Anti-reflecting (AR) coating is used to reduce reflection and enhance transmission.It’s idea for optical window use.AR coatings are often crucial components in optical systems with multiple lenses or other optics where the maximum possible light energy is needed. AR coatings help to produce brighter images. AR coatings also reduce the intensity of ghost images which are sometimes produced in optical systems by multiple reflecting surfaces.

BBAR means broad band anti-feflective. AR reflective coating sometimes is used together with anti-scratch coating on optical windows.