The serrated DBD plasma actuator configuration, with the exposed electrode having a sawtooth edge, was compared to the standard one (i.e. with strip electrodes) in order to highlight plasma channels induced by the serration. The differences in the plasma morphology and properties between these configurations were investigated by using optical diagnostics, in quiescent air. Images of the discharge were recorded by an ICCD camera, with and without narrow-band filters and an optical emission spectrometer was used to measure the spectral bands of N2 and N2+, allowing the rotational temperatures to be estimated.