# Refraction of Light

## Section Overview:

When electromagnetic radiation, in the form of visible light, travels from one substance or medium into another, the light waves may undergo a phenomenon known as refraction, which is manifested by a bending or change in direction of the light. Refraction occurs as light passes from one medium to another only when there is a difference in the index of refraction between the two materials. The effects of refraction are responsible for a variety of familiar phenomena, such as the apparent bending of an object that is partially submerged in water and the mirages observed on a dry, sandy desert. The refraction of visible light is also an important characteristic of lenses that enables them to focus a beam of light onto a single point.

### Introduction to the Refraction of Light

When electromagnetic radiation, in the form of visible light, travels from one substance or medium into another, the light waves may undergo a phenomenon known as refraction, which is manifested by a bending or change in direction of the light.

### Interactive Tutorials

• #### Refraction of Light

Explore how changes to the incident angle and refractive index differential between two dissimilar media affect the refraction angle of light at the interface in this interactive tutorial.

• #### Observing Objects in Water

Objects seen in the water will appear to be at a different depth than it actually is, due to the refraction of light rays. Discover how fish, observed from the bank of a pond or lake, appear to be closer to the surface than they really are.

• #### Refraction by an Equilateral Prism

Explore how the incident angle of white light entering the prism (also known as dispersion) affects the degree of dispersion and the angles of light exiting the prism in this interactive tutorial.

• #### The Critical Angle of Reflection

Learn as this tutorial explains critical angle of reflection by exploring the transition from refraction to total internal reflection as the angle of the incident wave is increased at constant refractive index.

• #### Beam Steering by Wedge Prisms

Prisms positioned at slight angles with respect to each other are termed optical wedges, and deflect light by refraction rather than reflection. Examine how two wedge prisms operate together to deflect an incident light beam.

• #### Refraction of Monochromatic Light

Discover how changes to the incident angle and refractive index differential between two dissimilar media affect the refraction angle of monochromatic light at the interface in this interactive tutorial.

### Selected Literature References

The reference materials listed in this section are an excellent source of additional information on the diverse topic of light refraction and dispersion by isotropic and anisotropic media. Included are references to books, book chapters, and review articles, which discuss the theory and applications of the refraction and refractive index, and how they relate to the physics of light and color.

#### Contributing Authors

Matthew J. Parry-Hill, Robert T. Sutter, Thomas J. Fellers and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.