Influence of Contamination with Silicone Release Agent on the Ellipsometric Parameters of CFRP Surface in the Sub-THz Range

This work is devoted to the experimental study of the effect of contamination of CFRP plates with silicone release agents on their ellipsometric parameters, and, accordingly, the possibility of ellipsometry to diagnose such contamination. As the studied objects, three series of CFRP samples, consisting of the initial (not contaminated) and contaminated samples, were used. In total, three degrees of contamination (concentration) with silicon were investigated: 5 at.%, 10 at.%, and 20 at.%. We used a quasi-optical sub-terahertz ellipsometer with an operating wavelength of 2.14 mm. It is shown that using sub-terahertz ellipsometry it is possible to reliably determine the concentration of silicon contamination of the CFRP surface. The ellipsometric parameters that are most sensitive to such contamination are determined.