AR (Anti-Reflection) coated glass substrates are glass substrates that have been treated with a thin film coating to reduce the amount of light reflected from the surface of the substrate. This type of coating is typically used in optical applications, such as in displays, sensors, and solar cells, to improve the transmission of light through the substrate. The AR coating helps to reduce the amount of light that is reflected at the surface of the glass, allowing more light to pass through to the underlying material. This can result in higher efficiencies and improved performance in the final device. AR coatings are typically made of materials with a refractive index that is close to that of the glass substrate, and the thickness of the coating is carefully optimized to achieve the desired anti-reflection effect.