Hybrid confinement of optical and mechanical modes in a bullseye optomechanical resonator

Optomechanical cavities have proven to be an exceptional tool to explore fundamental and technological aspects of the interaction between mechanical and optical waves. Such interactions strongly benefit from cavities with large optomechanical coupling, high mechanical and optical quality factors, and mechanical frequencies larger than the optical mode linewidth, the so called resolved sideband limit. Here we demonstrate a novel optomechanical cavity based on a disk with a radial mechanical bandgap. This design confines light and mechanical waves through distinct physical mechanisms which allows for independent control of the mechanical and optical properties. Our device design is not limited by unique material properties and could be easily adapted to allow large optomechanical coupling and high mechanical quality factors with other promising materials. Finally, our demonstration is based on devices fabricated on a commercial silicon photonics facility, demonstrating that our approach can be easily scalable.Comment: 16 pages, 11 figure

Brillouin Optomechanics In Coupled Silicon Microcavities

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The simultaneous control of optical and mechanical waves has enabled a range of fundamental and technological breakthroughs, from the demonstration of ultra-stable frequency reference devices, to the exploration of the quantum-classical boundaries in optomechanical laser-cooling experiments. More recently, such an optomechanical interaction has been observed in integrated nano-waveguides and microcavities in the Brillouin regime, where short-wavelength mechanical modes scatter light at several GHz. Here we engineer coupled optical microcavities to enable a low threshold excitation of mechanical travelling-wave modes through backward stimulated Brillouin scattering. Exploring the backward scattering we propose silicon microcavity designs based on laterally coupled single and double-layer cavities, the proposed structures enable optomechanical coupling with very high frequency modes (11 to 25 GHz) and large optomechanical coupling rates (g(0)/2 pi) from 50 kHz to 90 kHz.7Sao Paulo State Research Foundation (FAPESP) [2012/17765-7, 2012/17610-3]National Counsel of Technological and Scientific Development (CNPQ)Coordination for the Improvement of Higher Education Personnel (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Utilización del polimorfismo del ADN de cloroplastos para definir regiones de procedencia materna en los robles blancos de la Península Ibérica

We present here the results obtained after the study of 156 oak populations collected along the Iberian Peninsula. Six oak species were present in the sample: Quercus canariensis, Q. faginea, Q. humilis, Q. pyrenaica, Q. robur and Q. petraea. Five trees from each population were analyzed with four cpDNA specific pairs of primers that allowed the distinction of 13 haplotypes. In populations with several species, all of them shared the same haplotype, and none of the common haplotypes was restricted to a single species. Analysis of molecular variance in the data revealed a strong genetic structure. Maternal provenance regions were defined that maximize the among groups variance and minimize the among populations/within groups variance. The distribution of the haplotypes suggests the existence of several distinct refugia, not restricted to the South of the Peninsula.En este trabajo se presentan los resultados obtenidos tras el estudio de 156 poblaciones de robles a lo largo de la Península Ibérica. Los robles estudiados pertenecen a seis especies: Quercus canariensis, Q. faginea, Q. humilis, Q. pyrenaica, Q. robur y Q. petraea. Se analizaron cinco árboles de cada población con cuatro pares de cebadores específicos de cpADN, lo que permitió distinguir un total de 13 haplotipos. En las poblaciones en las que había varias especies, generalmente todas mostraron el mismo haplotipo; y ninguno de los haplotipos comunes representa a una sola especie. El análisis de la varianza molecular (AMOVA) ha revelado una fuerte estructura genética. Las regiones de procedencia materna se definieron de tal manera que se maximizara la varianza entre grupos y minimizara la varianza entre poblaciones dentro de grupos. Por último, la distribución de haplotipos sugiere la existencia de diversos refugios glaciares no restringidos únicamente al sur de la Península

Efficient anchor loss suppression in coupled near-field optomechanical resonators

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQElastic dissipation through radiation towards the substrate is a major loss channel in micro-and nanomechanical resonators. Engineering the coupling of these resonators with optical cavities further complicates and constrains the design of low-loss optomechanical devices. In this work we rely on the coherent cancellation of mechanical radiation to demonstrate material and surface absorption limited silicon near-field optomechanical resonators oscillating at tens of MHz. The effectiveness of our dissipation suppression scheme is investigated at room and cryogenic temperatures. While at room temperature we can reach a maximum quality factor of 7.61k (fQ-product of the order of 10(11) Hz), at 22 K the quality factor increases to 37k, resulting in a fQ-product of 2 x 10(12) Hz.25253134731361FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ2008/57857-22012/17610-32012/17765-7153044/2013-

Third-harmonic generation in silica wedge resonators

Whispering-gallery-mode microcavities are known to have high optical quality factor, making them suitable for nonlinear optical interactions. Here, third-harmonic generation is observed using a relatively small radius wedge silicon oxide optical microcavity. The small radii wedge microdisks can be dispersion-tailored to obtain either normal or anomalous group velocity dispersion. In our case, we operate in the normal dispersion regime preventing frequency comb generation by suppressing infrared cascading four-wave mixing. This allows for a clean third harmonic generation at phase-matched visible optical modes. Tunability of the third-harmonic emission is obtained due to a combination of the thermo-optical and Kerr effects. An additional thermal control of the phase matching condition allows for optimizing third-harmonic generation, and agreement between this process and couple-mode theory is demonstrated.Comment: 6 pages, 6 figure

Brillouin scattering self-cancellation

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORThe interaction between light and acoustic phonons is strongly modified in sub-wavelength confinement, and has led to the demonstration and control of Brillouin scattering in photonic structures such as nano-scale optical waveguides and cavities. Besides the small optical mode volume, two physical mechanisms come into play simultaneously: a volume effect caused by the strain-induced refractive index perturbation (known as photo-elasticity), and a surface effect caused by the shift of the optical boundaries due to mechanical vibrations. As a result, proper material and structure engineering allows one to control each contribution individually. Here, we experimentally demonstrate the perfect cancellation of Brillouin scattering arising from Rayleigh acoustic waves by engineering a silica nanowire with exactly opposing photo-elastic and moving-boundary effects. This demonstration provides clear experimental evidence that the interplay between the two mechanisms is a promising tool to precisely control the photon-phonon interaction, enhancing or suppressing it.The interaction between light and acoustic phonons is strongly modified in sub-wavelength confinement, and has led to the demonstration and control of Brillouin scattering in photonic structures such as nano-scale optical waveguides and cavities. Besides the small optical mode volume, two physical mechanisms come into play simultaneously: a volume effect caused by the strain-induced refractive index perturbation (known as photo-elasticity), and a surface effect caused by the shift of the optical boundaries due to mechanical vibrations. As a result, proper material and structure engineering allows one to control each contribution individually. Here, we experimentally demonstrate the perfect cancellation of Brillouin scattering arising from Rayleigh acoustic waves by engineering a silica nanowire with exactly opposing photo-elastic and moving-boundary effects. This demonstration provides clear experimental evidence that the interplay between the two mechanisms is a promising tool to precisely control the photon-phonon interaction, enhancing or suppressing it.718FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR08/57857-2, 2012/17610-3, 2012/17765-7, 2013/20180-3574017/2008-9Sem informaçã

CONOCIMIENTOS DE LOS ESTILOS DE VIDA DE LOS PACIENTES CON DIABETES MELLITUS TIPO II ASISTIDOS EN EL HOSPITAL SAN JUAN DE DIOS DE PAMPLONA (HSJD). PARA GENERAR UN PLAN DE INTERVENCION EDUCATIVO EN ENFERMERÍA

Con el fin de lograr realizar un aporte al personal de salud acerca del fortalecimiento en la educación de los estilos de vida que deben seguir los pacientes con Diabetes Mellitus tipo II para disminuir las complicaciones e ingresos por la enfermedad. Objetivo: Determinar los estilos de vida de los pacientes que presentan Diabetes Mellitus tipo II. Con el fin de proponer un plan de intervención educativo para el personal de enfermería Metodología: Estudio descriptivo, cuantitativo de corte transversal, con la aplicación del instrumento IMEVID, tabular los datos y con base en esto se proponer un plan educativo como derrotero de acción de enfermería. Conclusión: Basado en el conocimiento de los estilos de vida de los pacientes se con Diabetes Mellitus tipo II Se genero un plan de intervenciones de enfermería con el que se pretende vincular al paciente por medio de la educación de estilos de vida

Relationship between Serum Concentration of Uric Acid and Insulin Secretion among Adults with Type 2 Diabetes Mellitus

To determine the relationship between serum concentrations of uric acid and insulin secretion with hyperglycaemic clamp technique among adults with type 2 diabetes mellitus (DM2) without hyperuricemia, we carried out a cross-sectional study on 45 patients of both gender. We observed correlation between uric acid with male gender r = 0.710 (P = 0.001). Also correlation between uric acid and total insulin secretion was positive r = 0.295 (P = 0.049). As well as a positive correlation adjusted for body mass index was demonstrated for the first, second, and total phases of insulin secretion, respectively, r = 0.438 (P = 0.022), r = 0.433 (P = 0.022), and r = 0.439 (P = 0.024). Serum concentration of uric acid showed a positive relationship with the total phase of insulin secretion; even in states prior to hyperuricemia, uric acid can play an important role in the function of the beta cell in patients with DM2