Interference and Diffraction
The proof of the wave nature of light came with the discovery of interference of light and diffraction. The wave nature of light will be studied with emphasis on two important wave phenomena, the diffraction and interference of light. This chapter describes that experiments designed to observe the diffraction patterns generated by objects, such as a blade, disk, washer, single-slit and double-slit holes, and grating. It aims to determine the locations of bright and dark fringes. Interference effects are commonly observed in thin films, such as soap bubbles and a thin layer of oil on the surface of water. Interference properties allow for the reduction of reflected light from the lenses, or the greater transmission of light, which is needed for exposing photographic film or for binocular viewing. The phenomenon of diffraction was explained in the time of Newton by assuming that light is composed of small particles.