336 research outputs found

    Ultra-low power generation of twin photons in a compact silicon ring resonator

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    We demonstrate efficient generation of correlated photon pairs by spontaneous four wave mixing in a 5 \mu m radius silicon ring resonator in the telecom band around 1550 nm. By optically pumping our device with a 200 \mu W continuous wave laser, we obtain a pair generation rate of 0.2 MHz and demonstrate photon time correlations with a coincidence-to-accidental ratio as high as 250. The results are in good agreement with theoretical predictions and show the potential of silicon micro-ring resonators as room temperature sources for integrated quantum optics applications.Comment: 8 pages, 3 figure

    Ensuring the identity of a user in time : a multi-modal fuzzy approach

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    This work proposes a fuzzy multimodal technique capable of guaranteeing the desired level of security while keeping under control the high costs typically associated to some biometric authentication devices. Specifically we describe a fuzzy controller choosing within a palette of authentication techniques to continuously check and confirm its trust in the identity of a user

    Knowledge Driven Behavioural Analysis in Process Intelligence

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    InthispaperweillustratehowtheknowledgedrivenBehaviourAnal- ysis, which has been used in the KITE.it process management framework, can support the evolution of analytics from descriptive to predictive. We describe how the methodology uses an iterative three-step process: first the descriptive knowledge is collected, querying the knowledge base, then the prescriptive and predictive knowledge phases allow us to evaluate business rules and objectives, extract unexpected business patterns, and screen exceptions. The procedure is iterative since this novel knowledge drives the definition of new descriptive an- alytics that can be combined with business rules and objectives to increase our level of knowledge on the combination between process behaviour and contex- tual information

    Micrometer-scale integrated silicon source of time-energy entangled photons

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    Entanglement is a fundamental resource in quantum information processing. Several studies have explored the integration of sources of entangled states on a silicon chip, but the devices demonstrated so far require millimeter lengths and pump powers of the order of hundreds of milliwatts to produce an appreciable photon flux, hindering their scalability and dense integration. Microring resonators have been shown to be efficient sources of photon pairs, but entangled state emission has never been proven in these devices. Here we report the first demonstration, to the best of our knowledge, of a microring resonator capable of emitting time-energy entangled photons. We use a Franson experiment to show a violation of Bell’s inequality by more than seven standard deviations with an internal pair generation exceeding 107 Hz. The source is integrated on a silicon chip, operates at milliwatt and submilliwatt pump power, emits in the telecom band, and outputs into a photonic waveguide. These are all essential features of an entangled state emitter for a quantum photonic network

    From Classical Four-Wave Mixing to Parametric Fluorescence in Silicon micro-ring resonators

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    Four-wave mixing can be stimulated or occur spontaneously. The first process is intrinsically much stronger, and well understood through classical nonlinear optics. The latter, also known as parametric fluorescence, can be explained only in the framework of a quantum theory of light. We experimentally demonstrate that, in a micro-ring resonator, there exists a simple relation between the efficiencies of these two processes, which is independent of the nonlinearity and size of the ring. In particular we show that the average power generated by parametric fluorescence can be immediately estimated from a classical FWM experiment. These results suggest that classical nonlinear characterization of a photonic integrated structure can provide accurate information on its nonlinear quantum properties.Comment: 4 pages, 3 figure

    Predicting candidemia in internal medicine departments: are we chasing the Holy Grail?

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    Candidemia is a challenging clinical condition with high rates of morbidity and mortality.1 Key requirements for its prompt management include early identification and timely initiation of appropriate systemic antifungal therapy, consistently reported as a major determinant of survival. However, the diagnosis of candidemia can be challenging and is often delayed as there are no specific clinical signs, blood cultures have low sensitivity, and detection of fungal blood cultures takes a long time. In addition, there is evidence that a significant percentage of such infections occurs in patients admitted to internal medicine departments. This is not particularly surprising given the advanced age of many inpatients at internal medicine departments and multiple complex comorbidities. Moreover, related therapies and healthcare system contacts often involve the use of central venous catheters and other indwelling devices, potentially entailing high risk of candidemia.2 Therefore, optimization of the diagnostic and therapeutic approach is an important and still unfulfilled need for the management of candidemia in internal medicine department
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