Refraction of Light Refraction is the bending of light as it passes from one medium to another. This phenomenon is responsible for the way that light can be...
Refraction of Light
Refraction is the bending of light as it passes from one medium to another. This phenomenon is responsible for the way that light can be used to create images, such as in a camera or a microscope.
When light enters a medium with a higher refractive index (a material with a greater density and speed of light), it bends away from the normal. This is due to the fact that light waves have more difficulty traveling through the denser medium.
As a result, light rays that enter a medium at an angle greater than the critical angle (the angle at which light would just begin to bend away from the normal) are refracted (bent) towards the normal. Conversely, light rays that enter a medium at an angle less than the critical angle are refracted away from the normal.
The degree of refraction depends on the properties of the two media and the angle of incidence. It can also be used to calculate the focal length of an optical instrument.
Examples:
When light enters water from air, it refracts away from the normal, causing it to bend downwards. This is responsible for the way that light is seen in a camera.
When light enters a glass plate, it refracts towards the normal, causing it to bend upwards. This is responsible for the way that light is seen in a microscope.
The refractive index of a material is typically higher for light waves with lower frequencies. This is why blue light, with its shorter wavelengths, is refracted more strongly than red light, with its longer wavelengths