Refraction Refraction

Refraction of Light Refraction – the bending of a wave disturbance as it passes at an angle from one medium into another Light bends whenever it changes media except when it strikes the boundary parallel to the normal The angle between the normal and the incoming ray is called the angle of incidence (θi) The angle between the normal and the outgoing ray is called the angle of refraction (θr)

Refraction of Light

Refraction of Light Refraction symbolizes that the wave is changing speed When light speeds up, it bends away from the normal θi < θr When light slows down, it bends toward the normal θi > θr Crossing a boundary typically causes reflection as well as refraction

The Law of Refraction Index of refraction – the ratio of the speed of light in a vacuum to its speed in a given transparent medium Index of refraction = (speed of light in a vacuum)/(speed of light in medium) n=c/v Can also be calculated using the wavelengths We will assume air to essentially be a vacuum for index of refraction problems

The Law of Refraction

The Law of Refraction Refraction causes objects to appear in different locations than they actually are Wavelength affects the index of refraction Each color of visible light refracts differently from the others Snell’s Law determines the angle of refraction ni(sinθi) = nr(sinθr) (Index of refraction for the initial medium) * (sine of the angle of incidence) = (index of refraction for the second medium) *(the angle of refraction)

The Law of Refraction