An array of microcavity plasma devices is formed in a ceramic substrate that provides structure for and isolation of an array of microcavities that are defined in the ceramic substrate. The ceramic substrate isolates the microcavities from electrodes disposed within the ceramic substrate. The electrodes are disposed to ignite a discharge in microcavities in the array of microcavities upon application of a time-varying potential between the electrodes. Embodiments of the invention include electrode and microcavity arrangements that permit addressing of individual microcavities or groups of microcavities. The contour of the microcavity wall allows for the electric field within the microcavity to be shaped.