Ultimate Absorption in Light Scattering by a Finite Obstacle

Area of Science:

• Optics and Photonics
• Electromagnetism
• Scattering Theory

Background:

• Light absorption by particles is crucial in various fields, including atmospheric optics and material science.
• Previous studies focused on specific particle shapes and optical properties, lacking a universal absorption limit.
• Understanding absorption limits is key to designing materials with tailored optical responses.

Purpose of the Study:

• To rigorously prove and calculate the ultimate upper limit for light absorption by any partial mode.
• To establish a universal absorption limit independent of scatterer characteristics.
• To generalize findings from spherical particles to arbitrary finite obstacles.

Main Methods:

• Analysis of fundamental light scattering properties under plane, linearly polarized wave illumination.
• Derivation of the absorption limit based on incident light wave number and partial mode multipolarity.
• Generalization of results for spherical particles to arbitrary finite scatterers and various incident wave conditions.

Main Results:

• An explicit calculation of the ultimate upper limit for partial mode light absorption.
• Demonstration that this limit is a universal function of incident light properties and mode multipolarity only.
• Proof that maximal partial absorption cross-section is bounded by values for homogeneous spheres (3D) and cylinders (2D).

Conclusions:

• A fundamental, universal upper limit for light absorption by partial modes has been rigorously established.
• This limit provides a new theoretical benchmark for light absorption in diverse scattering scenarios.
• The findings have implications for optimizing light absorption in nanophotonics and metamaterial design.