Abstract: According to the inventive method for determining the thickness of at least one layer provided on a substrate, the measurement can be constructed simply and reliably and a reliable measuring result can be obtained by measuring reflection—and/or transmission light intensity values of zero order in dependence on the wavelength and calculating said reflection—and/or transmission light intensity values using an iteration model which is dependent on the individual layer parameters. The layer parameters are altered in order to introduce a consistency between the measured values and the calculated values and the substrates have geometrical structures whose geometrical dimensions are used as further parameters of the iteration model. The inventive method also provides a means of determining the geometry of structures in the substrate, for example the depth, width and the repetition interval of grooves in a blank for geometrical storage media, such as CDs.

Abstract: A method for regulating a coating process for the application of a layer onto a substrate having a diffracted structure is provided. The intensity of a light bundle falling onto a coated substrate and diffracted thereby is determined after transmission and/or reflection of the light bundle for at least the first order or a higher order, and this intensity is utilized as the actual value for regulating the layer thickness.

Abstract: A holographic mirror is made by a process of continuous exposure. For this purpose, a photosensitive layer (10) is exposed strip by strip in a direction crosswise to that in which the layer is exposed by two interfering beams (6, 6'). Film (11) bearing photosensitive layer (10) is continuously moved in the longitudinal direction (F) at a speed that ensures sufficient exposure of the layer. The procedure makes it possible to produce holograms of any length in one direction.