A method including depositing a suspension of a colloid comprising an amount of nano-particles of a ceramic material on a substrate; and thermally treating the suspension to form a thin film. One or more projections extend from the first side of substrate assembly. The method also includes supplying at least a second optical pulse to the photo-detector causing a change in the resonant signal, wherein the second optical pulse is reflected from the object, monitoring the change in the resonant signal, and determining a position of the object based on the monitored change in the resonant signal. Thermal contact can then be made to the diamond layer to conduct heat away from the one or more semiconductor layers. By improving the impregnability in the thickness direction of the preform, an FRP excellent both in various mechanical properties and in matrix resin impregnation and stabler in quality can be produced with high productivity. The process includes an injection molding in a mold, a vacuum water extraction, and a demolding the fresh article.