Large dispersion in photonic crystal waveguide resonator

Group delay and chromatic dispersion of a Fabry-Pérot resonator embedded in a photonic crystal waveguide have been directly measured at 1.55 µm wavelength using the phase-shift technique. The photonic crystal waveguide resonator was fabricated in an InGaAsP/InP heterostructure and was designed to show a channel spacing of 100 GHz. Group velocity dispersion up to 250 ps/nm was observed.