A pulsed finite-difference time-domain (FDTD) method for calculating lightscattering from biological cells over broad wavelength ranges

We combine the finite-difference time-domain method with pulse response tec hniques in order to calculate the light scattering properties of biological cells over a range of wavelengths simultaneously. The method we describe c an be used to compute the scattering patterns of cells containing multiple heterogeneous organelles, providing greater geometric flexibility than Mie theory solutions. Using a desktop computer, we calculate the scattering pat terns for common homogeneous models of biological cells and also for more c omplex representations of cellular morphology. We find that the geometry ch osen significantly impacts scattering properties, emphasizing the need for careful consideration of appropriate theoretical models of cellular scatter ing and for accurate microscopic determination of optical properties. (C)20 00 Optical Society of America.