Nonlinear photonic crystals in chalcogenide films

Abstract

All optical switching devices based on kerr-effect, where light switches light, are enjoying renewed interest. The dream of ultra compact devices operating at very low power and integrable on a chip is entering the realm of reality thanks to the advent of photonic crystal, enabling high Q/V ratio. We show that marrying photonic crystal and a new class of highly non linear material, Chalcogenide glasses, is a very promising way to achieve an all-optical chip. We describe the fabrication techniques we have developed for manufacturing two-dimensional Chalcogenide photonic crystal. Different types of photonic crystal resonances are investigated. Coupling technique to chalcogenide based photonic crystal waveguides and cavities via tapered nanowires is thoroughly described. We demonstrate resonant guiding in a chalcogenide glass photonic crystal membrane using a fano probe technique. We observe strong resonances in the optical transmission spectra at normal incidence, associated with Fano coupling between free space and guided modes. We obtain good agreement with modeling results based on three-dimensional finite-difference time-domain simulations, and identify the guided modes near the centre of the first Brillouin zone responsible for the main spectral features.