Layer thicknesses are chosen to produce destructive interference in the beams reflected from the interfaces, and constructive interference in the corresponding transmitted beams. Many coatings consist of transparent thin film structures with alternating layers of contrasting refractive index. In other applications, the primary benefit is the elimination of the reflection itself, such as a coating on eyeglass lenses that makes the eyes of the wearer more visible to others, or a coating to reduce the glint from a covert viewer's binoculars or telescopic sight.
This is especially important in planetary astronomy. In complex systems such as cameras, binoculars, telescopes, and microscopes the reduction in reflections also improves the contrast of the image by elimination of stray light. In typical imaging systems, this improves the efficiency since less light is lost due to reflection. Note the tinted reflection from the coated lens.Īn antireflective, antiglare or anti-reflection ( AR) coating is a type of optical coating applied to the surface of lenses, other optical elements, and photovoltaic cells to reduce reflection. Uncoated glasses lens (top) versus lens with antireflective coating.
0 kommentar(er)
