Waves in 1-D photonic crystals via quasi-normal-mode description

Summary form only given. During the last years an intense investigation on electromagnetic propagation phenomena at optical frequencies in periodic structures, usually referred as 1-D photonic crystals has been performed. Dispersive properties are usually evaluated assuming infinite periodic structures; the finite dimension of photonic crystals conceptually modify the calculation of dispersive properties: this is mainly due to the concept of energy flow through the crystal. A 1-D photonic crystal (1-D PC) is a dissipative system described by a nonhermitian Hamiltonian, therefore there is no orthogonal basis able to describe the field behavior, and consequently a correct dispersion relation. We have adopted a description of the scalar field in 1-D PC in terms of Quasi Normal Modes.