Search

We present large-scale computations of currents induced in the human body, arising from an external low-frequency magnetic-field source. The calculations are performed using the Ex-SPFD approach; an extension of the classical SPFD approach, that can handle arbitrarily shaped magnetic-field sources and highly conductive material inside the computational domain. In order to sufficiently resolve even small organs such as the eye, very fine spatial resolution is needed. Such fine resolution results in very large systems of equations. Problems consisting of up to 200 millions of unknowns are presented. Index Terms--Biological effects of electromagnetic radiation, eddy currents, finite difference methods.

The calculation of current densities in voxel-based high-resolution anatomy models allows insight in the current distribution inside the human body. The geometric complexity of the human body requires a very high resolution in order to properly resolve small organs. We present a local grid refinement scheme for low-frequency current calculations, allowing to finely resolve areas of particular interest. Using a Lagrange-multiplier approach, the whole model including the fine and coarse grid domains can be computed with only one solution of an algebraic system of equations. The presented approach is validated and tested on numerical examples. Index Terms--Biological effects of electromagnetic radiation, electrodynamics, finite integration technique, iterative methods.

Picosecond-resolved measurements of vertical-cavity surface-emitting laser (VCSEL) emissions are investigated and discussed.

We present two-dimensional (2-D) spatially and picosecond-resolved measurements of vertical-cavity surface-emitting lasers' emission, unveiling their rich dynamics, manifesting itself in temporal changes of the modal, polarization, spectral, and spatial characteristics. The measurements providing insight into the repetitive part of the dynamics were performed with a newly developed experimental technique. In addition, we present the first 2-D, spatially resolved, single-shot event measurements which provide a full complementary picture of the dynamical behavior. The experimental results are analyzed and discussed with respect to spatio-spectral interaction mechanisms of carriers and photons, explaining the observed behavior. [ABSTRACT FROM AUTHOR]