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Discrete-dipole approximation for periodic targets: theory and tests.
Bruce T Draine1, Piotr J Flatau
1Princeton University Observatory, Princeton, New Jersey 08544-1001, USA. draine@astro.princeton.edu
Summary
The discrete-dipole approximation (DDA) method accurately calculates light scattering for periodic targets. This study extends DDA to periodic structures and validates it for infinite cylinders and slabs.
Area of Science:
- Electromagnetics
- Computational physics
- Optics
Background:
- The discrete-dipole approximation (DDA) is widely used for light scattering calculations of small particles.
- Extending DDA to periodic structures is crucial for modeling realistic materials and surfaces.
Purpose of the Study:
- To generalize the scattering amplitude and Mueller matrices for singly and doubly periodic targets.
- To demonstrate the calculation of these matrices using the DDA method.
- To present a method for obtaining internal and near-target fields.
Main Methods:
- Generalization of scattering amplitude and Mueller matrices for periodic targets.
- Application of the discrete-dipole approximation (DDA) using the DDSCAT code.
- Validation against exact solutions for infinite cylinders and slabs.
Main Results:
- Accurate calculation of scattering matrices for periodic targets using DDA.
- Demonstrated accuracy of DDSCAT code by comparison with exact solutions.
- Successful retrieval of fields within and near infinite slabs.
Conclusions:
- DDA is a versatile method for calculating scattering by periodic structures.
- The generalized matrices and methods provide accurate tools for electromagnetic simulations.
- The study validates DDA for complex periodic geometries.
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