Talbot effect

The Talbot effect is a phenomenon in optics where a pattern of light, such as a grid or grating, creates self-repeating images at specific distances from the original pattern when illuminated by a coherent light source like a laser. This occurs because the light waves interfere with each other, reconstructing the original pattern at regular intervals known as Talbot distances. Essentially, it’s like the pattern “reappears” or replicates itself along the light’s path, demonstrating the wave nature of light and how light waves can interfere constructively to produce repeated images without any lenses involved.