Simulation of the scattering properties of a chain-forming triangular prism oceanic diatom

The optical properties of diatom chains in the ocean are studied based on a combination of the many-body iterative T-matrix (MBIT) method and an improved implementation of the ray-by-ray (RBR) geometric optics method. The MBIT, a numerically accurate method, is advantageous for scatterers with linear cells. In contrast to other popular geometric optics methods, the RBR, an approximate method, considers the interference of all outgoing rays. The two methods are verified in comparison with benchmark simulations. The simulation results of diatom chains in a wide size range can be obtained with either or both methods, and each can be applied to any optically soft particle, i.e., in the case when relative refractive index approaches unity.