Active and Quantum Integrated Photonic Elements by Ion Exchange in Glass

Ion exchange in glass has a long history as a simple and effective technology to produce gradient-index structures and has been largely exploited in industry and in research laboratories. In particular, ion-exchanged waveguide technology has served as an excellent platform for theoretical and experimental studies on integrated optical circuits, with successful applications in optical communications, optical processing and optical sensing. It should not be forgotten that the ion-exchange process can be exploited in crystalline materials, too, and several crucial devices, such as optical modulators and frequency doublers, have been fabricated by ion exchange in lithium niobate. Here, however, we are concerned only with glass material, and a brief review is presented of the main aspects of optical waveguides and passive and active integrated optical elements, as directional couplers, waveguide gratings, integrated optical amplifiers and lasers, all fabricated by ion exchange in glass. Then, some promising research activities on ion-exchanged glass integrated photonic devices, and in particular quantum devices (quantum circuits), are analyzed. An emerging type of passive and/or reconfigurable devices for quantum cryptography or even for specific quantum processing tasks are presently gaining an increasing interest in integrated photonics; accordingly, we propose their implementation by using ion-exchanged glass waveguides, also foreseeing their integration with ion-exchanged glass lasersThis research was funded by Xunta de Galicia, Consellería de Educación, Universidades e FP, Grant GRC Number ED431C2018/11S

Rare-earth doped glasses and light managing in solar cells

Glasses doped with rare earth elements possess unique photoluminescence properties. They find application in several devices, such as lasers, optical amplifiers, and sensors. More recently, rare-earth doped glass thin films have been the subject of investigation for the development of frequency-converting layers able to increase the efficiency of silicon solar cells. Another approach to the improvement of the performance of a solar cell is based on the capture of a larger flux of light by the detector, which can be obtained by surface texture, plasmonics, or waveguide structures. Here, the recent advances in this area will be briefly reviewed

Imaging of a Case of Extramedullary Solitary Plasmacytoma of the Trachea

We describe a case of extramedullary tracheal plasmacytoma that was incidentally discovered in a 73-year-old man on a PET scan performed for assessing the extent of colon cancer. CT scan showed the tumor; multiplanar reformation coupled with virtual bronchoscopy allowed proper treatment planning. The tracheal tumor was resected during rigid bronchoscopy. Relevant investigations excluded multiple myeloma. Follow-up CT showed persistent thickening of the tracheal wall, but there has been no recurrence after one-year followup

prenatal mr imaging detection of deep medullary vein involvement in fetal brain damage

SUMMARY: Looking for anomalies distributed in DMV territory, we reviewed 78 fetal MR imaging examinations performed at our institution reporting unequivocal cerebral clastic lesions. We selected 3 cases, all of which had severe cardiocirculatory failure and parenchymal frontoparietal WM hemorrhagic lesions with characteristic fan-shaped distribution. Brain edema and other signs of venous hypertension were also evident. Our data suggest that in utero transient venous hypertension may be responsible for the onset of atypical frontal-located PVL

Pre-therapeutic histological and cytological assessment in head and neck squamous cell carcinomas. French Society of Otorhinolaryngology Guidelines – 2012

SummaryObjectivesThe authors present the French Society of Otorhinolaryngology (SFORL) guidelines for histopathologic assessment of head and neck cancer.Materiel and methodsA multidisciplinary workgroup set up by the SFORL performed an exhaustive review of the literature according to levels of evidence, following the 2000 guidelines of the French national health approvals and assessment agency (ANAES).ResultsComparison between histologic and clinical data is essential. In case of discrepancy between clinical, radiological and histological findings, reinterpretation or new biopsy may be required (professional consensus). Mere suspicion of carcinoma on fine-needle aspiration lymph-node biopsy only exceptionally warrants aggressive treatment (professional consensus). Exploration for HPV is not recommended as routine practice, being without therapeutic impact (professional consensus). Anti-p16 immunohistochemistry is optional, for epidemiological purposes (professional consensus). Tumor-bank tissue storage must conform strictly to prevailing legislation and good practice rules for sampling and preservation (professional consensus).ConclusionPathology assessment is mandatory in suspected H&N squamous cell carcinoma. The present guidelines are intended to optimize management

Diagnostic Value of Prenatal MR Imaging in the Detection of Brain Malformations in Fetuses before the 26th Week of Gestational Age

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Microspherical laser in Erbium-Ytterbium-doped glass

session A « Micro laser sources » [A3]International audienceWe present experimental results on a Er3+/Yb3+ doped microspherical laser. Our experiments have been focused on the 4I13/2 → 4I15/2 transition at 1550 nm of erbium ions in phosphate glass spheres. We also report on the effects that the interaction between the WGM modes of the glass sphere and an external metallic mirror has on the laser emission

Variability of Forebrain Commissures in Callosal Agenesis: A Prenatal MR Imaging Study

BACKGROUND AND PURPOSE: Agenesis of the corpus callosum, even when isolated, may be characterized by anatomic variability. The aim of this study was to describe the types of other forebrain commissures in a large cohort of randomly enrolled fetuses with apparently isolated agenesis of the corpus callosum at prenatal MR imaging. MATERIALS AND METHODS: All fetuses with apparent isolated agenesis of the corpus callosum undergoing prenatal MR imaging from 2004 to 2014, were evaluated for the presence of the anterior or a vestigial hippocampal commissure assessed in consensus by 2 pediatric neuroradiologists. RESULTS: Overall, 62 cases of agenesis of the corpus callosum were retrieved from our data base. In 3/62 fetuses (4.8%), no forebrain commissure was visible at prenatal MR imaging, 23/62 fetuses (37.1%) presented with only the anterior commissure, and 20/62 fetuses (32.3%) showed both the anterior commissure and a residual vestigial hippocampal commissure, whereas in the remaining 16/62 fetuses (25.8%), a hybrid structure merging a residual vestigial hippocampal commissure and a rudiment of the corpus callosum body was detectable. Postnatal MR imaging, when available, confirmed prenatal forebrain commissure findings. CONCLUSIONS: Most fetuses with apparent isolated agenesis of the corpus callosum showed at least 1 forebrain commissure at prenatal MR imaging, and approximately half of fetuses also had a second commissure: a vestigial hippocampal commissure or a hybrid made of a hippocampal commissure and a rudimentary corpus callosum body. Whether such variability is the result of different genotypes and whether it may have any impact on the long-term neurodevelopmental outcome remains to be assessed. AC : anterior commissure ACC : agenesis of the corpus callosum CC : corpus callosum GA : gestational age HC : hippocampal commissure HS : hybrid structur

Ground deformation and associated hazards in NW peloponnese (Greece)

In the last decades, ground deformations were investigated, analysed and monitored using several methods. As a consequence of a spreading urbanization, several phenomena, e.g. landslide and subsidence, were emphasized or triggered causing not only socio-economic damages, but, in some cases, also casualties. The investigation and mapping of these phenomena are important for both local authorities and civil protection in order to promote a higher conscientious urban planning and to highlight the more hazardous areas. Furthermore, the information are a key point for social development connected to the awareness of the environment and the related risk. The Achaia prefecture, in the north-eastern Peloponnese (Greece), close to the Gulf of Patras, is an area strongly affected by subsidence and landslides. Furthermore, this is an earthquake-prone area, a factor that can trigger some mass movements. For this region, a landslide inventory was realized with the help of the interpretation of Persistent Scatterers data, for the period 1992–2008, and high-resolution optical satellite images, available until 2016, in addition to the investigation of the landslide State of Activity. Moreover, for the coastal area, a section was investigated to evidence subsidence

Nickel(II) 3,4;9,10-Perylenediimide bis-Phosphonate Pentahydrate: A Metal−Organic Ferromagnetic Dye

The new metal−organic compound nickel(II) 3,4;9,10- perylenediimide bis-phosphonate pentahydrate, i.e. Ni2[(PDI-BP)- (H2O)2]·3H2O (1), has been synthesized and its structural and magnetic properties have been studied. Reaction of 3,4;9,10-perylenediimide bisphosphonate (PDI-BP, hereafter) ligand and nickel chloride in water resulted in the precipitation of a red and poorly crystalline solid (1). As the solid shows a poor crystalline organization of aggregates, the energy dispersive X-ray diffraction analysis (EDXD) technique has been used to obtain short-range order structural information of the single nanoaggregates by radial distribution function analysis. The overall structure of the compound is characterized by layers containing perylene planes shifted in the direction perpendicular to the stacking axes in such a way that only the outer rings overlap. The edges of the perylene planes are connected to the phosphonate groups through an imido group. The oxygen atoms of the [−PO3]2‑ group and those of the water molecules are bonded to the nickel ions resulting in a [NiO6] octahedral coordination sphere. The Ni−O bond lengths are 0.21 ± 0.08 nm and the Ni−O−Ni angles of aligned moieties are 95 ± 2°. The oxygen atoms of the water molecules and the nickel atoms are nearly planar and almost perpendicular to the perylene planes forming chains of edge-sharing octahedra. The magnetic properties of (1) show the presence of intrachain ferromagnetic Ni−Ni interactions and a long-range ferromagnetic order below 21 K with a canting angle and with a spin glasslike behavior due to disorder in the inorganic layer. Hysteresis cycles show a coercive field of ca. 272 mT at 2 K that decreases as the temperature is increased and vanishes at ca. 20 K