A one-dimensional photonic crystal sustaining Bloch Surface Waves (BSWs) is used as a platform for two-dimensional integrated optics. The dielectric platform shows low loss, long propagation distance and high surface field enhancement. In order to study the potential of the platform for future photonic chips, polymer ultra-thin prisms and gratings (~100 nm) are engineered on the top of the plat...

Wideband suppression of zero order and relevant strongly asymmetric transmission can be obtained in photonic crystal gratings that are made of linear isotropic materials and show the broken structural (axial) symmetry, even if zero diffraction order may be coupled to a Floquet-Bloch (FB) wave at the incidence and exit interfaces. The studied mechanism requires that the peculiar diffractions at ...

We construct a numerical scheme based on the Liouville equation of geometric optics coupled with the Geometric Theory of Diffraction (GTD) to simulate the high frequency linear waves diffracted by a half plane. We first introduce a condition, based on the GTD theory, at the vertex of the half plane to account for the diffractions, and then build in this condition as well as the reflection bound...

Exploiting the fine structure of strongly scattered surface waves could provide a wealth of new information in seismology, ultrasonics, acoustics and other fields that study wave propagation in highly heterogeneous media. Toward this end, we have made laboratory measurements of ultrasonic waves propagating in disordered media. Spectral-element simulations of these models provide us with a power...

We present a fast algorithm to perform sound propagation in complex 3D scenes. Our approach computes propagation paths from each source to the listener by taking into account specular reflections and higher-order edge diffractions around finite edges in the scene. We use the well known Biot-Tolstoy-Medwin diffraction model along with efficient algorithms for region-based visibility to cull away...

We present an auralization algorithm for interactive virtual environments with dynamic objects, sources, and listener. Our approach uses a modified image source method that computes propagation paths combining direct transmission, specular reflections, and edge diffractions up to a specified order. We use a novel multi-view raycasting algorithm for parallel computation of image sources on GPUs....

The femtosecond-laser-writing technique provides a flexible method for fabrication of nonlinear photonic crystals in three dimensions, providing structures that enable efficient complex wave interactions and modulation applications including holography, beam shaping, waveguide-integrated wavelength conversion. However, the tightly focused laser pulse inevitably causes structural modification th...

Resumo Este artigo analisa como a narrativa de Namíbia, não!, texto teatral do ator e diretor baiano Aldri Anunciação, elabora um universo distópico em que o cruzamento temporalidades expõe contradições passado, amplia percepção sobre violência racial presente realiza projeções futuro hostilidade as interdições se materializam no espaço. Para isso, utiliza contribuições intelectuais Grada Kilom...

soil samples were collected from seven sites in and around the metropolitan area of mexicocity. the locations were chosen as possible sources of fugitive dusts which contribute to suspended particulate matter in the atmosphere of mexico city. x-ray fluorescence (xrf) was used to determine the concentrations of several major elements (si, k, ca, ti, mn, and fe), as well as of other trace element...