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Validity criteria of the discrete dipole approximation
Evgenij Zubko1, Dmitry Petrov, Yevgen Grynko
1Graduate School of Science, Tohoku University, Aoba, Aramakiaza, Aoba-ku, Sendai 980-8578, Japan. ezubko@rambler.ru
Applied Optics
|March 12, 2010
Summary
The discrete dipole approximation (DDA) has less strict size restrictions for studying light scattering from irregularly shaped particles than previously thought. These findings expand DDA
Area of Science:
- Computational physics
- Optics
- Materials science
Background:
- The discrete dipole approximation (DDA) is widely used for light scattering simulations.
- Existing DDA applications face restrictions on cell size for dielectric and conductive particles.
Purpose of the Study:
- To re-evaluate the accepted restrictions on DDA cell size for irregularly shaped particles.
- To investigate the impact of larger cell sizes on DDA accuracy for dielectric and conductive particles.
Main Methods:
- Numerical simulations applying DDA to irregularly shaped particles.
- Analysis of DDA accuracy under varying cell sizes and particle properties.
- Comparison of DDA results with theoretical expectations for electromagnetic field evolution.
Main Results:
- DDA provides accurate results for irregularly shaped particles even at kd|m|=1.
- Using larger cells in DDA can mimic the effect of surface roughness.
- Inaccurate skin layer description for conductive particles has a minor impact on scattering properties.
Conclusions:
- DDA restrictions are less stringent for irregularly shaped particles than commonly accepted.
- The DDA can be applied more broadly, especially for modeling surface roughness effects.
- Maxwell's equations are not violated, and scattering properties are only slightly affected by skin layer approximations.
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