Time-resolved ICCD images of discharge and plasma bullet formation in a capillary dielectric barrier discharge at atmospheric pressure have been obtained across the whole period in the voltage cycle. The images clearly show that the capillary discharge ignites at the inner edges of both electrodes, when each electrode is working as a cathode, and this leads to the formation of afterglow plasma bullets traveling upstream and downstream.

Time-resolved imaging of an array of silicon based micro-cavity discharge devices, operating in helium at 700 Torr, is presented. The array is shown to ignite four times per cycle, with the brightest emission corresponding to a distinct current peak in the negative phase of the applied sinusoidal voltage. The cavities do not ignite simultaneously and the instantaneous intensity across the array is non-uniform. Before the brightest emission peak is reached, optical imaging shows some of the cavities to be ignited. During the emission peak, neighboring cavities are successively ignited, resulting in two emission regions which propagate across the array with wavefront velocities of 3 and 6 km/s.