F

Any interface where the index of refraction differs will cause light to be reflected, known as Fresnel reflection. The reflection coefficient R can be quantified by the following expression for light incident normal to an interface between two materials, moving from a material of index n₁ into another of index n₂

Between a typical glass-air interface, such as that of a flat cleaved fiber (normal incidence), the end reflection is around 4%.

Related Terms: End Face