An optical assembly as well as methods for producing such

An optical assembly with a light source that emits coherent light, and an optical grating having a plurality of parallel, periodically successive in the spacing of a grating period following diffraction structures, a) are arranged on a base predetermining a carrier, b) each having a Littrow angle to the base comprise blaze flank inclined edge and a counter, and c) each having a reflective base layer and a base layer covering the transparent protective layer, characterized in that within each diffraction structures (3) the average thickness of layer (C