Reflection principle for the Maxwell equations and its application to inverse electromagnetic scattering

A novel reflection principle for the time-harmonic Maxwell equations is established. It is then used to derive a uniqueness result in inverse electromagnetic obstacle scattering with polyhedral-type scatterers of perfect conductors. The underlying scatterers can be very general; e.g., they may consist of finitely many solid polyhedra along with finitely many subsets of two-dimensional planes.