What is the Difference Between Total Internal Reflection and Refraction?

Total internal reflection and refraction are both optical phenomena that occur when light passes from one medium to another. However, they differ in the way light interacts with the boundary between the media.

Total Internal Reflection:

• Occurs when a ray of light reflects inside a medium instead of refracting, resulting in no refraction and following the law of reflection.
• Requires the angle of incidence to be greater than the critical angle.
• Only occurs when light is passing from a higher refractive index medium to a lower refractive index medium.
• Commonly used in optical devices such as prisms, optical fibers, and binoculars.

Refraction:

• Bending of light as it passes through a medium.
• Requires the angle of incidence to be less than the critical angle.
• Occurs when light passes from one medium to another with a different refractive index.
• Used in devices like cameras, telescopes, and eyeglasses.

In summary, total internal reflection occurs when light passes from a denser medium to a rarer medium and the angle of incidence is greater than the critical angle, resulting in the complete reflection of light. On the other hand, refraction occurs when light passes from one medium to another with a different refractive index, causing the light to change direction and bend towards the normal.

Comparative Table: Total Internal Reflection vs Refraction

Total Internal Reflection (TIR) and Refraction are two different phenomena that occur when light travels through different media. Here is a table summarizing the differences between the two:

In summary, TIR is a phenomenon where all the incident light is reflected back into the same medium it started from, occurring at the boundary between two media when the incident angle is greater than the critical angle and the second medium has a lower index of refraction than the first. Refraction, on the other hand, is the change in direction of light when it passes from one medium to another, occurring regardless of the incident angle and the density of the media involved.