Guided wave measurements for characterization of sol-gel layers

Sol-gel applications require very thick layers with a good understanding of the interfaces. To address this problem, we have installed at CEA Le Ripault a characterization bench using guided waves with assistance from the IM2NP lab in Marseille. This bench allows us to measure the thickness and the refractive index and determine the extinction coefficient of a thin layer. We can distinguish losses at interfaces from those in the bulk according to the chosen propagation mode. This allows us to know if we can stack elementary layers to make thick layers without incurring problems.