Spatially Resolved Ozone Density in Volumetric and Surface Dielectric Barrier Discharges via Absorption Spectroscopy*

Absorption spectroscopy is performed on two different Dielectric Barrier Discharges, a Surface (SDBD) and a Volumetric (VDBD), in order to measure the Ozone (O$_3$) density within the gas phase. A Laser Driven Light Source (LDLS) is used as a very stable, high intensity broad-band source between 170 nm and 2400 nm. The light emitted from the collimated LDLS and the plasma are shown through a narrow band filter at 253.7 $\pm$ 5 nm to isolate the O$_3$ Hartley band centered about 253.65 nm. Absorption measurements are performed on both the SDBD and VDBD at atmospheric pressure under varying gas mixtures and at flows of 10 slm and 2 slm, respectively. Spatial resolution is achieved on the order of 0.1 mm with a CCD camera. Furthermore, measurements are taken at multiple frequencies and peak to peak voltages resulting in varying power densities. A direct comparison of the gas phase O$_3$ is made at the same operating frequency and power density of the two plasma sources.