
A calculator that uses Snell's law to calculate the angle of refraction and the critical angle for total internal reflection is presented.
n_{1} sin α = n_{2} sin β Using Snell's law given above, we can solve for β to obtain β = sin^{1}(n_{1} sin α / n_{2}) In many applications, we need total internal reflection of light within medium (1). Optical fibers are examples of systems where total internal reflection of light is used to carry light between distant points. The angle of incidence α_{c} corresponding to β = 90 ° is called the critical angle and is given by Snell's law as follows n_{1} sin α_{c} = n_{2} sin 90° sin α_{c} = n_{2} / n_{1} α_{c} = sin^{1}(n_{2} / n_{1}) If light rays are incident on a surface separating two media of indices n_{1} > n_{2}, total internal reflection occurs if the angle of incidence α is greter than the critical angle α_{c}. This calculator computes the angle of refraction β using Snell's law and the critical angle α_{c} given above. NOTE that the critical angle α_{c} exixts only if n_{1} > n_{2} and also angle β can be calculated if n_{1} sin α / n_{2} ≤ 1
Refraction and Critical Angles CalculatorEnter the indices n_{1} and n_{2} and the angle of incidence α in degrees then press "Calculate Angles".More References and LinksTotal Internal Reflection of Light Rays at an Interface, Examples and Solutions.Refraction of Light Rays, Examples and Solutions Optical Fibers 