👉 Undiffractiveness, also known as diffractive refractive index, is a phenomenon in optics that describes how light behaves when it travels through a material. In other words, it's the ratio of the refractive index of the material to its optical density. The term "undiffractiveness" refers to the fact that the angle of refraction (the angle at which light is refracted) remains constant regardless of the orientation or direction of the incident light. This property is
