Abstract: The present invention relates to a method and a corresponding apparatus for identifying a product (1) or information relating to the product (1). In the method, a concealed code on the product (1) is identified, wherein the code is given by a set of ellipsometric parameters, and the method comprises the following steps of: measuring ellipsometric variables for at least one defined point (8) on a surface (9) of the product (1), comparing the measured ellipsometric variables with at least one reference code, and determining a match between the measured ellipsometric variables and the reference code or one of the reference codes or determining a mismatch with each reference code.

Abstract: The present invention relates to a method and a corresponding apparatus for identifying a product (1) or information relating to the product (1). In the method, a concealed code on the product (1) is identified, wherein the code is given by a set of ellipsometric parameters, and the method comprises the following steps of: measuring ellipsometric variables for at least one defined point (8) on a surface (9) of the product (1), comparing the measured ellipsometric variables with at least one reference code, and determining a match between the measured ellipsometric variables and the reference code or one of the reference codes or determining a mismatch with each reference code.

Abstract: The present invention relates to a multilayer product (composite material), wherein the first layer is a layer which is optically dense in the infrared range, and wherein the second layer contains a polymer (plastics) as substrate. The invention additionally relates to a method of improving the flame resistance of mouldings made from polymers and to a method of producing the multilayer products as well as to components which contain the above-mentioned multilayer products.