Transmission, reflection, and depolarization of an optical wave for a single leaf

Optical scattering by a single leaf is investigated, taking into account the structures inside a leaf and the leaf surface roughness. An optical scattering model, which includes both volume scattering and rough surface scattering, is developed using vector radiative transfer theory and Kirchhoff rough surface scattering theory. A leaf is modeled as a slab of water with an irregular surface containing randomly distributed spherical particles. The degree of polarization and the normalized scattering cross section per unit area for the transmitted and reflected copolarized and cross-polarized intensities are obtained for corn, potato, and laurel leaves. The theoretical results are compared with measured data to determine the parameters for the scatterers inside the leaf, the surface roughness, and the optical thickness. The agreement between the calculation and experiment for a wide variety of cases shows that this is a reasonable leaf model in the optical frequency regime.