ABSTRACT
Diffractive optics and holography are important domains in optics relying on the same physical phenomena of diffraction and interference to control the propagation of light. Whereas in diffractive optics the first structures were relatively simple grating-like structures, holograms were already complex volume patterns recorded by the interference of two beams scattered at 3D objects. The two domains were developing independently of each other until the invention of computer-generated holograms (CGHs) which are also called synthetic holograms. The first CGHs were line drawings of calculated interference patterns made by hand or by a pen plotter, nowadays modern microfabrication enables nearly arbitrary amplitude and phase structures with a resolution below the wavelength of light. Today, there is no accepted terminology that allows a clear distinction between a CGH or a diffractive element.
