38 research outputs found

    Ultra-broadband Silicon Photonic Multimode Interference Coupler

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    In integrated optics, multimode interference couplers (MMIs) are used as light-wave splitters and combiners in a wide variety of devices ranging from spectrometers to sensors and coherent optical receivers. While their design and operation is generally well understood [1], the operational bandwidth remains limited. Here we present a sub-wavelength structured MMI, shown in Fig. 1(a), that overcomes this limitation and experimentally demonstrate a bandwidth exceeding 300nm at telecom wavelength, with more than 500nm bandwidth potentially attainable (as per 3D-FDTD simulations).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Effect of adjunctive perampanel on the quality of sleep and daytime somnolence in patients with epilepsy

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    Epilèpsia; Somnolència diürna; Fàrmacs antiepilèpticsEpilepsia; Somnolencia diurna; Fármacos antiepilépticosEpilepsy; Daytime somnolence; Antiepileptic drugsThis prospective uncontrolled study evaluated the effect of low-dose adjunctive perampanel therapy (4 mg/day for 3 months) on the sleep-wake cycle and daytime somnolence in adult patients (n = 10) with focal seizures. A > 50% reduction in the number of seizures was reported in 80% of the study patients; treatment had no significant effect on any sleep parameters as evident by the Maintenance of Wakefulness Test, Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale scores. Two patients reported dizziness with treatment. In conclusion, low-dose perampanel may improve seizure control without affecting the sleep characteristics or daytime somnolence in patients with epilepsy.This work was supported by Eisai Pharmaceuticals, Spain

    High performance silicon photonic devices based on practical metamaterials

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    Robert Halir, et al., "High performance silicon photonic devices based on practical metamaterials," OECC/PSC, 7-12 July 2019, Fukuoka (Japan)Subwavelength grating metamaterials are enabling a new generation of high-performance silicon photonic devices. Here we discuss the fundamental physics along with some of the latest advances in this rapidly expanding field.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministerio de Economía y Competitividad, Programa Estatal de Investigación Orientada a los Retos de la Sociedad (cofinanciado FEDER) – TEC2016-80718-R, TEC2015-71127-C2-1-R (FPI BES-2016-077798) and IJCI-2016-30484; Community of Madrid – S2018/NMT-4326, Marie Sklodowska-Curie –734331, Czech Science Foundation – 1900062

    An Ultracompact GRIN-Lens-Based Spot Size Converter using Subwavelength Grating Metamaterials

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    AbstractGraded‐index materials offer virtually complete control over light propagation in integrated photonic chips but can be challenging to implement. Here, an anisotropic graded‐index metamaterial, synthesized with fully etched silicon subwavelength structures, is proposed. Based on this material, a spot size converter that expands the transverse electric (TE) mode field profile from a 0.5 µm wide silicon wire waveguide to a 15 µm wide waveguide within a length of only 14 µm is designed. Measured insertion losses are below 1 dB in an unprecedented 130 nm bandwidth, limited by the measurement setup, with full 3D finite‐difference time‐domain (FDTD) simulations predicting a bandwidth in excess of 300 nm. Furthermore, the device is well suited to feed fiber‐to‐chip grating couplers, while requiring a footprint ten times smaller than conventional adiabatic tapers

    Subwavelength metamaterial engineering for silicon photonics

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    Waveguides structured at the subwavelength scale frustrate di raction and behave as optical metamaterials with controllable refractive index. These structures have found widespread applications in silicon photonics, ranging from sub-decibel e ciency bre-chip couplers to spectrometers and polarization rotators. Here, we briefly describe the design foundations for sub-wavelength waveguide devices, both in terms of analytic e ective medium approximations, as well as through rigorous Floch-Bloquet mode simulation. We then focus on two novel structures that exemplify the use of subwavelength waveguides: mid-infrared waveguides and ultra-broadband beamsplitters.Universidad de M alaga,Campus de Excelencia Internacional Andalucía Tech. Ministerio de Econom a y Competitividad, Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad (cofi nanciado FEDER), Proyecto TEC2013-46917-C2-1-R, Proyecto TEC2016-80718-

    Estructuras sub-longutud de onda para el diseño de dispositivos en guía dieléctrica

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    Sub-wavelength structures are enabling the design of devices based in dielectric waveguides with unprecedented performance in both the near-infrared and mid-infrared wavelength regions. These devices include fiber-to-chip grating couplers with sub-decibel efficiency, waveguide couplers with bandwidths of several hundred nanometers, and low loss suspended waveguides. Here we will report our progress in the electromagnetic modelling and simulation of sub-wavelength structures, providing at the same time an intuitive vision of their fundamental optical properties. Furthermore, we will address design strategies for several integrated optical devices based on these structures, and present the latest experimental results for structures operating both at near and mid-infrared wavelengths.Universidad de Málaga. Campus de Excelencia Andalucía Tech

    Design of subwavelength grating metamaterial waveguides for communications and sensing applications

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    In this work we will cover some of our recent advances in the design of state-of-the-art silicon photonic devices based on all-dielectric subwavelength grating (SWG) metamaterials. Specifically, we will focus on the design of tilted SWG waveguides, integrated anisotropic SWG lenses, spectral filters based on SWGs and SWG structures for evanescent field sensing.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Subwavelength metamaterial structures for silicon photonics

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    Sub-wavelength periodic metamaterial structures are enabling the design of silicon photonic devices with unprecedented performance in the near infrared band. However, for applications in the promising mid-infrared band it is expected that they acquire even more prominence because for longer wavelengths it is far easier to fabricate structures with a sub- wavelength pitch. Here we report our recent progress in the electromagnetic modeling of sub-wavelength structures, and we will review some of our latest advances in the development of sub-wavelength based devices operating both at near and mid- infrared wavelengths.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Adopting a High-Polyphenolic Diet Is Associated with an Improved Glucose Profile: Prospective Analysis within the PREDIMED-Plus Trial

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    Previous studies suggested that dietary polyphenols could reduce the incidence and complications of type-2 diabetes (T2D); although the evidence is still limited and inconsistent. This work analyzes whether changing to a diet with a higher polyphenolic content is associated with an improved glucose profile. At baseline, and at 1 year of follow-up visits, 5921 participants (mean age 65.0 ± 4.9, 48.2% women) who had overweight/obesity and metabolic syndrome filled out a validated 143-item semi-quantitative food frequency questionnaire (FFQ), from which polyphenol intakes were calculated. Energy-adjusted total polyphenols and subclasses were categorized in tertiles of changes. Linear mixed-effect models with random intercepts (the recruitment centers) were used to assess associations between changes in polyphenol subclasses intake and 1-year plasma glucose or glycosylated hemoglobin (HbA1c) levels. Increments in total polyphenol intake and some classes were inversely associated with better glucose levels and HbA1c after one year of follow-up. These associations were modified when the analyses were run considering diabetes status separately. To our knowledge, this is the first study to assess the relationship between changes in the intake of all polyphenolic groups and T2D-related parameters in a senior population with T2D or at high-risk of developing T2

    XVI International Congress of Control Electronics and Telecommunications: "Techno-scientific considerations for a post-pandemic world intensive in knowledge, innovation and sustainable local development"

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    Este título, sugestivo por los impactos durante la situación de la Covid 19 en el mundo, y que en Colombia lastimosamente han sido muy críticos, permiten asumir la obligada superación de tensiones sociales, políticas, y económicas; pero sobre todo científicas y tecnológicas. Inicialmente, esto supone la existencia de una capacidad de la sociedad colombiana por recuperar su estado inicial después de que haya cesado la perturbación a la que fue sometida por la catastrófica pandemia, y superar ese anterior estado de cosas ya que se encontraban -y aún se encuentran- muchos problemas locales mal resueltos, medianamente resueltos, y muchos sin resolver: es decir, habrá que rediseñar y fortalecer una probada resiliencia social existente - producto del prolongado conflicto social colombiano superado parcialmente por un proceso de paz exitoso - desde la tecnociencia local; como lo indicaba Markus Brunnermeier - economista alemán y catedrático de economía de la Universidad de Princeton- en su libro The Resilient Society…La cuestión no es preveerlo todo sino poder reaccionar…aprender a recuperarse rápido.This title, suggestive of the impacts during the Covid 19 situation in the world, and which have unfortunately been very critical in Colombia, allows us to assume the obligatory overcoming of social, political, and economic tensions; but above all scientific and technological. Initially, this supposes the existence of a capacity of Colombian society to recover its initial state after the disturbance to which it was subjected by the catastrophic pandemic has ceased, and to overcome that previous state of affairs since it was found -and still is find - many local problems poorly resolved, moderately resolved, and many unresolved: that is, an existing social resilience test will have to be redesigned and strengthened - product of the prolonged Colombian social conflict partially overcome by a successful peace process - from local technoscience; As Markus Brunnermeier - German economist and professor of economics at Princeton University - indicates in his book The Resilient Society...The question is not to foresee everything but to be able to react...learn to recover quickly.Bogot
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