Fresnel zone plate

A Fresnel zone plate is an optical device that focuses light using a series of alternating transparent and opaque rings, called zones. Each zone is designed to allow light waves to interfere constructively, enhancing the focus at certain points. This principle exploits the wave nature of light, similar to how a lens works, but with a different structure. Fresnel zone plates are used in various fields, including microscopy and imaging, allowing for the capture of detailed images at smaller scales than conventional lenses, making them valuable in scientific research and telecommunications.