Publications by authors named "Sacha Verweij"

We show that iterative solution of Maxwell's equations using the finite-difference frequency-domain method can be significantly accelerated by using a Schur complement domain decomposition method. We account for the improvement by analyzing the spectral properties of the linear systems resulting from the use of the domain decomposition method.

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We present a Schur complement domain decomposition method that can significantly accelerate simulation of ensembles of locally differing optical structures. We apply the method to design a multi-spatial-mode photonic crystal waveguide splitter that exhibits high transmission and preservation of modal content, showing design acceleration by more than a factor of 20.

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A system incorporating automated 3-D ultrasound and digital X-ray tomosynthesis is being developed for improved breast lesion detection and characterization. The goal of this work is to develop and test candidates for a dual-modality mesh compression paddle. A Computerized Imaging Reference Systems (Norfork, VA, USA) ultrasound phantom with tilted low-contrast cylindrical objects was used.

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A self-contained source characterization method for commercial ultrasound probes in transmission acoustic inverse scattering is derived and experimentally tested. The method is based on modified scattered field volume integral equations that are linked to the source-scattering transducer model. The source-scattering parameters are estimated via pair-wise transducer measurements and the nonlinear inversion of an acoustic propagation model that is derived.

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