Dual Synchronization Effects in Light Scattering by Spherical Particle Systems

Abstract: We report the discovery of a novel and fundamental dual synchronization relationship between the scattering efficiency (Q${\text{sca}}$) and a specifically formulated angular distribution complexity parameter ($\widetilde{C}{\text{p}}$) in spherical particle systems. Through extensive numerical simulations using the rigorous Multiple Sphere T-Matrix (MSTM) method, we found that Q${\text{sca}}$ exhibits a strong positive correlation with (1-$\widetilde{C}{\text{p}}$) when the real part of the refractive index is varied, while it synchronizes strongly and positively with $\widetilde{C}{\text{p}}$ when the imaginary part is varied. Our analysis reveals that this duality arises from the distinct ways the real and imaginary parts of the refractive index \textbf{perturb vs.~dampen electromagnetic resonances} within the particles, leading to different coupled responses in the total scattered energy and the angular distribution. This discovery provides unprecedented insights into how phase contrast and absorption processes distinctly modulate scattering properties and the angular distribution of scattered light, particularly in regimes dominated by resonance. It establishes that the specific formulation of $\widetilde{C}{\text{p}}$ used here is sensitive to the overall balance of multipole contributions, making it a valuable parameter for capturing refractive index-driven changes. }.