Zone Plate

A zone plate is an optical device that focuses light using a series of concentric rings called zones. These zones are designed so that light passing through them interferes constructively at a specific point, creating a focus similar to a lens. Unlike traditional lenses, zone plates work primarily through diffraction, which bends and spreads light waves. They are often used in microscopy and x-ray imaging where traditional lenses are less effective. Zone plates are lightweight and can be manufactured for various wavelengths, making them versatile tools in scientific and industrial applications.