What are the best examples of total internal reflection?

Best Examples of Total Internal Reflection

Total Internal Reflection (TIR) is an optical phenomenon that occurs when a wave strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. If the refractive index is lower on the other side of the boundary, no light can pass through, and all of it is reflected. The following are some of the best examples of total internal reflection:

1. Optical Fibers

Optical fibers utilize total internal reflection to transmit light over long distances with minimal loss. The core of the fiber has a higher refractive index than the cladding, ensuring that light signals are guided along the fiber through TIR.

2. Diamonds

Diamonds sparkle intensely because of total internal reflection combined with their high refractive index. The cut of a diamond is designed to maximize light entering the diamond to be internally reflected and refracted, enhancing its brilliance.

3. Mirage

A mirage is a naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky. It is an example of total internal reflection occurring due to the variation of air temperature and, consequently, the refractive index with height above the ground.

4. Prism Periscopes

Prism periscopes, used in submarines and tanks, rely on total internal reflection. Two prisms are arranged so that light entering the first prism is totally internally reflected by both prisms, allowing observers to see over or around obstacles.

5. Rainbows

Rainbows are a result of total internal reflection and dispersion of light in water droplets. This process separates sunlight into its component colors, creating a spectrum that appears as a circular arc in the sky.

6. Binoculars

High-quality binoculars use prisms to reflect light through their length to allow for a more compact design. Total internal reflection in the prisms ensures that light is efficiently transmitted through the binoculars, providing a bright and clear image.