Discriminating quantum-optical beam-splitter channels with number-diagonal signal states: Applications to quantum reading and target detection

We consider the problem of distinguishing, with minimum probability of error, two optical beam-splitter channels with unequal complex-valued reflectivities using general quantum probe states entangled over M signal and M' idler mode pairs of which the signal modes are bounced off the beam splitter while the idler modes are retained losslessly. We obtain a lower bound on the output state fidelity valid for any pure input state. We define number-diagonal signal (NDS) states to be input states whose density operator in the signal modes is diagonal in the multimode number basis. For such input states, we derive series formulas for the optimal error probability, the output state fidelity, and the Chernoff-type upper bounds on the error probability. For the special cases of quantum reading of a classical digital memory and target detection (for which the reflectivities are real valued), we show that for a given input signal photon probability distribution, the fidelity is minimized by the NDS states with that distribution and that for a given average total signal energy N_s, the fidelity is minimized by any multimode Fock state with N_s total signal photons. For reading of an ideal memory, it is shown that Fock state inputs minimize the Chernoff bound. For target detection under high-loss conditions, a no-go result showing the lack of appreciable quantum advantage over coherent state transmitters is derived. A comparison of the error probability performance for quantum reading of number state and two-mode squeezed vacuum state (or EPR state) transmitters relative to coherent state transmitters is presented for various values of the reflectances. While the nonclassical states in general perform better than the coherent state, the quantitative performance gains differ depending on the values of the reflectances.Comment: 12 pages, 7 figures. This closely approximates the published version. The major change from v2 is that Section IV has been re-organized, with a no-go result for target detection under high loss conditions highlighted. The last sentence of the abstract has been deleted to conform to the arXiv word limit. Please see the PDF for the full abstrac

Quantum entanglement distribution with 810 nm photons through telecom fibers

We demonstrate the distribution of polarization entangled photons of wavelength 810 nm through standard telecom fibers. This technique allows quantum communication protocols to be performed over established fiber infrastructure, and makes use of the smaller and better performing setups available around 800 nm, as compared to those which use telecom wavelengths around 1550 nm. We examine the excitation and subsequent quenching of higher-order spatial modes in telecom fibers up to 6 km in length, and perform a distribution of high quality entanglement (visibility 95.6%). Finally, we demonstrate quantum key distribution using entangled 810 nm photons over a 4.4 km long installed telecom fiber link.Comment: 5 pages, 5 figures, 1 tabl

Role of entanglement in two-photon imaging

The use of entangled photons in an imaging system can exhibit effects that cannot be mimicked by any other two-photon source, whatever the strength of the correlations between the two photons. We consider a two-photon imaging system in which one photon is used to probe a remote (transmissive or scattering) object, while the other serves as a reference. We discuss the role of entanglement versus correlation in such a setting, and demonstrate that entanglement is a prerequisite for achieving distributed quantum imaging.Comment: 15 pages, 2 figure

Assessment of pulmonary hypertension in patients with liver disease pre and post liver transplantation

AbstractBackgroundBoth hepatopulmonary syndrome and portopulmonary hypertension are associated with chronic liver disease. Liver transplantation is considered a controversial solution.AimThe aim of this work is to assess pulmonary hypertension in liver disease patients pre and post liver transplantation. Studying the impact of pulmonary hypertension on hemodynamic of the patients in hospital after liver transplantation.Patients and methodsEcho cardiographic examination pre and post liver transplantation after at least 3months was conducted on 20 patients with chronic liver diseases and pulmonary hypertension who underwent liver transplantation to estimate mean PAP and degree of tricuspid regurgitation.ResultsThe present study was conducted on 20 patients consisting of 18 males (90%) and two females (10%) with mean age 47.8±8.9. It showed that mean pulmonary arterial pressure improved after liver transplantation 24.65%±17.50.The tricuspid regurgitation before operation was mild in 17 patients (85%) and moderate in three patients (15%) and after operation it become normal in 40% and mild in 60% with improvement in 55% and no improvement in 45% of the patients. There was improvement in dyspnea scale after the operation with one grade change in 35%, two grade change in 55% and three grade change in 10% of patients.ConclusionLiver transplantation was effective in the reduction of pulmonary artery pressure. The degree of pulmonary hypertension affected the functional state according to WHO Classification of pulmonary hypertension patients

In-Vitro Anthelmintic Efficacy Of Crude Aqueous Extracts Of Neem (Azadirachta Indica) Leaf, Stem And Root On Nematode

The anthelmintic efficacy of the aqueous extracts o neem (Azadirachta indica) leaf and stem and root barks against the hatching of eggs and the survival of larvae of nematode parasites of small ruminants were studied. The results of the in vitro egg hatch assay showed that the aqueous extracts of the leaf and stem bark produced significant anthelmintic effect through reduction in nematode egg hatch. The reduction in egg hatch was concentration dependent being highest (51 % and 50 % for the leaf and stem bark extracts respectively) at the highest concentration (100 mg/ml) of the extracts but inferior to those produced by albendazoe (100 % at 40 mg/ml). Aqueous extracts of the leaf and root bark produced significant reduction in larval survival within 60 minutes at ambienttemperature (30 – 35 ºC). Larval death was similar in both extracts and concentration dependent, increasing with increasing concentration of the leaf and root bark extracts. The reduction in larval survival due to the extracts was similar to that produced by albendazole. In general, the aqueous extract of neem leaf was more efficacious in limiting nematode larvae survival and in-vitro egg hatch. The results confirm the folkloric claims that neem has anthelmintic effect and thus suggest its possible usefulness as an anthelmintic. Keywords: Anthelmintic efficacy, Aqueous extract, Leaf, Stem, Root, Bark, Azadirachta indicaAnimal Research International Vol. 3 (3) 2006 pp. 549-55

IR optical fiber-based noncontact pyrometer for drop tube instrumentation

The design of a two color pyrometer with infrared optical fiber bundles for collection of the infrared radiation is described. The pyrometer design is engineered to facilitate its use for measurement of the temperature of small, falling samples in a microgravity materials processing experiment using a 100 meter long drop tube. Because the samples are small and move rapidly through the field of view of the pyrometer, the optical power budget of the detection system is severly limited. Strategies for overcoming this limitation are discussed

Experimental Violation of Bell's Inequality in Spatial-Parity Space

We report the first experimental violation of Bell's inequality in the spatial domain using the Einstein--Podolsky--Rosen state. Two-photon states generated via optical spontaneous parametric downconversion are shown to be entangled in the parity of their one-dimensional transverse spatial profile. Superpositions of Bell states are prepared by manipulation of the optical pump's transverse spatial parity--a classical parameter. The Bell-operator measurements are made possible by devising simple optical arrangements that perform rotations in the one-dimensional spatial-parity space of each photon of an entangled pair and projective measurements onto a basis of even--odd functions. A Bell-operator value of 2.389 +- 0.016 is recorded, a violation of the inequality by more than 24 standard deviations.Comment: 10 pages, 3 figures, 1 Tabl

VIENA2: A Driving Anticipation Dataset

Action anticipation is critical in scenarios where one needs to react before the action is finalized. This is, for instance, the case in automated driving, where a car needs to, e.g., avoid hitting pedestrians and respect traffic lights. While solutions have been proposed to tackle subsets of the driving anticipation tasks, by making use of diverse, task-specific sensors, there is no single dataset or framework that addresses them all in a consistent manner. In this paper, we therefore introduce a new, large-scale dataset, called VIENA2, covering 5 generic driving scenarios, with a total of 25 distinct action classes. It contains more than 15K full HD, 5s long videos acquired in various driving conditions, weathers, daytimes and environments, complemented with a common and realistic set of sensor measurements. This amounts to more than 2.25M frames, each annotated with an action label, corresponding to 600 samples per action class. We discuss our data acquisition strategy and the statistics of our dataset, and benchmark state-of-the-art action anticipation techniques, including a new multi-modal LSTM architecture with an effective loss function for action anticipation in driving scenarios.Comment: Accepted in ACCV 201

Ionization-induced asymmetric self-phase modulation and universal modulational instability in gas-filled hollow-core photonic crystal fibers

We study theoretically the propagation of relatively long pulses with ionizing intensities in a hollow-core photonic crystal fiber filled with a Raman-inactive gas. Due to photoionization, previously unknown types of asymmetric self-phase modulation and `universal' modulational instabilities existing in both normal and anomalous dispersion regions appear. We also show that it is possible to spontaneously generate a plasma-induced continuum of blueshifting solitons, opening up new possibilities for pushing supercontinuum generation towards shorter and shorter wavelengths.Comment: 5 pages, 4 figure