Edge elements: from Maxwell equations to photonic crystals


Lucia Gastaldi

Dipartimento di Matematica

Universita di Brescia, via Valotti 9 Brescia, Italy.

Photonic crystals are periodic structures composed of dielectric materials. The reason for the increase of the interest in this subject is that the spectrum of the Maxwell operator for such media is expected to have gaps. The presence of gaps means that there are prohibited frequencies of propagation of electromagnetic waves going through such crystals. This fact has many potential applications, for example, in optical communications, filters, lasers and microwaves. We analyze a finite element method based on a modification of Nedelec edge elements. We prove convergence of approximated eigensolutions to those of the continuous problem under general assumptions on the mesh. The main result requires minimal regularity hypotheses on the coefficients.