Disorder Limited Photon Propagation and Anderson Localisation in Photonic Crystal Waveguides

We investigate the disorder-limited propagation of photons in photonic crystal waveguides in the slow-light regime. We use analysis of Fabry-Perot resonances to map the mode dispersion and extract the photon localization length. Propagation lengths are deduced to be limited to less than 20 μm for group index >50. Anderson-localized modes are observed at high group indices, when the localization lengths are shorter than the waveguide lengths, consistent with the Fabry-Perot analysis. The results have consequences for integrated quantum-dot single-photon circuits which rely on slow-light effects to enhance emission rates.