Two-mode squeezed vacuum and squeezed light in correlated interferometry

We study in detail a system of two interferometers aimed to the detection of extremely faint phase-fluctuations. This system can represent a breakthrough for detecting a faint correlated signal that would remain otherwise undetectable even using the most sensitive individual interferometric devices, that are limited by the shot noise. If the two interferometers experience identical phase-fluctuations, like the ones introduced by the so called "holographic noise", this signal should emerge if their output signals are correlated, while the fluctuations due to shot noise and other independent contributions will vanish. We show how the injecting quantum light in the free ports of the interferometers can reduce the photon noise of the system beyond the shot-noise, enhancing the resolution in the phase-correlation estimation. We analyze both the use of two-mode squeezed vacuum or twin-beam state (TWB) and of two independent squeezing states. Our results basically confirms the benefit of using squeezed beams together with strong coherent beams in interferometry, even in this correlated case. However, mainly we concentrate on the possible use of TWB, discovering interesting and probably unexplored areas of application of bipartite entanglement and in particular the possibility of reaching in principle surprising uncertainty reduction

Direct experimental observation of nonclassicality in ensembles of single photon emitters

In this work we experimentally demonstrate for the first time a recently proposed criterion adressed to detect nonclassical behavior in the fluorescence emission of ensembles of single-photon emitters. In particular, we apply the method to study clusters of NV centres in diamond observed via single-photon-sensitive confocal microscopy. Theoretical considerations on the behavior of the parameter at any arbitrary order in presence of poissonian noise are presented and, finally, the opportunity of detecting manifold coincidences is discussed

BoWFire: Detection of Fire in Still Images by Integrating Pixel Color and Texture Analysis

Emergency events involving fire are potentially harmful, demanding a fast and precise decision making. The use of crowdsourcing image and videos on crisis management systems can aid in these situations by providing more information than verbal/textual descriptions. Due to the usual high volume of data, automatic solutions need to discard non-relevant content without losing relevant information. There are several methods for fire detection on video using color-based models. However, they are not adequate for still image processing, because they can suffer on high false-positive results. These methods also suffer from parameters with little physical meaning, which makes fine tuning a difficult task. In this context, we propose a novel fire detection method for still images that uses classification based on color features combined with texture classification on superpixel regions. Our method uses a reduced number of parameters if compared to previous works, easing the process of fine tuning the method. Results show the effectiveness of our method of reducing false-positives while its precision remains compatible with the state-of-the-art methods.Comment: 8 pages, Proceedings of the 28th SIBGRAPI Conference on Graphics, Patterns and Images, IEEE Pres

Towards joint reconstruction of noise and losses in quantum channels

The calibration of a quantum channel, i.e. the determination of the transmission losses affecting it, is definitely one of the principal objectives in both the quantum communication and quantum metrology frameworks. Another task of the utmost relevance is the identification, e.g. by extracting its photon number distribution, of the noise potentially present in the channel. Here we present a protocol, based on the response of a photon-number-resolving detector at different quantum efficiencies, able to accomplish both of these tasks at once, providing with a single measurement an estimate of the transmission losses as well as the photon statistics of the noise present in the exploited quantum channel. We show and discuss the experimental results obtained in the practical implementation of such protocol, with different kinds and levels of noise.Comment: 6 pages, 4 figure

Native NIR-emitting single colour centres in CVD diamond

Single-photon sources are a fundamental element for developing quantum technologies, and sources based on colour centres in diamonds are among the most promising candidates. The well-known NV centres are characterized by several limitations, thus few other defects have recently been considered. In the present work, we characterize in detail native efficient single colour centres emitting in the near infra-red in both standard IIa single-crystal and electronic-grade polycrystalline commercial CVD diamond samples. In the former case, a high-temperature annealing process in vacuum is necessary to induce the formation/activation of luminescent centres with good emission properties, while in the latter case the annealing process has marginal beneficial effects on the number and performances of native centres in commercially available samples. Although displaying significant variability in several photo physical properties (emission wavelength, emission rate instabilities, saturation behaviours), these centres generally display appealing photophysical properties for applications as single photon sources: short lifetimes, high emission rates and strongly polarized light. The native centres are tentatively attributed to impurities incorporated in the diamond crystal during the CVD growth of high-quality type IIa samples, and offer promising perspectives in diamond-based photonics.Comment: 27 pages, 10 figures. Submitted to "New Journal of Phsyics", NJP-100003.R

Coil embolization as an alternative endovascular approach for ruptured superficial femoral artery aneurysms

Purpose: True aneurysms of the superficial femoral artery (SFAA) are rare and, the endovascular approach using covered stents has gained more popularity. We report an endovascular alternative using embolization coils for treatment of a ruptured SFAA. Case description: An 88-old male admitted for a ruptured true SFAA (67×52mm in diameter and 70mm in length) presenting with painful mass pulsating in the proximal third of the left thigh. His surgical history consisted of an infrarenal abdominal aneurysm treated by open surgery and an ipsilateral popliteal aneurysm treated with prosthetic bypass by a medial approach; this was revealed to be occluded at the CT scan evaluation. The patient was asymptomatic for limb ischaemia, therefore we decided to perform embolization of the SFA with coils (MReye®Embolization Coil, Cook Medical, Bloomington,USA). Under local anaesthesia, via a 5-Fr sheath and an antegrade approach, coils were deployed first at the distal neck of the SFAA and then to its proximal neck. On the angiogram, complete aneurysm sac thrombosis with no leaks was achieved. At 6-month follow-up, the SFAA remained occluded, and the patient had not developed any sign of limb ischaemia. Conclusion: Coil embolization of SFAA in selected cases represents a feasible and safe endovascular alternative

Quantum state reconstruction using binary data from on/off photodetection

The knowledge of the density matrix of a quantum state plays a fundamental role in several fields ranging from quantum information processing to experiments on foundations of quantum mechanics and quantum optics. Recently, a method has been suggested and implemented in order to obtain the reconstruction of the diagonal elements of the density matrix exploiting the information achievable with realistic on/off detectors, e.g. silicon avalanche photo-diodes, only able to discriminate the presence or the absence of light. The purpose of this paper is to provide an overview of the theoretical and experimental developments of the on/off method, including its extension to the reconstruction of the whole density matrix.Comment: revised version, 11 pages, 6 figures, to appear as a review paper on Adv. Science Let

Systematic Review of Job Transition Programs Addressed to Youths With Intellectual Disability

This systematic review aimed to determine what existing job transition programs are evidence-based and methodologically founded. The PRISMA method was used for the review, and the inclusion criteria were to include studies where there were a description of transition programs and functional curriculum for acquiring employment competences; internship experiences in employment context; single-case or group-design studies with youths as participants; and diagnosis of intellectual disability. Forty-six studies were initially selected, and three final articles met all the criteria set for assessing the methodology quality. Although the review results show that more research is needed to provide empirical programs for enhancing the acquisition of employment capabilities, some evidence emerged from the analysis of studies. These concern mainly four aspects: curriculum contents facilitating the development of self-determination and the acquirement of job-related skills, chance to have individualized internships, support of job coaches, and technological solutions and programs anchored in community-based settings