Local field intensity in aggregates illuminated by diffuse light: T matrix approach

Area of Science:

• Electromagnetism
• Optics
• Condensed Matter Physics

Background:

• Understanding light interaction with particle aggregates is crucial in various scientific fields.
• Existing methods often struggle with the complexity of diffuse light scattering in heterogeneous media.

Purpose of the Study:

• To derive an analytic expression for local field intensity in particle aggregates under diffuse light.
• To analyze electromagnetic couplings between particles using a novel diffuse light averaging formula.

Main Methods:

• Utilized the T matrix formalism for deriving the analytic expression.
• Employed the recursive centered T matrix algorithm (RCTMA) for numerical calculations.
• Averaged electromagnetic response over all incident plane wave directions and polarizations.

Main Results:

• The diffuse light averaging significantly smooths out intense angular and local field variations.
• Demonstrated reduced complexity in field intensity calculations compared to orientation-fixed methods.
• Successfully analyzed electromagnetic couplings between two isotropic spheres as a function of separation.

Conclusions:

• The derived formalism provides a valuable tool for analyzing electromagnetic couplings in dense random heterogeneous media.
• Diffuse averaging simplifies the complex electromagnetic behavior in media dominated by scalar diffusion.
• This approach offers a more tractable method for studying light propagation in complex particle systems.