The Bloch-Mode Expansion: A new perspective for photonic crystal modeling

by Vincenzo Savona (Laboratory of Theoretical Physics of Nanosystems. Ecole Polytechnique Fédérale de Lausanne, Switzerland)

Monday 4 Feb 2013, 16:00 → 17:00 Europe/Rome

Aula Conversi (Dip. di Fisica - Edificio G. Marconi)

A frequent task, when modeling photonic crystal structures, is that of accounting for "small" perturbations of an otherwise periodic structure. This is for example the case when modeling the effect of disorder, or several designs of cavities with high quality factor. In such cases, a very natural strategy consists in expanding the electromagnetic modes on the basis of the Bloch modes of the underlying periodic structure. This Bloch-mode expansion can be very accurate if extended over several bands, while requiring a moderate computational effort, thus allowing the simulation of structures of record spatial extension. I will illustrate the Bloch-mode expansion method and review applications to several current problems. In particular I will discuss how realistic disorder affects the properties of one-dimensional waveguides, two-dimensional photonic crystals, and known designs of high-Q cavities. I will conclude by discussing how a photonic crystal waveguide can enforce long-range radiative excitation transfer between distant semiconductor quantum dots and the perspective for a viable design of an optical two-qubit quantum gate.