All-optical limiter photonic crystal with two-photon absorption

We present in this paper an original theory, modeling, and numerical calculations to make an all-optical limiter based on a two-photon absorption (TPA) nonlinear 2D parallel cylinders upon a triangular geometry photonic crystal in the visible domain. The structure could be either broadband or narrowband and is quasi-invariant to the incidence angle. The parameters used for the cylinders were extracted from the literature (combination of TiO₂ and nonlinear ZnO cylinders presenting TPA). This device could be useful, for instance, to protect photodetectors from an intense incident laser beam.