Quasinormal modes of Floquet media slabs

Our latest work, “Quasinormal modes of Floquet media slabs”, is now out in Physical Review B.

In this paper, we bring together quasinormal-mode theory and time-varying media to study electromagnetic scattering in slabs with time-periodic permittivity. By formulating and solving the associated nonlinear eigenvalue problem, we establish a QNM framework for Floquet media and derive a reduced-order model that efficiently captures the resonant physics of these systems. Beyond efficient computation of scattered fields, the framework provides physical insight into how temporal modulation couples to resonant modes, enabling tailored gain–loss engineering. We validate the approach numerically and demonstrate strategies to selectively amplify or suppress specific modal contributions.

As I usually try to do, the paper is accompanied by an open-source Python code. For me, open source is not just about reproducibility, but also about making advanced theoretical tools easier to explore, reuse, and build upon. You can find it here: github.com/benvial/pytmod

Happy to discuss or exchange ideas with anyone working on time-modulated media, resonances, or non-Hermitian wave physics.

Link for the paper: https://link.aps.org/doi/10.1103/xxnd-7d55