As light passes through an uncoated glass substrate,approximately 4% will be reflected at each surface.This result in a total transmission of only 92% of the incident light.Anti-Reflection coatings are especially important if the system contains many transmitting optical elements.Coationg each component will increase the throughput of the system and reduce hazards caused by reflections traveling backwards through the system(ghost images).Many low-light system incorporate AR coated optics to allow for an efficient use of the light.We now can provide many kinds of antireflective,high reflective and partial reflective coatings.