Modelling and fabrication of GaAs photonic-crystal cavities for cavity quantum electrodynamics

In this paper, we present recent progress in the growth, modelling, fabrication and characterization of gallium arsenide ( GaAs) two-dimensional (2D) photonic-crystal slab cavities with embedded indium arsenide ( InAs) quantum dots (QDs) that are designed for cavity quantum electrodynamics (cQED) experiments. Photonic-crystal modelling and device fabrication are discussed, followed by a detailed discussion of different failure modes that lead to photon loss. It is found that, along with errors introduced during fabrication, other significant factors such as the presence of a bottom substrate and cavity axis orientation with respect to the crystal axis, can influence the cavity quality factor ( Q). A useful diagnostic tool in the form of contour finite-difference time domain (FDTD) is employed to analyse device performance.