Refraction of light

Knowing that light is a kind of energy, we may see that it can experience a variety of phenomena such as diffraction, reflection, refraction, interference, polarisation, and polarisation among others. When light moves from one medium to another, it experiences refraction, which occurs as a result of the bending of the light.

Refraction

In wave propagation, refraction is the bending of a wave as it travels from one medium to another. Specifically, the bending is induced by the variations in densities between the two materials. Refraction is defined as the shift in the direction of a wave when it passes through a medium. Refraction of light is one of the most often seen phenomena, although other waves such as sound waves and water waves are also subjected to refraction under certain circumstances. Our ability to use optical equipment such as magnifying glasses, lenses and prisms is made possible by the phenomenon of refraction. Additionally, it is because of the refraction of light that we are able to direct light onto our retina.

Refraction is caused by a variety of factors.

Change of Speed Results in Change in Direction/Medium

When a light beam enters a medium with a different refractive index than the media it is travelling through, it is said to be refracting. As a result of the change in speed, the direction of travel changes. Consider the case of air travelling into the water as an example. The speed of light decreases as it continues to move at a different angle from its original direction.

When the light goes from the air to the glass, it slows down and somewhat alters its direction. While travelling from a less dense to a denser material, the refracted light bends further towards the normal line than the incident light. The lightwave does not refract if it approaches the barrier in a direction that is perpendicular to it, despite the fact that its speed has increased.

The Refraction of Light is governed by several laws.

According to the laws of refraction, the incident ray, the refracted ray, and the normal interface of two media at the point of incidence all lie on the same plane at the point of incidence. 

The second law of refraction states that the relationship between the sine of the angle of incidence and the sine of the angle of refraction is constant. This is referred to as Snell’s law of refraction in some circles.

sin i ⁄ sin r =constant

Refractive Index

The refractive index, often known as the index of refraction, is a property of a substance that specifies how quickly light passes through it.

The refractive index is a one-dimensional quantity. The refractive index of a specific material is defined as the relationship between the speed of light in a vacuum (c) and the speed of light in the medium (m) (v). If the refractive index of a material is represented by the letter n, the refractive index may be calculated using the following formula:

n=c ⁄ v

The light beam changes its direction or bends at the junction separating the two mediums as a result of the refractive index of the medium. When a light beam goes from one medium to another with a higher refractive index, it bends in the direction of the normal; otherwise, it bends in the opposite direction of the normal.

Refraction of Light in Real Life

The optical illusions of mirage are created as a result of the refraction of light in the eye. Swimming pools appear shallower than they actually are because the light coming from the bottom of the pool bends at the top of the water as a result of the phenomenon known as refraction of light. As the sun’s rays bend through the raindrops, a rainbow appears. This is an example of refraction since the rainbow seems to be formed. Because of the refraction of light, when white light travels through a prism, it is broken down into its constituent colours and reassembled.

Conclusion

Therefore, we saw that there are several uses for refraction in optics and technology. A lens employs refraction to create a picture of an object that may be used for a variety of purposes, including magnification. The theory of refraction is used in the design of spectacles worn by persons who have poor eyesight. Refraction is utilised in a variety of applications including peepholes in home doors, cameras, movie projectors, and telescopes.