Bricked and evanescently-coupled topologies: expanding the portfolio of subwavelength metamaterial silicon photonic devices

We present two novel topologies of subwavelength grating (SWG) waveguides: the bricked-SWG and the evanescently-coupled-SWG. The bricked topology enables accurate control of waveguide anisotropy while maintaining the index and dispersion engineering advantage intrinsic to SWG waveguides. The evanescently-coupled-SWG allows unprecedented control of the strength of the modal perturbation in waveguide Bragg gratings and nanophotonic antennas. Both topologies leverage a Manhattan-like pattern, with pixel sizes compatible with deep-uv lithography. Our recent results will be discussed, focusing on polarization-independent multimode interference couplers for the O and C bands and a millimeter-long narrow-beam steerable optical antenna array with angular divergence of only 1.8º×0.2º.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Integrated metamaterial surface-emitting antenna for beam steering applications

Integrated optical antennas are relevant devices for the development of next-generation LIDAR systems. Here we experimentally demonstrate a new topology to implement long antennas in silicon-on-insulator platform. The designed 2-millimeter-long antenna presents a measured far-field beam divergence of 0.1° and a wavelength sensitivity of 0.13°/nm.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. HTSN Challenge Program at the NRC of Canada; Junta de Andalucía (P18-RT-1453, P18-RT-793, UMA18-FEDERJA-219); Ministerio de Ciencia, Innovación y Universidades (FPU16/03401, PID2019-106747RBI00)

Recent progress in subwavelength grating metamaterial engineered silicon photonic devices.

In this talk we present our recent advances in SWG metamaterial engineering. We will show a 1D-optical phased array composed of 112 evanescent-coupled surface emitting antennas with a length of 1.5 mm and fed by a compact distributed Bragg deflector. The measurements demonstrate a wavelength-steerable collimated beam with a far-field angular divergence of 1.8o × 0.2o. Experimental results of a bricked SWG 2×2 MMI coupler are also shown, achieving polarization agnostic performance in the 1500nm to 1560nm wavelength range. Both devices were fabricated on a standard 220-nm SOI platform using a single full-etch step process, with a minimum feature size of 80 nm, and thus compatible with immersion deep-UV lithography.This work was supported by the High Throughput and Secure Networks Challenge Program at the National Research Council of Canada (HTSN-209, 175363-HTSN 210); Ministerio de Ciencia, Innovación y Universidades (PID2019-106747RB-I00); Ministerio de Universidades (FPU19/02408, FPU20/03487); Junta de Andalucía (P18-RT-1453); FEDER Andalucía (UMA20-FEDERJA-158); Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Subwavelength-engineered metamaterial devices for integrated photonics

The engineering of subwavelength grating metamaterials has become an essential design strategy in silicon photonics. The lithographic segmentation of integrated waveguides at the subwavelength scale enables the synthesis of on-chip metamaterials and provides control over optical properties such as mode delocalization, wavelength dispersion, and anisotropy. At the near-infrared wavelengths of the 1.55-μm telecom band, a range of subwavelength-based devices with unprecedented performance has been demonstrated, including couplers, filters, and polarization-handling structures. In this invited paper, we review the foundations of anisotropic subwavelength grating metamaterials and discuss our latest advances in five new subwavelength-enhanced devices: a millimeter-long optical antenna that is evanescently coupled to diffractive lateral segments, thereby achieving a record far-field beam width of 0.1º in silicon; a multi-line integrated Bragg filter also using lateral loading segments, which produces 20 non-uniformly spaced spectral notches with a 3-dB linewidth as low as 210 pm; a low-loss curved wavelength demultiplexer; a segmented multi-mode interference coupler based on novel bricked subwavelength gratings, yielding a 1-dB bandwidth exceeding 140 nm; and a suspended waveguide platform with low propagation loss at mid-infrared wavelengths.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe