In general, When a light ray is incident upon a boundary between a first transparent material and a second transparent material that has different index of refraction than the first material, a small amount of the light Will be reflected back into the first material and the remainder of the light Will be transmitted through the second material.

According to Snell’s Law, the angle of refraction Q2, Which describes the direction of propagation of the light being transmitted through the second material is dependent upon the angle of incidence Q1 of the light ray as measured With respect to a line normal to the boundary and it is dependent upon the ratio of the first material’s index of refraction n1 to the second material’s index of refraction n2. Snell’s Law can be expressed by Equation 2 below. n1 Sin(@1)=n2 Sin(@2)

Additionally, the angle of reflection @3 in the first material is equal to the angle of incidence Q1. If the angle of refraction O2 is greater than or equal to 90 degrees, the entire light ray is reflected and no light is transmitted through the second material. This phenomenon is known as total internal reflection, Which is the same principle according Which Waveguides function. Accordingly, light With an Equation 2. angle of incidence Q1 greater than the inverse sine of the second material’s index of refraction n2 divided by the first material’s index of refraction n1 Will be totally internally reflected (Total internal reflection occurs if (@1 >inv sin(n1/n2).

The index of refraction is the square root of the dielectric constant, which is a measure of the relative permittivity of the transparent material. Permittivity is the amount by which the material resists the formation of an electric field. The higher the permittivity, the lower the electric field. Accordingly, materials with different indexes of refraction have different electric field behaviors for the same photon.