, 11.30.Cp

Valeriy V. Dvoeglazov

2013-08-22

383

Interfacing GHz-bandwidth heralded single photons with a room-temperature Raman quantum memory  

E-print Network

Photonics is a promising platform for quantum technologies. However, photon sources and two-photon gates currently only operate probabilistically. Large-scale photonic processing will therefore be impossible without a multiplexing strategy to actively select successful events. High time-bandwidth-product quantum memories - devices that store and retrieve single photons on-demand - provide an efficient remedy via active synchronisation. Here we interface a GHz-bandwidth heralded single-photon source and a room-temperature Raman memory with a time-bandwidth product exceeding 1000. We store heralded single photons and observe a clear influence of the input photon statistics on the retrieved light, which agrees with our theoretical model. The preservation of the stored field's statistics is limited by four-wave-mixing noise, which we identify as the key remaining challenge in the development of practical memories for scalable photonic information processing.

P. S. Michelberger; T. F. M. Champion; M. R. Sprague; K. T. Kaczmarek; M. Barbieri; X. M. Jin; D. G. England; W. S. Kolthammer; D. J. Saunders; J. Nunn; I. A. Walmsley

2014-05-06

384

Nuclear photonics  

SciTech Connect

With the planned new {gamma}-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 10{sup 13}{gamma}/s and a band width of {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -3}, a new era of {gamma} beams with energies up to 20MeV comes into operation, compared to the present world-leading HI{gamma}S facility at Duke University (USA) with 10{sup 8}{gamma}/s and {Delta}E{gamma}/E{gamma} Almost-Equal-To 3 Dot-Operator 10{sup -2}. In the long run even a seeded quantum FEL for {gamma} beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused {gamma} beams. Here we describe a new experiment at the {gamma} beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for {gamma} beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for {gamma} beams are being developed. Thus, we have to optimize the total system: the {gamma}-beam facility, the {gamma}-beam optics and {gamma} detectors. We can trade {gamma} intensity for band width, going down to {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -6} and address individual nuclear levels. The term 'nuclear photonics' stresses the importance of nuclear applications. We can address with {gamma}-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, {gamma} beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to {mu}m resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

Habs, D.; Guenther, M. M.; Jentschel, M.; Thirolf, P. G. [Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany); Max Planck Institut fuer Quantenoptik, D-85748 Garching (Germany); Institut Laue-Langevin, F-38042 Grenoble (Germany); Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany)

2012-07-09

385

Photon-photon scattering: a tutorial  

E-print Network

Long-established results for the low-energy photon-photon scattering, gamma gamma --> gamma gamma, have recently been questioned. We analyze that claim and demonstrate that it is inconsistent with experience. We demonstrate that the mistake originates from an erroneous manipulation of divergent integrals and discuss the connection with another recent claim about the Higgs decay into two photons. We show a simple way of correctly computing the low-energy gamma gamma scattering.

Liang, Yi

2011-01-01

386

Photon-photon scattering: a tutorial  

E-print Network

Long-established results for the low-energy photon-photon scattering, gamma gamma --> gamma gamma, have recently been questioned. We analyze that claim and demonstrate that it is inconsistent with experience. We demonstrate that the mistake originates from an erroneous manipulation of divergent integrals and discuss the connection with another recent claim about the Higgs decay into two photons. We show a simple way of correctly computing the low-energy gamma gamma scattering.

Yi Liang; Andrzej Czarnecki

2011-11-25

387

Learning Statistics By Doing Statistics  

NSDL National Science Digital Library

This article, created by Gary Smith of Pomona College, discusses a project-based approach to teaching statistics. The article focuses on the team aspect of learning, it introduces concepts such as: working with data, learning by doing, learning by writing, learning by speaking, and authentic assessment of material. An appendix contains a list of twenty projects that have been successfully assigned.

Smith, Gary

2009-02-02

388

Modern Statistical Methods for GLAST Event Analysis  

E-print Network

We describe a statistical reconstruction methodology for the GLAST LAT. The methodology incorporates in detail the statistics of the interactions of photons and charged particles with the tungsten layers in the LAT, and uses the scattering distributions to compute the full probability distribution over the energy and direction of the incident photons. It uses model selection methods to estimate the probabilities of the possible geometrical configurations of the particles produced in the detector, and numerical marginalization over the energy loss and scattering angles at each layer. Preliminary results show that it can improve on the tracker-only energy estimates for muons and electrons incident on the LAT.

Robin D. Morris; Johann Cohen-Tanugi

2007-03-28

389

Web Pages That Perform Statistical Calculations: Interactive Statistical Calculation Pages  

NSDL National Science Digital Library

John Pezullo, Associate Professor of Pharmacology and Biostatistics at Georgetown University, has helped compile this monstrous metasite of freely accessible multi-platform statistical software. With links to pages around the world, the table of contents includes access to calculators, plotters, random number generators, and programs that perform literally hundreds of calculations. Hosted by America Online, the site also includes links to online statistics books, tutorials, and downloadable software. This is a virtual treasure trove of statistical calculation pages for mathematicians and statisticians.

390

VOLUME 88, NUMBER 7 P H Y S I C A L R E V I E W L E T T E R S 18 FEBRUARY 2002 Teleportation of a VacuumOne-Photon Qubit  

E-print Network

VOLUME 88, NUMBER 7 P H Y S I C A L R E V I E W L E T T E R S 18 FEBRUARY 2002 Teleportation 2002) We report the experimental realization of teleporting a one-particle entangled qubit. The qubit) 409, 46 (2001)]. An unprecedented large value of the teleportation "fidelity" has been attained: F 95

Roma "La Sapienza", Università di

391

Photonic Molecules and Spectral Engineering  

E-print Network

This chapter reviews the fundamental optical properties and applications of photonic molecules (PMs) – photonic structures formed by electromagnetic coupling of two or more optical microcavities (photonic atoms). Controllable ...

Boriskina, Svetlana V.

2010-01-01

392

State-dependent photon blockade via quantum-reservoir engineering  

NASA Astrophysics Data System (ADS)

An arbitrary initial state of an optical or microwave field in a lossy driven nonlinear cavity can be changed into a partially incoherent superposition of only the vacuum and the single-photon states. This effect is known as single-photon blockade, which is usually analyzed for a Kerr-type nonlinear cavity parametrically driven by a single-photon process assuming single-photon loss mechanisms. We study photon blockade engineering via a nonlinear reservoir, i.e., a quantum reservoir, where only two-photon absorption is allowed. Namely, we analyze a lossy nonlinear cavity parametrically driven by a two-photon process and allowing two-photon loss mechanisms, as described by the master equation derived for a two-photon absorbing reservoir. The nonlinear cavity engineering can be realized by a linear cavity with a tunable two-level system via the Jaynes-Cummings interaction in the dispersive limit. We show that by tuning properly the frequencies of the driving field and the two-level system, the steady state of the cavity field can be the single-photon Fock state or a partially incoherent superposition of several Fock states with photon numbers, e.g., (0,2), (1,3), (0,1,2), or (0,2,4). At the right (now fixed) frequencies, we observe that an arbitrary initial coherent or incoherent superposition of Fock states with an even (odd) number of photons is changed into a partially incoherent superposition of a few Fock states of the same photon-number parity. We find analytically approximate formulas for these two kinds of solutions for several differently tuned systems. A general solution for an arbitrary initial state is a weighted mixture of the above two solutions with even and odd photon numbers, where the weights are given by the probabilities of measuring the even and odd numbers of photons of the initial cavity field, respectively. This can be interpreted as two separate evolution-dissipation channels for even and odd-number states. Thus, in contrast to the standard predictions of photon blockade, we prove that the steady state of the cavity field, in the engineered photon blockade, can depend on its initial state. To make our results more explicit, we analyze photon blockades for some initial infinite-dimensional quantum and classical states via the Wigner and photon-number distributions.

Miranowicz, Adam; Bajer, Ji?í; Paprzycka, Ma?gorzata; Liu, Yu-xi; Zagoskin, Alexandre M.; Nori, Franco

2014-09-01

393

Teleporting photonic qudits using multimode quantum scissors.  

PubMed

Teleportation plays an important role in the communication of quantum information between the nodes of a quantum network and is viewed as an essential ingredient for long-distance Quantum Cryptography. We describe a method to teleport the quantum information carried by a photon in a superposition of a number d of light modes (a "qudit") by the help of d additional photons based on transcription. A qudit encoded into a single excitation of d light modes (in our case Laguerre-Gauss modes which carry orbital angular momentum) is transcribed to d single-rail photonic qubits, which are spatially separated. Each single-rail qubit consists of a superposition of vacuum and a single photon in each one of the modes. After successful teleportation of each of the d single-rail qubits by means of "quantum scissors" they are converted back into a qudit carried by a single photon which completes the teleportation scheme. PMID:24352610

Goyal, Sandeep K; Konrad, Thomas

2013-01-01

394

Statistical restoration for robust and secure steganography  

Microsoft Academic Search

We investigate data hiding techniques that attempt to defeat steganalysis by restoring the statistics of the composite image to resemble that of the cover. The approach is to reserve a number of host symbols for statistical restoration: host statistics perturbed by data embedding are restored by suitably modifying the symbols from the reserved set. While statistical restoration has broad ap-

Kaushal Solanki; Kenneth Sullivan; Upamanyu Madhow; B. S. Manjunath; Shivkumar Chandrasekaran

2005-01-01

395

A study of photon interaction parameters in lung tissue substitutes  

PubMed Central

The study of photon interaction with different composite materials has become a topic of prime importance for radiation physicists. Some parameters of dosimetric interest are the mass attenuation coefficient, effective atomic number, and electron density; these help in the basic understanding of photon interactions with composite materials. The photon interaction parameters such as mass attenuation coefficient (?/?), effective atomic number (Zeff), and effective electron density (Nel) must be identical for the phantom material and their tissue. In the present study, we have evaluated the photon interaction parameters such as (?/?), Zeff and Nel of 13 lung tissue substitutes. The variations of these parameters of lung tissue substitutes with photon energy are graphically represented. The photon interaction parameters of lung tissue substitutes are compared with that of lung tissue. The variation of photon interaction parameters of the studied lung tissue substitutes is similar that of the lung. Logically, it can be shown that Alderson lung is good substitute for lung than the other substitutes. PMID:24872609

Manjunatha, H. C.

2014-01-01

396

Photonic crystals and related photonic nanodevices  

Microsoft Academic Search

This talk presents some photonic crystal (PC) and quasiperiodic photonic crystal (QPC) microlasers based on InP materials, and the other an potential application of PC line defect waveguide for an optical group delay device. The PC laser exhibits a fast spontaneous emission decay even far below threshold, which is explained by Purcell effect. The QPC laser shows unique lasing characteristics

Toshihiko Baba

2004-01-01

397

Spike statistics  

E-print Network

In this paper we explore stochastical and statistical properties of so-called recurring spike induced Kasner sequences. Such sequences arise in recurring spike formation, which is needed together with the more familiar BKL scenario to yield a complete description of generic spacelike singularities. In particular we derive a probability distribution for recurring spike induced Kasner sequences, complementing similar available BKL results, which makes comparisons possible. As examples of applications, we derive results for so-called large and small curvature phases and the Hubble-normalized Weyl scalar.

J. Mark Heinzle; Claes Uggla

2012-12-21

398

SOCR: Statistics Online Computational Resource  

ERIC Educational Resources Information Center

The need for hands-on computer laboratory experience in undergraduate and graduate statistics education has been firmly established in the past decade. As a result a number of attempts have been undertaken to develop novel approaches for problem-driven statistical thinking, data analysis and result interpretation. In this paper we describe an…

Dinov, Ivo D.

2006-01-01

399

Four Faculty Positions Applied Statistics & Computational Statistics  

E-print Network

Four Faculty Positions Applied Statistics & Computational Statistics The Department of Statistics at the Assistant Professor rank. Two positions are open in the area of Applied Statistics, with a focus on the development of statistical methodology and statistical consulting. The other two positions are open

Shepp, Larry

400

Number Guessing  

ERIC Educational Resources Information Center

It is instructive and interesting to find hidden numbers by using different positional numeration systems. Most of the present guessing techniques use the binary system expressed as less-than, greater-than or present-absent type information. This article describes how, by employing four cards having integers 1-64 written in different colours, one…

Sezin, Fatin

2009-01-01

401

Numbers, Please!  

ERIC Educational Resources Information Center

What topic would you choose if you had the luxury of writing forever? In this article, John Thelin provides his response: He would opt to write about the history of higher education in a way that relies on quantitative data. "Numbers, please!" is his research request in taking on a longitudinal study of colleges and universities over…

Thelin, John R.

2013-01-01

402

Three-Dimensional Statistics of Radio Polarimetry  

E-print Network

The measurement of radio polarization may be regarded as a three-dimensional statistical problem because the large photon densities at radio wavelengths allow the simultaneous detection of the three Stokes parameters which completely describe the radiation's polarization. The statistical nature of the problem arises from the fluctuating instrumental noise, and possibly from fluctuations in the radiation's polarization. A statistical model is used to derive the general, three-dimensional statistics that govern radio polarization measurements. The statistics are derived for specific cases of source-intrinsic polarization, with an emphasis on the orthogonal polarization modes in pulsar radio emission. The statistics are similar to those commonly found in other fields of the physical, biological, and Earth sciences. Given the highly variable linear and circular polarization of pulsar radio emission, an understanding of the three-dimensional statistics may be an essential prequisite to a thorough interpretation of pulsar polarization data.

Mark M. McKinnon

2003-06-03

403

Photon transitions in Upsilon(2S) and Upsilon(3S) decays  

E-print Network

We have studied the inclusive photon spectra in Y(2S) and Y(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates and photon...

Besson, David Zeke

2005-01-01

404

Species number with confidence  

NASA Astrophysics Data System (ADS)

Benthic sampling by J. Frederick Grassle and Nancy J. Maciolek during the 1980s contributed to a recognition of the enormous diversity of biota in the deep sea. The problem of predicting on the basis of such sampling, the number of species in a community is a classical one in statistical ecology. Here, we show how to construct a lower prediction bound on species number using the sequential broken-stick model of relative abundances. We illustrate the method using some data from Grassle and Maciolek's original sampling effort.

Smith, Woollcott K.; Solow, Andrew R.; Maciolek, Nancy J.

2009-09-01

405

Direct photon interferometry  

E-print Network

We consider recent developments in the theory of the two-photon interferometry in ultrarelativistic heavy ion collisions with emphasis on the difference between photon and hadron interferometry. We review the available experimental results and discuss possibilities of measurement of the photon Bose-Einstein correlations in ongoing and future experiments.

D. Peressounko

2005-12-08

406

Photon Physics in ALICE  

E-print Network

We give an overview of photon physics which will be studied by the ALICE experiment in proton-proton and heavy ion collisions at LHC. We compare properties of ALICE photon detectors and estimate their ability to measure neutral meson and direct photon spectra as well as gamma-hadron and gamma-jet correlations in pp and Pb+Pb collisions.

D. Peressounko; Y. Kharlov; for the ALICE collaboration

2009-07-16

407

Physics with polarized photons  

SciTech Connect

The role that polarization can play in the interaction of real and virtual photons with nuclear matter is considered. Linear, circular, and elliptical polarization are considered. Photodisintegration of the deuteron with linearly polarized photons is then examined, followed by use of circularly polarized photons with a polarized target. 30 refs., 4 figs. (LEW)

Matone, G.

1985-10-01

408

Hierarchy of feasible nonclassicality criteria for sources of photons  

NASA Astrophysics Data System (ADS)

We present an ab-initio derivation of a hierarchy of efficient nonclassicality criteria for sources of photons. The operational criteria are explicitly proposed for the linear optical multiport and feasible multiplexed single-photon detectors. The lowest criterion is equivalent to the frequently used g(2)(0) autocorrelation measurement testing the anticorrelation effect of photons. We also derive a hierarchy of criteria for the detectors capable to at least partially estimate photon-number distribution. We prove the usefulness of both hierarchies to detect the nonclassical states from the noisy multimode single-photon sources and the nonclassical states from the multiphoton sources.

Filip, Radim; Lachman, Lukáš

2013-10-01

409

First Results from Photon Multiplicity Detector at RHIC  

E-print Network

We present the first measurement of multiplicity and pseudorapidity distributions of photons in the pseudorapidity region 2.3 < eta < 3.7 for different centralities in Au + Au collisions at sqrt{s_NN} = 62.4 GeV. The pseudorapidity distribution of photons, dominated by neutral pion decays, has been compared to those of identified charged pions, photons, and inclusive charged particles from heavy ion and nucleon-nucleon collisions at various energies. Scaling of photon yield with number of participating nucleons and limiting fragmentation scenario for inclusive photon production has been studied.

Bedangadas Mohanty

2005-09-30

410

Heavy flavor production from photons and hadrons  

SciTech Connect

The present state of the production and observation of hadrons containing heavy quarks or antiquarks as valence constituents, in reactions initiated by real and (space-like) virtual photon or by hadron beams is discussed. Heavy flavor production in e/sup +/e/sup -/ annihilation, which is well covered in a number of recent review papers is not discussed, and similarly, neutrino production is omitted due to the different (flavor-changing) mechanisms that are involved in those reactions. Heavy flavors from spacelike photons, heavy flavors from real photons, and heavy flavors from hadron-hadron collisions are discussed. (WHK)

Heusch, C.A.

1982-01-01

411

Dow Corning photonics: the silicon advantage in automotive photonics  

NASA Astrophysics Data System (ADS)

The Automotive Market offers several opportunities for Dow Corning to leverage the power of silicon-based materials. Dow Corning Photonics Solutions has a number of developments that may be attractive for the emergent photonics needs in automobiles, building on 40 years of experience as a leading Automotive supplier with a strong foundation of expertise and an extensive product offering- from encapsulents and highly reliable resins, adhesives, insulating materials and other products, ensuring that the advantage of silicones are already well-embedded in Automotive systems, modules and components. The recent development of LED encapsulants of exceptional clarity and stability has extended the potential for Dow Corning"s strength in Photonics to be deployed "in-car". Demonstration of board-level and back-plane solutions utilising siloxane waveguide technology offers new opportunities for systems designers to integrate optical components at low cost on diverse substrates. Coupled with work on simple waveguide technology for sensors and data communications applications this suite of materials and technology offerings is very potent in this sector. The harsh environment under hood and the very extreme thermal range that materials must sustain in vehicles due to both their engine and the climate is an applications specification that defines the siloxane advantage. For these passive optics applications the siloxanes very high clarity at the data-communications wavelengths coupled with extraordinary stability offers significant design advantage. The future development of Head-Up-Displays for instrumentation and data display will offer yet more opportunities to the siloxanes in Automotive Photonics.

Clapp, Terry V.; Paquet, Rene; Norris, Ann; Pettersen, Babette

2005-02-01

412

Occupational Employment Statistics  

NSDL National Science Digital Library

US occupations are featured in this information-rich resources from the Bureau of Labor Statistics. The 1996 Occupational Employment Statistics Survey differs from previous surveys in that it includes wage data by occupation for the first time. The site contains a description of the survey and complete national and state data for 760 occupations in seven major areas. Included are occupation title, number of employees, hourly mean and median wage, and an OES code number that provides information about the occupation and its employment distribution by wage range where surveyed (distribution is for the national survey only). An occupational search engine is forthcoming. The site also contains information about previous OES surveys back to 1988.

413

Photon Localization and Dicke Superradiance in Atomic Gases  

NASA Astrophysics Data System (ADS)

Photon propagation in a gas of N atoms is studied using an effective Hamiltonian describing photon-mediated atomic dipolar interactions. The density P(?) of photon escape rates is determined from the spectrum of the N×N random matrix ?ij=sin?(xij)/xij, where xij is the dimensionless random distance between any two atoms. Varying disorder and system size, a scaling behavior is observed for the escape rates. It is explained using microscopic calculations and a stochastic model which emphasizes the role of cooperative effects in photon localization and provides an interesting relation with statistical properties of “small world networks.”

Akkermans, E.; Gero, A.; Kaiser, R.

2008-09-01

414

Topological Invariants in Point Group Symmetric Photonic Topological Insulators  

E-print Network

We proposed a group-theory method to calculate topological invariant in bi-isotropic photonic crystals invariant under crystallographic point group symmetries. Spin Chern number has been evaluated by the eigenvalues of rotation operators at high symmetry k-points after the pseudo-spin polarized fields are retrieved. Topological characters of photonic edge states and photonic band gaps can be well predicted by total spin Chern number. Nontrivial phase transition is found in large magnetoelectric coupling due to the jump of total spin Chern number. Light transport is also issued at the {\\epsilon}/{\\mu} mismatching boundary between air and the bi-isotropic photonic crystal. This finding presents the relationship between group symmetry and photonic topological systems, which enables the design of photonic nontrivial states in a rational manner.

Chen, Xiao-Dong; Chen, Wen-Jie; Wang, Jia-Rong; Dong, Jian-Wen

2014-01-01

415

Quantum target detection using entangled photons  

E-print Network

We investigate performances of pure continuous variable states in discriminating thermal and identity channels by comparing their M-copy error probability bounds. This offers us a simplified mathematical analysis for quantum target detection with slightly modified features: the object -- if it is present -- perfectly reflects the signal beam irradiating it, while thermal noise photons are returned to the receiver in its absence. This model facilitates us to obtain analytic results on error-probability bounds i.e., the quantum Chernoff bound and the lower bound constructed from the Bhattacharya bound on M-copy discrimination error-probabilities of some important quantum states, like photon number states, N00N states, coherent states and the entangled photons obtained from spontaneous parametric down conversion (SPDC). Comparing the $M$-copy error-bounds, we identify that N00N states indeed offer enhanced sensitivity than the photon number state system, when average signal photon number is small compared to the thermal noise level. However, in the high signal-to-noise scenario, N00N states fail to be advantageous than the photon number states. Entangled SPDC photon pairs too outperform conventional coherent state system in the low signal-to-noise case. On the other hand, conventional coherent state system surpasses the performance sensitivity offered by entangled photon pair, when the signal intensity is much above that of thermal noise. We find an analogous performance regime in the lossy target detection (where the target is modeled as a weakly reflecting object) in a high signal-to-noise scenario.

A. R. Usha Devi; A. K. Rajagopal

2009-03-23

416

Measuring topological invariants in photonic systems  

E-print Network

Motivated by the recent theoretical and experimental progress in implementing topological orders with photons, we analyze photonic systems with different topologies and present a scheme to probe their topological features. Specifically, we propose a scheme to modify the boundary phases to manipulate edge state dynamics. Such a scheme allows one to measure the winding number of the edge states. Furthermore, we discuss the effect of loss and disorder on the validity of our approach.

Mohammad Hafezi

2013-10-29

417

An introduction to Photonic Crystals  

E-print Network

An introduction to Photonic Crystals Optics and Photonics Spring 2012 Libo Weng #12;Outline · Definition · Butterfly ­ Photonic crystals in nature · Comparison between semiconductor(electrons) and photonic crystal(photons) · Physics Origin of Band Gap · Defects in photonic crystals and Applications

Palffy-Muhoray, Peter

418

Optomechanical photon shuttling between photonic cavities  

E-print Network

Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave-mixing between photons and phonons and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong nonlocal effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a novel multi-cavity optomechanical device: a "photon see-saw", in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of the see-saw, are modulated anti-symmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation which strongly modulates the inter-cavity coupling and shuttles photons to the other empty cavity during every oscillation cycle in a well regulated fashion.

Huan Li; Mo Li

2014-09-03

419

Generation of a highly phase sensitive polarization squeezed N-photon state by collinear parametric downconversion and coherent photon subtraction  

E-print Network

It is shown that a highly phase sensitive polarization squeezed (2n-1)-photon state can be generated by subtracting a diagonally polarized photon from the 2n photon component generated in collinear type II downconversion. This polarization wedge state has the interesting property that its photon number distribution in the horizontal and vertical polarizations remains sharply defined for phase shifts of up to 1/n between the circularly polarized components. Phase shifts at the Heisenberg limit are therefore observed as nearly deterministic transfers of a single photon between the horizontal and vertical polarization components.

Holger F. Hofmann

2005-10-02

420

[Estimated numbers of visceral mycoses in cases of leukemia and MDS in Japan : analysis of data from the Annual of Pathological Autopsy Cases and the vital statistics published by Ministry of health, labour and welfare in Japan].  

PubMed

Our analysis reported here, is the first one in the world to make a nationwide-level estimate on numbers of visceral mycoses in case of leukemia and myelodysplastic syndrome (MDS)in Japan. The data on visceral mycoses in cases reported in the" Annual of the Pathological Autopsy Cases in Japan" published by the Japanese society of pathology in 2002 and 2006, and the data in the vital statics in Japan published by Ministry of health, labour and welfare were analyzed epidemiologically. The estimated numbers of visceral mycoses were 2,250 out of the estimated total death 8,976 in 2001, and 2290 out of 9,805 in 2005, respectively, in cases of leukemia and MDS in Japan. Furthermore, the estimated severe cases that we thought direct cause of death were 1,454 in 2001, and 1,464 in 2005, respectively. In the severe cases, the most causative agents were Aspergillus. The estimated numbers of Candida and Zygomycetes were interestingly almost same in the severe cases, but the lethal rate in Zygomycetes was about 60-80 % , almost twice as that in Candida. We think it is imperative to continuously survey and watch these rates towards the future. PMID:22467132

Togano, Tomiteru; Shibuya, Kazutoshi; Kume, Hikaru

2012-01-01

421

Photon wave function  

E-print Network

Photon wave function is a controversial concept. Controversies stem from the fact that photon wave functions can not have all the properties of the Schroedinger wave functions of nonrelativistic wave mechanics. Insistence on those properties that, owing to peculiarities of photon dynamics, cannot be rendered, led some physicists to the extreme opinion that the photon wave function does not exist. I reject such a fundamentalist point of view in favor of a more pragmatic approach. In my view, the photon wave function exists as long as it can be precisely defined and made useful.

Iwo Bialynicki-Birula

2005-08-26

422

Photon: history, mass, charge  

E-print Network

The talk consists of three parts. ``History'' briefly describes the emergence and evolution of the concept of photon during the first two decades of the 20th century. ``Mass'' gives a short review of the literature on the upper limit of the photon's mass. ``Charge'' is a critical discussion of the existing interpretation of searches for photon charge. Schemes, in which all photons are charged, are grossly inconsistent. A model with three kinds of photons (positive, negative and neutral) seems at first sight to be more consistent, but turns out to have its own serious problems.

L. B. Okun

2006-02-03

423

Digest of Education Statistics 2000  

NSDL National Science Digital Library

In late January, the National Center for Education Statistics (NCES) released this new publication. Published January 26th 2001, the Digest of Education Statistics, 2000 "provides a compilation of statistical information covering the broad field of education from prekindergarten through graduate school." Data in the digest cover "the number of schools and colleges; teachers; enrollments; graduates; educational attainment; finances; federal funds for education; employment and income of graduates; libraries; technology; and international comparisons." (The Digest of Education Statistics, 1999 was featured in the April 4th, 2000 Scout Report for the Social Sciences.) The publication is in .pdf format and may be downloaded in its entirety or in selected chapters.

2001-01-01

424

Scalable spatial superresolution using entangled photons.  

PubMed

N00N states-maximally path-entangled states of N photons-exhibit spatial interference patterns sharper than any classical interference pattern. This is known as superresolution. However, even given perfectly efficient number-resolving detectors, the detection efficiency of all previous measurements of such interference would decrease exponentially with the number of photons in the N00N state, often leading to the conclusion that N00N states are unsuitable for spatial measurements. A technique known as the "optical centroid measurement" has been proposed to solve this and has been experimentally verified for photon pairs; here we present the first extension beyond two photons, measuring the superresolution fringes of two-, three-, and four-photon N00N states. Moreover, we compare the N00N-state interference to the corresponding classical superresolution interference. Although both provide the same increase in spatial frequency, the visibility of the classical fringes decreases exponentially with the number of detected photons. Our work represents an essential step forward for quantum-enhanced measurements, overcoming what was believed to be a fundamental challenge to quantum metrology. PMID:24949765

Rozema, Lee A; Bateman, James D; Mahler, Dylan H; Okamoto, Ryo; Feizpour, Amir; Hayat, Alex; Steinberg, Aephraim M

2014-06-01

425

Localized photonic modes in photonic crystal heterostructures  

NASA Astrophysics Data System (ADS)

In this work, interface modes of two-dimensional photonic crystal heterostructures have been investigated by usage of the supercell method. The photonic crystal heterostructure is made of two photonic crystals with square symmetry in which one of them is composed of circular dielectric rods in air background and the other one is constructed by drilled square holes in dielectric. It is shown that using of a proper supercell plays an important role in obtaining the correct interface modes. We have also showed that the guided interface modes and single mode which is different from those reported in some published works are nearly dispersionless.

Mehrabi, Mohsen; Soltani-Vala, Ali; Barvestani, Jamal

2011-11-01

426

Problems on Non-Equilibrium Statistical Physics  

E-print Network

Four problems in non-equilibrium statistical physics are investigated: 1. The thermodynamics of single-photon gas; 2. Energy of the ground state in Multi-electron atoms; 3. Energy state of the H2 molecule; and 4. The Condensation behavior in N...

Kim, Moochan

2011-08-08

427

Statistical Reconstruction in CT Jeffrey A. Fessler  

E-print Network

, focal spot size, ... improved spatial resolution? detector spectral response (e.g., photon-counting1 Statistical Reconstruction in CT Jeffrey A. Fessler EECS Department University of Michigan SPIE · Meng Wu GE collaborators · Jiang Hsieh · Jean-Baptiste Thibault · Bruno De Man CT collaborators · Mitch

Fessler, Jeffrey A.

428

Bose-Einstein condensation of photons in a 'white-wall' photon box  

NASA Astrophysics Data System (ADS)

Bose-Einstein condensation, the macroscopic ground state occupation of a system of bosonic particles below a critical temperature, has been observed in cold atomic gases and solid-state physics quasiparticles. In contrast, photons do not show this phase transition usually, because in Planck's blackbody radiation the particle number is not conserved and at low temperature the photons disappear in the walls of the system. Here we report on the realization of a photon Bose-Einstein condensate in a dye-filled optical microcavity, which acts as a "white-wall" photon box. The cavity mirrors provide a trapping potential and a non-vanishing effective photon mass, making the system formally equivalent to a two-dimensional gas of trapped massive bosons. Thermalization of the photon gas is reached in a number conserving way by multiple scattering off the dye molecules. Signatures for a BEC upon increased photon density are: a spectral distribution that shows Bose-Einstein distributed photon energies with a macroscopically populated peak on top of a broad thermal wing, the observed threshold of the phase transition showing the predicted absolute value and scaling with resonator geometry, and condensation appearing at the trap centre even for a spatially displaced pump spot.

Klärs, Jan; Schmitt, Julian; Vewinger, Frank; Weitz, Martin

2011-01-01

429

Means and method for calibrating a photon detector utilizing electron-photon coincidence  

NASA Technical Reports Server (NTRS)

An arrangement for calibrating a photon detector particularly applicable for the ultraviolet and vacuum ultraviolet regions is based on electron photon coincidence utilizing crossed electron beam atom beam collisions. Atoms are excited by electrons which lose a known amount of energy and scatter with a known remaining energy, while the excited atoms emit photons of known radiation. Electrons of the known remaining energy are separated from other electrons and are counted. Photons emitted in a direction related to the particular direction of scattered electrons are detected to serve as a standard. Each of the electrons is used to initiate the measurements of a time interval which terminates with the arrival of a photon exciting the photon detector. Only the number of time intervals related to the coincidence correlation and of electrons scattered in the particular direction with the known remaining energy and photons of a particular radiation level emitted due to the collisions of such scattered electrons are counted. The detector calibration is related to the number of counted electrons and photons.

Srivastava, S. K. (inventor)

1984-01-01

430

[Statistical surveys].  

PubMed

Data are included on natural increase in Czechoslovakia, 1972-1981 and 1976-1982; number of women aged 15-29, 1979-1981; nuptiality, divorce rate, abortions, and live births and fertility, 1979-1981; population over age 60, 1979-1981; mortality, life expectancy, and infant mortality, 1979-1981; causes of death, 1980-1981; internal and international migration, 1979-1981; and sex ratio, 1979-1981. PMID:12158179

1982-01-01

431

The Photon Underproduction Crisis  

E-print Network

We examine the statistics of the low-redshift Lyman-alpha forest from smoothed particle hydrodynamic simulations in light of recent improvements in the estimated evolution of the cosmic ultraviolet background (UVB) and recent observations from the Cosmic Origins Spectrograph (COS). We find that the value of the metagalactic photoionization rate required by our simulations to match the observed properties of the low-redshift Lyman-alpha forest is a factor of 5 larger than the value predicted by state-of-the art models for the evolution of this quantity. This mismatch results in the mean flux decrement of the Lyman-alpha forest being underpredicted by at least a factor of 2 (a 10-sigma discrepancy with observations) and a column density distribution of Lyman-alpha forest absorbers systematically and significantly elevated compared to observations over nearly two decades in column density. We examine potential resolutions to this mismatch and find that either conventional sources of ionizing photons (galaxies an...

Kollmeier, Juna A; Oppenheimer, Benjamin D; Haardt, Francesco; Katz, Neal; Davé, Romeel A; Fardal, Mark; Madau, Piero; Danforth, Charles; Ford, Amanda B; Peeples, Molly S; McEwen, Joseph

2014-01-01

432

Single Photon Transistor Mediated by Inter-State Rydberg Interaction  

E-print Network

We report on the realization of an all-optical transistor by mapping gate and source photons into strongly interacting Rydberg excitations with different principal quantum numbers in an ultracold atomic ensemble. We obtain a record switch contrast of 40 % for a coherent gate input with mean photon number one and demonstrate attenuation of source transmission by over 10 photons with a single gate photon. We use our optical transistor to demonstrate the nondestructive detection of a single Rydberg atom with a fidelity of 0.72(4).

Hannes Gorniaczyk; Christoph Tresp; Johannes Schmidt; Helmut Fedder; Sebastian Hofferberth

2014-04-10

433

Statistical Digest No. 70 Fishery Statistics of  

E-print Network

Statistical Digest No. 70 Statistics of the United States 1976 Washington National Marine Fisheries Service #12;#12;Statistical Digest No. 70 Fishery Statistics of the United States 1976 Prepared by: Resource Statistics Division Joseph Pileggi, Chief B.G. Thompson, Assistant Chief

434

Investigating the Randomness of Numbers  

ERIC Educational Resources Information Center

The use of random numbers is pervasive in today's world. Random numbers have practical applications in such far-flung arenas as computer simulations, cryptography, gambling, the legal system, statistical sampling, and even the war on terrorism. Evaluating the randomness of extremely large samples is a complex, intricate process. However, the…

Pendleton, Kenn L.

2009-01-01

435

The Glasma, Photons and the Implications of Anisotropy  

E-print Network

We introduce distribution functions for quarks and gluons in the Glasma and discuss how they satisfy various relationships of statistical physics. We use these distributions to compute photon production in the early stages of heavy ion collisions. Photon rates satisfy geometric scaling, that is, the emission rate per unit area scales as a function of the saturation momenta divided by the transverse momentum of the photon. Photon distributions from the Glasma are steeper than those computed in the Thermalized Quark Gluon Plasma (TQGP). Both the delayed equilibration of the Glasma and a possible anisotropy in the pressure lead to slower expansion and mean times of photon emission of fixed energy are increased. This delayed emission might allow for larger photon elliptic flow.

Larry McLerran; Bjoern Schenke

2014-03-28

436

The Glasma, Photons and the Implications of Anisotropy  

E-print Network

We introduce distribution functions for quarks and gluons in the Glasma and discuss how they satisfy various relationships of statistical physics. We use these distributions to compute photon production in the early stages of heavy ion collisions. Photon rates satisfy geometric scaling, that is, the emission rate per unit area scales as a function of the saturation momenta divided by the transverse momentum of the photon. Photon distributions from the Glasma are steeper than those computed in the Thermalized Quark Gluon Plasma (TQGP). Both the delayed equilibration of the Glasma and a possible anisotropy in the pressure lead to slower expansion and mean times of photon emission of fixed energy are increased. This delayed emission might allow for larger photon elliptic flow.

McLerran, Larry

2014-01-01

437

Statistical simulation of multiple Compton backscattering process  

NASA Astrophysics Data System (ADS)

A number of laboratories are currently developing monochromatic sources of X-rays and gamma quanta based on the Compton backscattering (CBS) of laser photons by relativistic electrons. Modern technologies are capable of providing a concentration of electrons and photons in the interaction point such that each primary electron can emit several hard photons. In contrast to the well-known nonlinear CBS process, in which an initial electron "absorbs" a few laser photons and emits a single hard one, the above-mentioned process can be called a multiple CBS process and is characterized by a mean number of emitted photons. The present paper is devoted to simulating the parameters of a beam of back scattered quanta based on the Monte Carlo technique. It is shown that, even in the case of strong collimation of a resulting photon beam, the radiation monochromaticity may deteriorate because of the contribution coming from the multiple photon emission, which is something that must be considered while designing new CBS sources.

Potylitsyn, A. P.; Kolchuzhkin, A. M.

2014-09-01

438

Photonic Doppler Velocimetry Multiplexing Techniques: Evaluation of Photonic Techniques  

SciTech Connect

This poster reports progress related to photonic technologies. Specifically, the authors developed diagnostic system architecture for a Multiplexed Photonic Doppler Velocimetry (MPDV) that incorporates frequency and time-division multiplexing into existing PDV methodology to provide increased channel count. Current MPDV design increases number of data records per digitizer channel 8x, and also operates as a laser-safe (Class 3a) system. Further, they applied heterodyne interferometry to allow for direction-of-travel determination and enable high-velocity measurements (>10 km/s) via optical downshifting. They also leveraged commercially available, inexpensive and robust components originally developed for telecom applications. Proposed MPDV architectures employ only commercially available, fiber-coupled hardware.

Edward Daykin

2012-05-24

439

Two-photon imaging and spectroscopy of fresh human colon biopsies  

NASA Astrophysics Data System (ADS)

Two-photon fluorescence (TPEF) microscopy is a powerful tool to image human tissues up to 200 microns depth without any exogenously added probe. TPEF can take advantage of the autofluorescence of molecules intrinsically contained in a biological tissue, as such NADH, elastin, collagen, and flavins. Two-photon microscopy has been already successfully used to image several types of tissues, including skin, muscles, tendons, bladder. Nevertheless, its usefulness in imaging colon tissue has not been deeply investigated yet. In this work we have used combined two-photon excited fluorescence (TPEF), second harmonic generation microscopy (SHG), fluorescence lifetime imaging microscopy (FLIM), and multispectral two-photon emission detection (MTPE) to investigate different kinds of human ex-vivo fresh biopsies of colon. Morphological and spectroscopic analyses allowed to characterize both healthy mucosa, polyp, and colon samples in a good agreement with common routine histology. Even if further analysis, as well as a more significant statistics on a large number of samples would be helpful to discriminate between low, mild, and high grade cancer, our method is a promising tool to be used as diagnostic confirmation of histological results, as well as a diagnostic tool in a multiphoton endoscope or colonoscope to be used in in-vivo imaging applications.

Cicchi, R.; Sturiale, A.; Nesi, G.; Tonelli, F.; Pavone, F. S.

2012-03-01

440

Photon counting processor for laser velocimetry  

NASA Technical Reports Server (NTRS)

In some of the more difficult applications of laser Doppler velocimetry such as in combustion research, transonic flow, transverse wind, and others, the optical signals are too small for classical detection methods. This paper summarizes the theory, experimental prototype hardware, and test results for a new type of high-speed photon-correlation signal processor which is being developed for weak laser velocimeter signals and other photon-resolved signals. The new system may also be considered to be a statistical digital frequency discriminator. It uses full multiplication with 10-nsec delay time and has the potential for extension to the measurement of the velocity correlations and spectra.

Mayo, W. T., Jr.

1977-01-01

441

Maximum-likelihood reconstruction for single-photon emission computedtomography  

Microsoft Academic Search

A mathematical model is formulated for a gamma camera used to observe single-photon emissions from multiple view angles. The model accounts for the statistics of radioactive decays, nonuniform attenuation, and a depth-dependent point-spread function. The maximum-likelihood method of statistics is used with the model to derive an algorithm for estimating the distribution of radioactivity.

Michael I. Miller; T. R. Miller; D. L. Snyder

1985-01-01

442

Single-photon generation with InAs quantum dots Charles Santori1,2,4  

E-print Network

pulses, for which the photon number follows a Poisson distribution. Much progress has been made recently towards such devices, especially in suppressing the probability of emitting two photons in the same pulse

Vuckovic, Jelena

443

A square root analog to digital converter to optimally convert photonic signals for computed tomography  

E-print Network

The arrival of photons at a given location is a Poisson process with an associated shot noise which rises with the square root of the number of photons received. An analog-to-digital converter (ADC) with a square root ...

Bieniosek, Matthew (Matthew F.)

2010-01-01

444

A High Speed, Post-Processing Free, Quantum Random Number Generator  

Microsoft Academic Search

A quantum random number generator (QRNG) based on gated single photon\\u000adetection of an InGaAs photodiode at GHz frequency is demonstrated. Owing to\\u000athe extremely long coherence time of each photon, each photons' wavefuntion\\u000aextends over many gating cycles of the photodiode. The collapse of the photon\\u000awavefunction on random gating cycles as well as photon random arrival time\\u000adetection

J. F. Dynes; Z. L. Yuan; A. W. Sharpe; A. J. Shields

2008-01-01

445

Stupid statistics!  

PubMed

The method of least squares is probably the most powerful data analysis tool available to scientists. Toward a fuller appreciation of that power, this work begins with an elementary review of statistics fundamentals, and then progressively increases in sophistication as the coverage is extended to the theory and practice of linear and nonlinear least squares. The results are illustrated in application to data analysis problems important in the life sciences. The review of fundamentals includes the role of sampling and its connection to probability distributions, the Central Limit Theorem, and the importance of finite variance. Linear least squares are presented using matrix notation, and the significance of the key probability distributions-Gaussian, chi-square, and t-is illustrated with Monte Carlo calculations. The meaning of correlation is discussed, including its role in the propagation of error. When the data themselves are correlated, special methods are needed for the fitting, as they are also when fitting with constraints. Nonlinear fitting gives rise to nonnormal parameter distributions, but the 10% Rule of Thumb suggests that such problems will be insignificant when the parameter is sufficiently well determined. Illustrations include calibration with linear and nonlinear response functions, the dangers inherent in fitting inverted data (e.g., Lineweaver-Burk equation), an analysis of the reliability of the van't Hoff analysis, the problem of correlated data in the Guggenheim method, and the optimization of isothermal titration calorimetry procedures using the variance-covariance matrix for experiment design. The work concludes with illustrations on assessing and presenting results. PMID:17964948

Tellinghuisen, Joel

2008-01-01

446

Relativistic spinor equation of photon  

E-print Network

In this paper, we have proposed the spiron equation of free and non-free photon, and give the spin operator and spin wave function of photon. We calculate the helicity of photon and prove there are left-handed and right-handed photon. By the spiron equation of non-free photon, we can study the quantum property of photon in medium, which can be used in quantum optics, photonic crystals and so on.

Xiang-Yao Wu; Hong Li; Xiao-Jing Liu; Si-Qi Zhang; Ji Ma; Guang-Huai Wang; Hai-Xin Gao; Heng-Mei Li; Hong-Chun Yuan

2014-01-02

447

Directory of Michigan Library Statistics. 1994 Edition. Reporting 1992 and 1993 Statistical Activities including: Public Library Statistics, Library Cooperative Statistics, Regional/Subregional Statistics.  

ERIC Educational Resources Information Center

This edition focuses on statistical data supplied by Michigan public libraries, public library cooperatives, and those public libraries which serve as regional or subregional outlets for blind and physically handicapped services. Since statistics in Michigan academic libraries are typically collected in odd-numbered years, they are not included…

Leaf, Donald C., Comp.; Neely, Linda, Comp.

448

U. S. Teenage Pregnancy Statistics  

NSDL National Science Digital Library

The Alan Guttmacher Institute (AGI) is a nonpartisan organization that provides research, policy analysis, and public education about reproductive health. Recently, the AGI posted this special statistical report on teenage pregnancy in the US. The report consists of two large data tables synthesizing pregnancy statistics from 1972 to 1996. The first table provides the number of births, number of legal abortions, number of estimated miscarriages, and total number of pregnancies in the US between 1972 and 1996 for five different age distributions: fourteen or younger, fifteen to seventeen, eighteen to nineteen, fifteen to nineteen, and under twenty. The second table provides birth rates, abortion rates, and pregnancy rates per 1,000 women for the same years and age distributions as the first table. For both tables, data refer to the age of the women at time of pregnancy outcome, not at the time of conception. A list of statistical sources are included.

1998-01-01

449

[Statistical surveys].  

PubMed

Data are included on territory and population in Czechoslovakia; population development, 1869-1980; resident population by sex, 1970 and 1980; population by broad age group, 1970 and 1980; population by nationality, 1980; economic activity; housing; population density; natural increase, 1971-1980; number of women aged 15-29, 1978-1980; marriage and divorce, 1978-1980; abortion, live births, and reproduction rate, 1978-1980; population over age 60, 1978-1980; mortality and life expectancy, 1978-1980; infant and neonatal mortality, 1978-1980; mortality and causes of death, 1979-1980; infant mortality by cause, 1979-1980; internal and international migration, 1978-1980; sex ratio, 1978-1980; and natural increase, 1975-1981. PMID:12158178

1981-01-01

450

State-dependent photon blockade via quantum-reservoir engineering  

E-print Network

An arbitrary initial state of an optical or microwave field in a lossy driven nonlinear cavity can be changed, in the steady-state limit, into a partially incoherent superposition of only the vacuum and the single-photon states. This effect is known as single-photon blockade, which is usually analyzed for a Kerr-type nonlinear cavity parametrically driven by a single-photon process assuming single-photon loss mechanisms. We study photon blockade engineering via a squeezed reservoir, i.e., a quantum reservoir, where only two-photon absorption is allowed. Namely, we analyze a lossy nonlinear cavity parametrically driven by a two-photon process and allowing two-photon loss mechanisms, as described by the master equation derived for a two-photon absorbing reservoir. The nonlinear cavity engineering can be realized by a linear cavity with a tunable two-level system via the Jaynes-Cummings interaction in the dispersive limit. We show that by tuning properly the frequencies of the driving field and the two-level system, the steady state of the cavity field can be the single-photon Fock state or a partially incoherent superposition of several Fock states with photon numbers, e.g., (0,2), (1,3), (0,1,2), or (0,2,4). We observe that an arbitrary initial coherent or incoherent superposition of Fock states with an even (odd) number of photons can be changed into a partially incoherent superposition of a few Fock states of the same photon-number parity. A general solution for an arbitrary initial state is a weighted mixture of the above two solutions with even and odd photon numbers, where the weights are given by the probabilities of measuring the even and odd numbers of photons of the initial cavity field, respectively. Thus, in contrast to the standard photon blockade, we prove that the steady state in the engineered photon blockade, can depend on its initial state.

Adam Miranowicz; Jiri Bajer; Malgorzata Paprzycka; Yu-xi Liu; Alexandre M. Zagoskin; Franco Nori

2014-07-22

451

Photonic Hyper-Crystals  

E-print Network

We introduce a new "universality class" of artificial optical media - photonic hyper-crystals. These hyperbolic metamaterials with periodic spatial variation of dielectric permittivity on subwavelength scale, combine the features of optical metamaterials and photonic crystals. In particular, surface waves supported by a hyper-crystal, possess the properties of both the optical Tamm states in photonic crystals and surface plasmon polaritons at the metal-dielectric interface.

Narimanov, Evgenii E

2014-01-01

452

Photonically Engineered Incandescent Emitter  

DOEpatents

A photonically engineered incandescence is disclosed. The emitter materials and photonic crystal structure can be chosen to modify or suppress thermal radiation above a cutoff wavelength, causing the emitter to selectively emit in the visible and near-infrared portions of the spectrum. An efficient incandescent lamp is enabled thereby. A method for fabricating a three-dimensional photonic crystal of a structural material, suitable for the incandescent emitter, is also disclosed.

Gee, James M. (Albuquerque, NM); Lin, Shawn-Yu (Albuquerque, NM); Fleming, James G. (Albuquerque, NM); Moreno, James B. (Albuquerque, NM)

2005-03-22

453

National Photonics Skill Standards  

NSDL National Science Digital Library

This document marks an important milestone in the development and maintenance of high-quality associate degree programs in photonics in U.S. community and technical colleges. The need for photonics education is critical. The problem cannot be remedied through on-the-job training. Our public educational institutions, particularly two-year colleges, must get involved. But most cannot do so without guidelines for determining what knowledge and skills photonics graduates will need in the coming years.

2008-11-17

454

Statistics (Program Description)  

NSF Publications Database

... of Mathematical Sciences Statistics Description The Statistics Program supports research for ... robust methods, experimental design, spatial statistics, resampling methods, and the analysis of ...

455

Methodology, Measurement, and Statistics  

NSF Publications Database

... federal statistical agencies for competitive survey and statistical methodology proposals.) Proposal ... models that cross traditional disciplinary boundaries, including research on statistical methodology ...

456

Photons from Heavy-Ion Collisions at Fermi Velocity  

E-print Network

'I ~ (+l Ii & & .~ I + I I 'f Il I I PHYSICAL REVIEW C VOLUME 35, NUMBER 5 MAY 1987 Photons from heavy-ion collisions at Fermi velocity Che Ming Ko Center for Theoretical Physics, Physics Department and Cyclotron Institute, Texas Ad... December 1986) The production of photons from heavy-ion collisions at intermediate energies is studied in the model based on the Boltzmann-Uehling-Uhlenbeck equation. Taking into account photon produc- tion from nucleon-nucleon collisions...

Ko, Che Ming; Alchelin, J.

1987-01-01

457

Three-photon N00N states generated by photon subtraction from double photon pairs.  

PubMed

We describe an experimental demonstration of a novel three-photon N00N state generation scheme using a single source of photons based on spontaneous parametric down-conversion (SPDC). The three-photon entangled state is generated when a photon is subtracted from a double pair of photons and detected by a heralding counter. Interference fringes measured with an emulated three-photon detector reveal the three-photon de Broglie wavelength and exhibit visibility > 70% without background subtraction. PMID:19997192

Kim, Heonoh; Park, Hee Su; Choi, Sang-Kyung

2009-10-26

458

Photonics in transportation  

NASA Astrophysics Data System (ADS)

In transportation, photonics helps save lives and improves safety. A vehicle - whether it is drawn, floated or driven - carries stringent physical limitations. Any photonic hardware will increase the vehicle's weight, space and power consumption. But this hardware will improve safety for drivers and passengers. Photonics also helps to inspect railroads and highways. Lasers, smart imagers and computers for data processing offer a range of capabilities for transportation industry. The proposed paper will discuss the state of the art in the area of photonic applications for transportation.

Inozemtsev, Vladimir G.; Shilin, Victor A.; Syster, Vladimir G.

2002-04-01

459

Explorations in statistics: power  

NSDL National Science Digital Library

Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This fifth installment of Explorations in Statistics revisits power, a concept fundamental to the test of a null hypothesis. Power is the probability that we reject the null hypothesis when it is false. Four things affect power: the probability with which we are willing to rejectÃÂby mistakeÃÂa true null hypothesis, the magnitude of the difference we want to be able to detect, the variability of the underlying population, and the number of observations in our sample. In an application to an Institutional Animal Care and Use Committee or to the National Institutes of Health, we define power to justify the sample size we propose.

Douglas Curran-Everett (University of Colorado Physiology and Biophysics)

2010-06-01

460

Parameter Estimation in Astronomy with Poisson-Distributed Data. II. The Modified Chi-Square-Gamma Statistic  

E-print Network

I investigate the use of Pearson's chi-square statistic, the Maximum Likelihood Ratio statistic for Poisson distributions, and the chi-square-gamma statistic (Mighell 1999, ApJ, 518, 380) for the determination of the goodness-of-fit between theoretical models and low-count Poisson-distributed data. I demonstrate that these statistics should not be used to determine the goodness-of-fit with data values of 10 or less. I modify the chi-square-gamma statistic for the purpose of improving its goodness-of-fit performance. I demonstrate that the modified chi-square-gamma statistic performs (nearly) like an ideal chi-square statistic for the determination of goodness-of-fit with low-count data. On average, for correct (true) models, the mean value of modified chi-square-gamma statistic is equal to the number of degrees of freedom (nu) and its variance is 2*nu --- like the chi-square distribution for nu degrees of freedom. Probabilities for modified chi-square-gamma goodness-of-fit values can be calculated with the incomplete gamma function. I give a practical demonstration showing how the modified chi-square-gamma statistic can be used in experimental astrophysics by analyzing simulated X-ray observations of a weak point source (signal-to-noise ratio of 5.2; 40 photons spread over 317 pixels) on a noisy background (0.06 photons per pixel). Accurate estimates (95% confidence intervals/limits) of the location and intensity of the X-ray point source are determined.

Kenneth J. Mighell

2000-07-21

461

Effect of Loss on Multiplexed Single-Photon Sources  

E-print Network

An on-demand single-photon source is a key requirement for scaling many optical quantum technologies. A promising approach to realize an on-demand single-photon source is to multiplex an array of heralded single-photon sources using an active optical switching network. However, the performance of multiplexed sources is degraded by photon loss in the optical components and the non-unit detection efficiency of the heralding detectors. We provide a theoretical description of a general multiplexed single-photon source with lossy components and derive expressions for the output probabilities of single-photon emission and multi-photon contamination. We apply these expressions to three specific multiplexing source architectures and consider their tradeoffs in design and performance. To assess the effect of lossy components on near- and long-term experimental goals, we simulate the multiplexed sources when used for many-photon state generation under various amounts of component loss. We find that with a multiplexed source composed of switches with ~0.2-0.4 dB loss and high efficiency number-resolving detectors, a single-photon source capable of efficiently producing 20-40 photon states with low multi-photon contamination is possible, offering the possibility of unlocking new classes of experiments and technologies.

Damien Bonneau; Gabriel J. Mendoza; Jeremy L. O'Brien; Mark G. Thompson

2014-09-18

462

Experimental generation of single photons via active multiplexing  

SciTech Connect

An on-demand single-photon source is a fundamental building block in quantum science and technology. We experimentally demonstrate the proof of concept for a scheme to generate on-demand single photons via actively multiplexing several heralded photons probabilistically produced from pulsed spontaneous parametric down-conversions (SPDCs). By utilizing a four-photon-pair source, an active feed-forward technique, and an ultrafast single-photon router, we show a fourfold enhancement of the output photon rate. Simultaneously, we maintain the quality of the output single-photon states, confirmed by correlation measurements. We also experimentally verify, via Hong-Ou-Mandel interference, that the router does not affect the indistinguishability of the single photons. Furthermore, we give numerical simulations, which indicate that photons based on multiplexing of four SPDC sources can outperform the heralding based on highly advanced photon-number-resolving detectors. Our results show a route for on-demand single-photon generation and the practical realization of scalable linear optical quantum-information processing.

Ma Xiaosong; Zotter, Stefan; Kofler, Johannes [Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna (Austria); Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria); Jennewein, Thomas [Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna (Austria); Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1 (Canada); Zeilinger, Anton [Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna (Austria); Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria); Vienna Centre for Quantum Science and Technology, Boltzmanngasse 3, A-1090, Vienna (Austria)

2011-04-15

463

History of Prime Numbers  

NSDL National Science Digital Library

The School of Mathematics and Statistics at the University of St Andrews, Scotland has developed an extensive collection of articles on the history of mathematics (See also NSDL Scout Report for Math, Engineering, and Technology, June 4, 2004). This article, written by J J O'Connor and E F Robertson, reviews the history of Prime Numbers. The article includes hyperlinks to topics addressed further in other sections of the website. For example, from this website visitors can also find articles on Pythagoras and Euclid.

464

Light Higgs Production at a Photon Collider  

E-print Network

We present a preliminary study of the production of a light Higgs boson with a mass between 120 and 160 GeV in photon-photon collisions at a Compton collider. The event generator for the backgrounds to a Higgs signal due to bbbar and ccbar heavy quark pair production in polarized Gamma-Gamma collisions is based on a complete next-to-leading order (NLO) perturbative QCD calculation. For J_z=0 the large double-logarithmic corrections up to four loops are also included. It is shown that the two-photon width of the Higgs boson can be measured with high statistical accuracy of about 2-10% for integrated Gamma-Gamma luminosity in the hard part of the spectrum of 43 fb-1. From this result the total Higgs boson width can be derived in a model independent way.

G. Jikia; S. Soldner-Rembold

2001-01-30

465

Single Photon Source Using Laser Pulses and Two-Photon Absorption  

E-print Network

We have previously shown that two-photon absorption (TPA) and the quantum Zeno effect can be used to make deterministic quantum logic devices from an otherwise linear optical system. Here we show that this type of quantum Zeno gate can be used with additional two-photon absorbing media and weak laser pulses to make a heralded single photon source. A source of this kind is expected to have a number of practical advantages that make it well suited for large scale quantum information processing applications.

B. C. Jacobs; T. B. Pittman; J. D. Franson

2006-03-15

466

A Study of Properties of the Photonic Band Gap of Unmagnetized Plasma Photonic Crystal  

NASA Astrophysics Data System (ADS)

In this study, the propagation of electromagnetic waves in one-dimensional plasma photonic crystals (PPCs), namely, superlattice structures consisting alternately of a homogeneous unmagnetized plasma and dielectric material, is simulated numerically using the finite-difference time-domain (FDTD) algorithm. A perfectly matched layer (PML) absorbing technique is used in this simulation. The reflection and transmission coefficients of electromagnetic (EM) waves through PPCs are calculated. The characteristics of the photonic band gap (PBG) are discussed in terms of plasma density, dielectric constant ratios, number of periods, and introduced layer defect. These may provide some useful information for designing plasma photonic crystal devices.

Liu, Song; Zhong, Shuangying; Liu, Sanqiu

2009-02-01

467

TestU01: A C Library for Empirical Testing of Random Number Generators  

E-print Network

- tics]--Random number generation, statistical software General Terms: Algorithms, Experimentation Additional Key Words and Phrases: Statistical software, random number generators, random num- ber tests

L'Ecuyer, Pierre

468

SOCR: Statistics Online Computational Resource.  

PubMed

The need for hands-on computer laboratory experience in undergraduate and graduate statistics education has been firmly established in the past decade. As a result a number of attempts have been undertaken to develop novel approaches for problem-driven statistical thinking, data analysis and result interpretation. In this paper we describe an integrated educational web-based framework for: interactive distribution modeling, virtual online probability experimentation, statistical data analysis, visualization and integration. Following years of experience in statistical teaching at all college levels using established licensed statistical software packages, like STATA, S-PLUS, R, SPSS, SAS, Systat, etc., we have attempted to engineer a new statistics education environment, the Statistics Online Computational Resource (SOCR). This resource performs many of the standard types of statistical analysis, much like other classical tools. In addition, it is designed in a plug-in object-oriented architecture and is completely platform independent, web-based, interactive, extensible and secure. Over the past 4 years we have tested, fine-tuned and reanalyzed the SOCR framework in many of our undergraduate and graduate probability and statistics courses and have evidence that SOCR resources build student's intuition and enhance their learning. PMID:21451741

Dinov, Ivo D

2006-10-01

469

SOCR: Statistics Online Computational Resource  

PubMed Central

The need for hands-on computer laboratory experience in undergraduate and graduate statistics education has been firmly established in the past decade. As a result a number of attempts have been undertaken to develop novel approaches for problem-driven statistical thinking, data analysis and result interpretation. In this paper we describe an integrated educational web-based framework for: interactive distribution modeling, virtual online probability experimentation, statistical data analysis, visualization and integration. Following years of experience in statistical teaching at all college levels using established licensed statistical software packages, like STATA, S-PLUS, R, SPSS, SAS, Systat, etc., we have attempted to engineer a new statistics education environment, the Statistics Online Computational Resource (SOCR). This resource performs many of the standard types of statistical analysis, much like other classical tools. In addition, it is designed in a plug-in object-oriented architecture and is completely platform independent, web-based, interactive, extensible and secure. Over the past 4 years we have tested, fine-tuned and reanalyzed the SOCR framework in many of our undergraduate and graduate probability and statistics courses and have evidence that SOCR resources build student’s intuition and enhance their learning. PMID:21451741

Dinov, Ivo D.

2011-01-01

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