Light scattering by randomly oriented bispheres.

Area of Science:

• Electromagnetic scattering
• Optical properties of particles
• Computational physics

Background:

• Understanding light scattering by non-spherical particles is crucial in various fields.
• Previous studies often simplified particle shapes, limiting accuracy.
• Bispheres offer a more complex yet realistic model for certain particle aggregates.

Purpose of the Study:

• To analytically compute the Stokes scattering matrix for randomly oriented bispheres using the T-matrix approach.
• To compare the scattering properties of bispheres with those of spheroids and spheres.
• To investigate the role of cooperative scattering in the depolarization capabilities of bispheres.

Main Methods:

• Analytical computation of the Stokes scattering matrix.
• Application of the T-matrix method.
• Modeling randomly oriented bispheres (touching and separated components).
• Comparison with volume-equivalent prolate spheroids and spheres.

Main Results:

• The T-matrix approach successfully computed the Stokes scattering matrix for bispheres.
• Bispheres with touching components exhibited more efficient depolarization than spheroids in the back-scattering direction.
• Cooperative (multiple-scattering) effects were identified as the cause for enhanced depolarization in bispheres.

Conclusions:

• The T-matrix method is effective for studying light scattering by complex particle shapes like bispheres.
• Bispheres can be more significant depolarizers than simpler shapes under certain conditions.
• Cooperative scattering plays a key role in the optical properties of particle aggregates.