Minimum forward light scattering by silicon nanopillars

[Proceeding of]: META'16: The 7th International Conference on Metamaterials, Photonic Crystals and Plasmonics: July 25-28, 2016, Málaga, Spain.In this paper, we demonstrate that for silicon nanopillars an optimum aspect ratio can be found, at which the overlapped electric and magnetic dipole resonances provide an optimized minimum forward scattering. This optimum shape depends on the aspect ratio, wavelength and refractive index of the surrounding medium. We work in the frame of numerical simulations based on Maxwell equations solved by finite element method. These results are promising for design and create novel flat optical devices.This work has been supported by Ministerio de Economía y Competitividad of Spain (grant no. TEC2013-50138-EXP & TEC2013-47342-C2-2-R) and the R&D Program SINFOTON S2013/MIT-2790 of the Comunidad de Madrid.Publicad

Control of the Light Interaction in a Semiconductor Nanoparticle Dimer Through Scattering Directionality

Dimers of nanoparticles are very interesting for several devices due to the possibility of obtaining intense light concentrations in the gap between them. A dynamic control of this interaction to obtain either the maximum or minimum light through interferential effects could be also relevant for a multitude of devices such as chemical sensors or all-optical devices for interchip/intrachip communications. Semiconductor nanoparticles satisfying Kerker conditions present an anisotropic scattering distribution with a minimum in either the forward or the backward direction and prominent scattering in the contrary direction. The reduction or enhancement of the electromagnetic field in a certain direction can minimize or maximize the interaction with neighboring nanoparticles. In this paper, we consider a dimer of nanoparticles such that each component satisfies each one of the Kerker conditions. Depending on the arrangement of the nanoparticles with respect to the impinging light direction, we can produce a minimum or a maximum of the electric field between them, reducing or maximizing the interferential effects. The strong dependence of the directional conditions with external conditions, such as the incident wavelength, can be used to dynamically control the light concentration in the gap.This work was supported in part by the Ministerio de Economía y Competitividad of Spain under Grant TEC2013-50138-EXP and Grant TEC2013-47342-C2-2-R, by the RD Program of the Comunidad de Madrid under Grant SINFOTON S2013/MIT-2790, and by COST Action IC120

Towards the polarization control of the directional scattering of semiconductor nanodisks

[Proceeding of]: META'16: The 7th International Conference on Metamaterials, Photonic Crystals and Plasmonics: July 25-28, 2016, Málaga, Spain.In this work we analyze the sensitivity of the directional scattering conditions in semiconductor nanodisks with the polarization of the incident light. The possibility to reach or not this directional scattering as a function of the polarization of the incident beam could be very interesting for the design of new all-optical devices for optical communications and computing.This work has been supported by Ministerio de Economía y Competitividad of Spain (grant no. TEC2013-50138-EXP) and the R&D Program SINFOTON S2013/MIT-2790 of the Comunidad de Madrid.Publicad

Search for the Higgs boson decays H → ee and H → eμ in pp collisions at √s = 13 TeV with the ATLAS detector

Artículo escrito por un elevado número de autores, sólo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiera, y los autores pertenecientes a la UAMSearches for the Higgs boson decays H→eeand H→eμare performed using data corresponding to an integrated luminosity of 139 fb−1collected with the ATLAS detector in ppcollisions at √s=13 TeV at the LHC. No significant signals are observed, in agreement with the Standard Model expectation. For a Higgs boson mass of 125 GeV, the observed (expected) upper limit at the 95% confidence level on the branching fraction β(H→ee)is 3.6 ×10−4(3.5 ×10−4) and on β(H→eμ)is 6.2 ×10−5(5.9 ×10−5). These results represent improvements by factors of about five and six on the previous best limits on β(H→ee)and β(H→eμ)respectivelyWe acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF and DNSRC, Denmark; IN2P3-CNRS, CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, HGF, and MPG, Germany; GSRT, Greece; RGC, Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MNiSW and NCN, Poland; FCT, Portugal; MNE/IFA, Romania; MES of Russia and NRC KI, Russian Federation; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZŠ, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, United States of America. In addition, individual groups and members have received support from BCKDF, CANARIE, CRC and Compute Canada, Canada; COST, ERC, ERDF, Horizon 2020, and Marie Skłodowska-Curie Actions, European Union; Investissements d' Avenir Labex and Idex, ANR, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF, Greece; BSF-NSF and GIF, Israel; CERCA Programme Generalitat de Catalunya, Spain; The Royal Society and Leverhulme Trust, United Kingdo

Photonic fractional Fourier transformer with a single dispersive device

In this work we used the temporal analog of spatial Fresnel diffraction to design a temporal fractional Fourier transformer with a single dispersive device, in this way avoiding the use of quadratic phase modulators. We demonstrate that a single dispersive passive device inherently provides the fractional Fourier transform of an incident optical pulse. The relationships linking the fractional Fourier transform order and scaling factor with the dispersion parameters are derived. We first provide some numerical results in order to prove the validity of our proposal, using a fiber Bragg grating as the dispersive device. Next, we experimentally demonstrate the feasibility of this proposal by using a spool of a standard optical fiber as the dispersive device.Centro de Investigaciones Óptica

System Virtualization Tools for Software Development

The configuration complexity of preproduction sites coupled with access-control mechanisms often impede the software development life cycle. Virtualization is a cost-effective way to remove such barriers and provide a test environment similar to the production site, reducing the burden in IT administrators. An Eclipse-based virtualization tool framework can offer developers a personal runtime environment for launching and testing their applications. The authors have followed a model-driven architecture (MDA) approach that integrates best-of-breed virtualization technologies, such as Xen and VDE.ITECBAN is an IT innovation project partially funded by CENIT (a Spanish public R&D program). We're grateful to MITYC (Ministerio de Industria, Turismo y Comercio) and CDTI (Centro para el Desarrollo Tecnológico e Industrial) for supporting ITECBAN through CENIT

All Polarization-maintaining Passively Mode-locked Ytterbium-doped Fiber Lasers, Behavior under Two Different Cavity Configurations

In this work, we review our recent investigations on the behavior of a polarization-maintaining passively mode-locked ytterbium-doped laser in two different cavity configurations, namely: fiber-ring (FR) and Fabry-Perot (FP). Opposed to standard configurations that rely on the use of strong filtering within the cavity by including an ad hoc component with this purpose, here the filtering action is solely performed by the spectral overlapping of the different components within the fiber lasers. We found that the lack of a specific filter within the cavity does not deteriorate the performance as compared with previous works. We also report the changes in the output light pulses when the net dispersion of the cavity was varied. Additionally, different lengths of an ad hoc anomalous polarization-maintaining (PM) photonic crystal fiber (PCF) were used as intracavity dispersion compensator, to shift the operation of the laser from net-normal to the net-anomalous regime. The shortest output light pulses [6 ps (FR) and 8 ps (FP)] were obtained when the net-cavity dispersion approached zero. Since the obtained light pulses were far to be transform-limited, we also discuss the possibility of out-of-cavity recompression by using the same PM-PCF mentioned above. After recompression, pulse widths of 3 ps were obtained, limited by the available length of PM PCF

Studying light concentration in a dimer of semiconductor nanoparticles for all-optical devices

[Proceeding of]: META'16: The 7th International Conference on Metamaterials, Photonic Crystals and Plasmonics: July 25-28, 2016, Málaga, Spain.Scattering by subwavelength dielectric nanospheres can have interesting directionaleffects in the case of accomplishing Kerker's conditions. We have taken advantage of theseconditions to design a dimer of semiconductor nanoparticles where an important contrast can beachieved in their gap, due to the directionality and the interferential interaction of the scatteredfields.This work has been supported by Ministerio de Economía y Competitividad of Spain (grant no. TEC2013-50138-EXP) and the R&D Program SINFOTON S2013/MIT-2790 of the Comunidad de Madrid.Publicad

Low-repetition-rate all-polarization maintaining thulium-doped passively modelocked fiber laser

We have developed a passively mode-locked, all-polarization maintaining, low-repetition-rate thulium-doped fiber laser (PM TDFL) emitting at 1951 nm and pumped by an erbium-ytterbium-doped all-fiber laser at 1561 nm. The PM TDFL was developed with a 44.67 m long polarization-maintaining all-fiber resonator Fabry-Perot using a semiconductor saturable absorber mirror at one end and a highly reflective fiber Bragg grating at the other. In this way, transform-limited low-repetition-rate light pulses at 2.3 MHz were generated, with each light pulse having a temporal width of 81 ps, and a spectral width of 50 pm. We have also compared the performance of this laser with a shortened version of this cavity, 6.25 m long, emitting at 15.6 MHz