The electromagnetic optical theorem revisited

We revisit the optical theorem relevant to the far-field electromagnetic scattering by an arbitrary particle. We compute both the Poynting vector and the energy density of the total field and demonstrate once again that, despite a recent claim to the contrary, the extinction is caused by the interference of the incident and the forward-scattered field. However, caution must be exercised when one describes electromagnetic scattering using a formalism based on the coherency dyad since this approach may lead to unphysical artifacts.