Optical security component visible in reflection, manufacture of such a component, and secure document provided with such a component

An optical security component intended to be observed in reflection, with the naked eye, according to at least one first observation face, comprising:

• a first layer made of dielectric material, having a first refractive index;
• at least one first diffractive structure etched on said first layer;
• and in which:
• said at least one first diffractive structure is formed of a first pattern, wherein said first pattern is formed of a set of modules disposed side-by-side, in a direction of arrangement, a maximum width of each module defined in the direction of arrangement being less than 300 μm, wherein said set of modules comprises a minimum number of modules so that a minimum dimension of said at least one first diffractive structure in the direction of arrangement is greater than 1 mm;
• each module comprises a bas-relief with a first set of facets whose forms are determined to simulate an optical element visible in reflection, with at least one convex region and/or at least one concave region, having a profile with a variable slope in a single direction, called direction of variation of the slope, at right angles to the direction of arrangement;
• for two modules disposed side-by-side, the slope, in said direction of variation of the slope, is different between said two modules along at least one line parallel to the direction of arrangement;
• the optical security component having, in reflection and under the effect of a tilt movement about an axis parallel to said direction of arrangement, a dynamic visual effect comprising a movement of one or more graphic elements.