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

Agricultura sem fogo na Amazônia Oriental: formiga como indicador agroecológico.

Edição dos Anais do XVIII Simpósio de Mirmecologia, São Paulo, 2007

Problema de contratación de carretilleros para un almacén de productos manufacturados

En este trabajo se analiza un problema planteado recientemente a sus autores por una empresa fabricante de componentes de automóviles. Dicha empresa almacena sus productos manufacturados hasta que los clientes (compradores) pasan a recogerlos. Los clientes solicitan sus productos con una frecuencia conocida. Se trata de determinar, en función de dichas frecuencias, en qué fechas y a qué horas o slots han de pasar los clientes a recoger sus pedidos. Fijado el horizonte temporal objeto de estudio, el objetivo para la empresa es minimizar en ese conjunto de días, el número de carretilleros necesarios para cargar los pedidos en los camiones de los clientes. El número de carretilleros diarios viene determinado por el slot más ocupado. En este problema se han de tomar decisiones a dos niveles: elaboración del calendario de entrega para cada uno de los pedidos, y asignación diaria de pedidos a slots. No se ha encontrado en la literatura ningún trabajo que estudie o pueda ajustarse a este problema. Se diseñan y analizan 3 sencillos Metaheurísticos: uno sigue un proceso de Búsqueda Tabú básico, otro es un procedimiento de Búsqueda en Entorno Variable y el tercero es un Algoritmo Evolutivo. Se realizan pruebas con instancias ficticias y por último se resulven las instancias reales planteadas a los autores de este trabajo

Brillouin optomechanics in nanophotonic structures

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORThe interaction between light and mesoscopic mechanical degrees of freedom has been investigated under various perspectives, from spectroscopy in condensed matter, optical tweezer particle trapping, and long-haul optical fiber communication system penalties to gravitational-wave detector noise. In the context of integrated photonics, two topics with dissimilar origins-cavity optomechanics and guided wave Brillouin scattering-are rooted in the manipulation and control of the energy exchange between trapped light and mechanical modes. In this tutorial, we explore the impact of optical and mechanical subwavelength confinement on the interaction among these waves, coined as Brillouin optomechanics. At this spatial scale, optical and mechanical fields are fully vectorial and the common intuition that more intense fields lead to stronger interaction may fail. Here, we provide a thorough discussion on how the two major physical effects responsible for the Brillouin interaction-photoelastic and moving-boundary effects-interplay to foster exciting possibilities in this field. In order to stimulate beginners into this growing research field, this tutorial is accompanied by all the discussed simulation material based on a widespread commercial finite-element solver.47129FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIOR08/57857-212/17765-712/17610-313/20180-318/15577-518/15580-6574017/2008-900

Fractura de quinta vértebra lumbar : nueva técnica de reducción

En este trabajo pretendemos describir una técnica de fijación externa, con la que se reduce e inmoviliza una fractura en la quinta vertebral lumbar. Usamos un fijador externo tipo II doble de Meynar.In this essay we want to describe a method of external fixation by which you can fixate and inmobilize afracture in the 5th lumbar vertebrae. We use the double external fixators type II of Meynar

Aportes al diagnóstico ecográfico : 17 casos

En este trabajo se relacionan diecisiete casos, con los cuales queremos mostrar las grandes posibilidades de la ecografía como medio de diagnóstico, en las distintas patologías que en él se citan.In this work we find seventeen cases correlated, with which we want to show the great diagnostic possibilities of the echography as well as the source of information it proves to be for the different pathologies mentioned