Light Scattering from Small Clusters of Chiral and Symmetric Particles: Shape-Dependent Analysis

We present a numerical study comparing light scattering by small clusters composed of helices, capsules, and spheres. Using the discrete-dipole approximation (DDA), we compute orientation-averaged Mueller-matrix elements M11, M12, and M14 for clusters with varying number of monomers (N = 5–45) and mean center-to-center separation (1–10 particle diameters). Our analysis isolates the influence of particle morphology on angular scattering intensity, linear polarization, and circular intensity differential scattering (CIDS), providing a direct comparison of symmetric and chiral shapes. Helices display persistent angular fine structure in M11 and deep, side-scattering maxima in M12, while spheres and capsules converge to smoother polarization curves with increasing separation. CIDS from symmetric monomers manifests as small oscillations around zero that decay rapidly with monomer separation and number. In contrast, helices produce a stable backward CIDS slope that is largely separation-independent but gradually flattens with increasing number of monomers. These trends confirm that morphology alone can influence key polarization characteristics and provide insights for interpreting scattering from complex-shaped particles. Such morphology-related features may help in the interpretation of polarization data in aerosol and planetary remote sensing and justify the refinement of the design of optical setups for studying irregular or chiral particles in controlled environments.