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A fast algorithm for the evaluation of acoustic fields produced by given source distributions is developed with the aim of accelerating iterative boundary element method (BEM) solvers. The algorithm is based on field smoothing by phase and amplitude compensation, which allows for sampling of the fields radiated by finite-size source distributions over(More)
A novel device, formed by a widely spaced periodic array of defects in a photonic bandgap crystal, is studied with the goal of designing a waveguide with a prescribed narrow bandwidth. Tunneling of radiation between the defect sites allows wave propagation along the line of the defects. An analytical study based on the weakly coupled cavity model is(More)
We derive an exact spectral representation for the Green's function of Maxwell equations in a two-dimensional homogeneous and rotating environment. The formulation is developed in the medium (noninertial) rest frame, and it represents the response to a point source, where both the source and observation points rotate together with the medium. The closed(More)
We present an algorithm for reconstructing a sample surface potential from its Kelvin probe force microscopy (KPFM) image. The measured KPFM image is a weighted average of the surface potential underneath the tip apex due to the long-range electrostatic forces. We model the KPFM measurement by a linear shift-invariant system where the impulse response is(More)
A fast multilevel direct solver for electromagnetic scattering from quasi-planar objects is presented. The solver relies on the compression of the off-diagonal blocks in the impedance matrix, which describe interactions between distinct domains. The compression is performed in a number of steps. First, the scatterer is decomposed into sub-domains using a(More)
Photonic crystal microcavities, formed by local defects within an otherwise perfectly periodic structure, can be used as narrowband optical resonators and filters. The coupled-cavity waveguide (CCW) is a linear array of equally spaced identical microcavities. Tunneling of light between microcavities forms a guiding effect, with a central frequency and(More)
A fast non-iterative algorithm for the solution of large 3-D acoustic scattering problems is presented. The proposed approach can be used in conjunction with the conventional boundary element discretization of the integral equations of acoustic scattering. The algorithm involves domain decomposition and uses the nonuniform grid (NG) approach for the initial(More)
A novel algorithm for fast computation of tomographic image projections is presented. The method comprises a decomposition of an image into subimages followed by an aggregation of projections computed for the subimages. The multilevel domain decomposition algorithm is formulated as a recursive procedure. The computational cost of the proposed algorithm is(More)
We demonstrate wide-angle, broadband, and efficient reflection holography by utilizing coupled dipole-patch nanoantenna cells to impose an arbitrary phase profile on the reflected light. High-fidelity images were projected at angles of 45 and 20° with respect to the impinging light with efficiencies ranging between 40-50% over an optical bandwidth exceeding(More)