BBAR Coating means Broadband anti-reflective coating. Broadband anti-reflective (BBAR) coatings consist of multiple layers, alternating between a high index material and a low index material. The layers are deposited on the substrate via electron-beam deposition. The thickness of the layers is optimized, using modeling software, to produce destructive interference between reflected waves and constructive interference between transmitted waves. This results in an optic that has enhanced performance within a specified wavelength band as well as minimal internal reflections (ghosting). Yutai's BBAR coatings provide good performance for angles of incidence between 0° and 30° and a numerical aperture (NA) of 0.5.