Adaptive Quantum Optics with Spatially Entangled Photon Pairs

Light shaping facilitates the preparation and detection of optical states and underlies many applications in communications, computing, and imaging. In this Letter, we generalize light shaping to the quantum domain. We show that patterns of phase modulation for classical laser light can also shape higher orders of spatial coherence, allowing deterministic tailoring of high-dimensional quantum entanglement. By modulating spatially entangled photon pairs, we create periodic, topological, and random patterns of quantum illumination, without effect on intensity. We then structure the quantum illumination to simultaneously compensate for entanglement that has been randomized by a scattering medium and to characterize the medium's properties via a quantum measurement of the optical memory effect. The results demonstrate fundamental aspects of spatial coherence and open the field of adaptive quantum optics

General model of photon-pair detection with an image sensor

We develop an analytic model that relates intensity correlation measurements performed by an image sensor to the properties of photon pairs illuminating it. Experiments using both an effective single-photon counting (SPC) camera and a linear electron-multiplying charge-coupled device (EMCCD) camera confirm the model

Quantum Phase Imaging using Spatial Entanglement

Entangled photons have the remarkable ability to be more sensitive to signal and less sensitive to noise than classical light. Joint photons can sample an object collectively, resulting in faster phase accumulation and higher spatial resolution, while common components of noise can be subtracted. Even more, they can accomplish this while physically separate, due to the nonlocal properties of quantum mechanics. Indeed, nearly all quantum optics experiments rely on this separation, using individual point detectors that are scanned to measure coincidence counts and correlations. Scanning, however, is tedious, time consuming, and ill-suited for imaging. Moreover, the separation of beam paths adds complexity to the system while reducing the number of photons available for sampling, and the multiplicity of detectors does not scale well for greater numbers of photons and higher orders of entanglement. We bypass all of these problems here by directly imaging collinear photon pairs with an electron-multiplying CCD camera. We show explicitly the benefits of quantum nonlocality by engineering the spatial entanglement of the illuminating photons and introduce a new method of correlation measurement by converting time-domain coincidence counting into spatial-domain detection of selected pixels. We show that classical transport-of-intensity methods are applicable in the quantum domain and experimentally demonstrate nearly optimal (Heisenberg-limited) phase measurement for the given quantum illumination. The methods show the power of direct imaging and hold much potential for more general types of quantum information processing and control

Integrating Case-Based Reasoning with Adaptive Process Management

The need for more flexiblity of process-aware information systems (PAIS) has been discussed for several years and different approaches for adaptive process management have emerged. Only few of them provide support for both changes of individual process instances and the propagation of process type changes to a collection of related process instances. The knowledge about changes has not yet been exploited by any of these systems. To overcome this practical limitation, PAIS must capture the whole process life cycle and all kinds of changes in an integrated way. They must allow users to deviate from the predefined process in exceptional situations, and assist them in retrieving and reusing knowledge about previously performed changes. In this report we present a proof-of concept implementation of a learning adaptive PAIS. The prototype combines the ADEPT2 framework for dynamic process changes with concepts and methods provided by case-based reasoning(CBR) technology

Basic Concepts in the Philosophy of Gottfried Keller

Originally published in 1949, this volume contains a skillful analysis of the concepts of "Natur" and "Freiheit" and their influence on Keller's ideas in the fields of ethics, aesthetics, and politics, supported by pertinent passages from Keller's work. Reichert divides Keller's works into two time periods, and includes a discussion of Schiller's influence on Keller

An experimental comparison of nonswirling and swirling flow in a circular-to-rectangular transition duct

Circular-to-rectangular transition ducts are used as exhaust system components of aircraft with rectangular exhaust nozzles. Often, the incoming flow of these transition ducts includes a swirling velocity component remaining from the gas turbine engine. Previous transition duct studies have either not included inlet swirl or when inlet swirl was considered, only overall performance parameters were evaluated. Circular-to-rectangular transition duct flows with and without inlet swirl were explored in order to understand the effect of inlet swirl on the transition duct flow field and to provide detailed duct flow data for comparison with numerical code predictions. A method was devised to create a swirling, solid body rotational flow with minimal associated disturbances. Coefficients based on velocities and total and static pressures measured incross stream planes at four axial locations within the transition duct, along with surface static pressure measurements and surface oil film visualization, are presented for both nonswirling and swirling incoming flow. In both cases the inlet centerline Mach number was 0.35. The Reynolds number based on the inlet centerline velocity and duct inlet diameter was 1,547,000 for nonswirling and 1,366,000 for swirling flow. The maximum swirl angle was 15.6 deg. Two pair of counter-rotating side wall vortices appeared in the duct flow without inlet swirl. These vortices were absent in the swirling incoming flow cases

An experimental trace gas investigation of fluid transport and mixing in a circular-to-rectangular transition duct

An ethylene trace gas technique was used to map out fluid transport and mixing within a circular to rectangular transition duct. Ethylene gas was injected at several points in a cross stream plane upstream of the transition duct. Ethylene concentration contours were determined at several cross stream measurement planes spaced axially within the duct. The flow involved a uniform inlet flow at a Mach number level of 0.5. Statistical analyses were used to quantitatively interpret the trace gas results. Also, trace gas data were considered along with aerodynamic and surface flow visualization results to ascertain transition duct flow phenomena. Convection of wall boundary layer fluid by vortices produced regions of high total pressure loss in the duct. The physical extent of these high loss regions is governed by turbulent diffusion

Phenomenology of the minimal supersymmetric U(1)B−L×U(1)RU(1)_{B-L}\times U(1)_R extension of the standard model

We discuss the minimal supersymmetric $U(1)_{B-L}\times U(1)_R$ extension of the standard model. Gauge couplings unify as in the MSSM, even if the scale of $U(1)_{B-L}\times U(1)_R$ breaking is as low as order TeV and the model can be embedded into an SO(10) grand unified theory. The phenomenology of the model differs in some important aspects from the MSSM, leading potentially to rich phenomenology at the LHC. It predicts more light Higgs states and the mostly left CP-even Higgs has a mass reaching easily 125 GeV, with no constraints on the SUSY spectrum. Right sneutrinos can be the lightest supersymmetric particle, changing all dark matter constraints on SUSY parameter space. The model has seven neutralinos and squark/gluino decay chains involve more complicated cascades than in the MSSM. We also discuss briefly low-energy and accelerator constraints on the model, where the most important limits come from recent $Z'$ searches at the LHC and upper limits on lepton flavour violation.Comment: 46 pages, 11 figure

Optimizing the signal-to-noise ratio of biphoton distribution measurements

Single-photon-sensitive cameras can now be used as massively parallel coincidence counters for entangled photon pairs. This enables measurement of biphoton joint probability distributions with orders-of-magnitude greater dimensionality and faster acquisition speeds than traditional raster scanning of point detectors; to date, however, there has been no general formula available to optimize data collection. Here we analyze the dependence of such measurements on count rate, detector noise properties, and threshold levels. We derive expressions for the biphoton joint probability distribution and its signal-to-noise ratio (SNR), valid beyond the low-count regime up to detector saturation. The analysis gives operating parameters for global optimum SNR that may be specified prior to measurement. We find excellent agreement with experimental measurements within the range of validity, and discuss discrepancies with the theoretical model for high thresholds. This work enables optimized measurement of the biphoton joint probability distribution in high-dimensional joint Hilbert spaces.Comment: 9 pages, 5 figures, 1 tabl