diffraktiograveerauksia

Diffraktiograveerauksia, known in English as diffractive engravings or holographic engravings, are microscopic structures imprinted onto a surface that create a visual effect by diffracting light. Unlike traditional engravings that rely on physical depth to create shadows and highlights, diffractive engravings manipulate the path of light itself. These structures are typically on the order of the wavelength of visible light, meaning they are incredibly small, often in the nanometer range.

The creation of diffractive engravings involves sophisticated lithographic techniques. These can include electron-beam lithography or deep ultraviolet lithography to etch precise patterns onto a substrate. The resulting patterns, when illuminated, cause light waves to interfere constructively and destructively, producing iridescent colors, holographic images, or other optical phenomena. This effect is often seen in security features on currency, credit cards, and identification documents, where the complex patterns are difficult to counterfeit.

The visual appearance of a diffractive engraving can change dramatically depending on the angle of observation and the illumination source. This dynamic quality makes them useful for decorative purposes as well as for security. The underlying principle is based on the physics of diffraction, where light bends as it passes by or through an obstacle or aperture. By precisely controlling the shape and spacing of these micro-structures, designers can engineer specific visual outcomes.