Atmospheric pressure dielectric barrier discharges (DBDs), such as the micro cavity plasma
array (MCPA), have emerged as promising technologies for the conversion of volatile gases.
These conversion processes’ effectiveness can be enhanced by integrating catalytically active
surfaces. To deepen the understanding of the plasma-catalyst interaction, it is crucial to study
the transport dynamics of charged species to the catalytic surface, which, due to collisions with
neutrals, also directly affects the transport of reactive species to the catalyst. Thereby the
transport of the charged species is in particular influenced by the electric field perpendicular to
the catalytic surface. However, experimental data on the component-wise electric field strength
within SDBDs are rare. To address this issue, we performed polarized optical emission
spectroscopy on the shifting and splitting of the allowed 492.19nm and forbidden
492.06nm helium line pair. This diagnostic approach requires a non-radially
symmetric geometry, which leads to an adapted reactor design of the MCPA allowing the
side-on observation of the discharge. The discharge operates in pure helium at atmospheric
pressure, utilizing a triangular excitation voltage with a frequency of 15kHz and an amplitude
of 600V. We performed phase-resolved measurements of the electric field components with a
temporal resolution of 1µs. Our results revealed an electric field strength of approximately
22kV/cm for the component perpendicular to the dielectric surface, while the component
parallel to the dielectric surface is about 5kV/cm larger during the decreasing potential phase
of the applied voltage.