Density of states for finite photonic crystals

There is a twofold way to study wave propagation: one can deal with infinite structures and solve a spectral problem through Bloch waves or deal with a finite size device and solve a diffraction problem. In this work, we concentrate on scattering theory and we define a notion of scattering measure or reciprocal density of states, which plays the role of the classical local density of states for finite structures.