File:Antireflection coating split pic.jpg

English: This photo shows an antirelection coated window. The window measures 2 inches (5.1 cm) square by 1/8 inch (3mm) thick. Made of borosilicate float-glass, the surface accuracy is 4λ per inch. The coating is a multilayer anti-reflection coat designed to give less than 0.5% reflection across the visual spectrum at a 0° angle of incidence. Transmittance is 96--99% between 400 and 700nm. The photo on the left shows the window when viewed at a 45° angle, reflecting the above fluorescent lighting in a rather purplish hue, which is common for antireflection coatings. This is due to the thickness of the coating upon the incident light, which causes it to shift toward the red and IR portion of the spectrum and allow reflections at the opposite end. The photo on the right shows the window when viewed at a 0° angle of incidence, for which the AR coating was designed, giving almost no reflection. (Some reflection of the camera and the photographer's face should normally be present.)