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 (n 1 ); - a first diffractive structure (S) etched on said first layer; - a second layer, covering at least part of said first structure, and having a spectral band of reflection in the visible spectrum; and in which: - said first diffractive structure is formed by a first pattern, said first pattern being formed by a set of modules disposed side-by-side, in a given direction (X) of arrangement; - 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 (Y), called direction of variation of the slope, perpendicular to the direction of arrangement (X); characterized in that : - the maximum width, defined in the direction of arrangement (X), of each module of the set of modules forming said first pattern of said first structure is less than 300 μm, said set of modules comprising a minimum number of modules such that a minimum dimension of the first structure along the direction of arrangement (X) is greater than 1 mm; and in that - said first pattern is modulated by a second pattern forming a periodic grating of period lying between 100 nm and 700 nm, determined to produce, after deposition of the second layer, a resonant filter in a given spectral resonance band, such that when the two modules are places side by side, the spectral resonance band is different between said two modules. - a first layer made of dielectric material, having a first refractive index (n 1 ); - a first diffractive structure (S) etched on said first layer; - a second layer, covering at least part of said first structure, and having a spectral band of reflection in the visible spectrum; - said first diffractive structure is formed by a first pattern, said first pattern being formed by a set of modules disposed side-by-side, in a given direction (X) of arrangement; - 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 (Y), called direction of variation of the slope, perpendicular to the direction of arrangement (X); - the maximum width, defined in the direction of arrangement (X), of each module of the set of modules forming said first pattern of said first structure is less than 300 μm, said set of modules comprising a minimum number of modules such that a minimum dimension of the first structure along the direction of arrangement (X) is greater than 1 mm; and in that - said first pattern is modulated by a second pattern forming a periodic grating of period lying between 100 nm and 700 nm, determined to produce, after deposition of the second layer, a resonant filter in a given spectral resonance band, such that when the two modules are places side by side, the spectral resonance band is different between said two modules. <EOS>